majic-ansible-roles Changeset

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Branko Majic (branko) - 5 years ago 2021-01-18 22:33:44
branko@majic.rs

MAR-151: Fix The Bug Genie backup example in usage instructions:

- Properly set-up the directory where files are uplaoded.
- Update instructions to mention what needs to be done in order to
upload some files in The Bug Genie.

1 file changed with 24 insertions and 3 deletions:

docs/usage.rst

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 .. _usage:
 Usage
 =====
 Majic Ansible Roles are targeted at sysadmins who wish to deploy services for
 their own, small-scale use. This chapter gives a simple tutorial-like set of
 instructions for using all of the roles available.
 .. contents:: :local:
 Overview
 --------
 There is a number of different roles that can prove useful for setting-up a
 small infrastructure of your own.
 Some roles are suited for one-off operations during installation, like the
 ``preseed`` and ``bootstrap``, while some are better suited for periodic runs
 for maintaining the users and integrity of the system.
 By the end of following the instructions, you will have the following:
 * Ansible server, used as controller for configuring and managing the
   remaining servers.
 * Communications server, providing the LDAP, mail, and XMPP services.
 * Web server, providing the web services.
 * Backup server, used for storing all of the backups.
 .. warning::
    Majic Ansible Roles support *only* Python 3 - both on the
    controller side and on the managed servers side.
    It is important to make sure that both the controller Python
    virtual environment used for Ansible *and* the interpreter for
    remote servers are *both* set-up to use Python 3.
    Python 3 is specified explicitly during virtual environment
    creation and in ``ansible.cfg`` configuration file
    (``interpreter_python`` option under ``defaults`` section).
 Pre-requisites
 --------------
 For the set-up outlined in this usage guide you'll need the following:
 * One server where Ansible will be installed at. Debian Buster will
   be installed on top of this server. The server will be set-up
   manually (this is currently out of scope for the *Majic Ansible
   Roles* automated set-up).
 * Three servers where the services will be set-up. All servers must be able to
   communicate over network with each-other, the Ansible servers, and with
   Internet. Debian Buster will be installed on top of this server as part of the
   usage instructions.
 * Debian Buster network install CD.
 * All servers should be on the same network.
 * IP addresses for all servers should be known.
 * Netmask for all servers should be known.
 * Gateway for all servers should be known.
 In case of the servers listed above, it might be safest to have them as VMs -
 this is cheapest thing to do, and simplest (who wants to deal with pesky hardware anyway?).
 Usage instructions assume the following:
 * Domain used for all servers is ``example.com``. If you wish to use a different
   domain, adjust the instructions accordingly.
 * Server hostnames are ``ansible``, ``comms``, ``www``, and ``bak`` (for Ansible
   server, communications server, web server, and backup server, respectively).
 Installing the OS on Ansible server
 -----------------------------------
 Start-off by installing the operating system on the Ansible server:
 . Fire-up the ``ansible`` server, and boot from the network installation CD.
 . Select the **Install** option.
 . Pick **English** as language.
 . Pick the country you are living in (or whatever else you want).
 . Pick the **en_US.UTF-8** locale.
 . Pick the **American English** keymap.
 . Configure the network if necessary.
 . Set the hostname to ``ansible``.
 . Set the domain to ``example.com``.
 . Set the root password.
 . Create a new user. For simplicity, call the user **Ansible user**, with
     username **ansible**.
 . Set-up partitioning in any way you want. You can go for **Guided - use
     entire disk** if you want to keep it simple and are just testing things.
 . Wait until the base system has been installed.
 . Pick whatever Debian archive mirror is closest to you.
 . If you have an HTTP proxy, provide its URL.
 . Pick if you want to participate in package survey or not.
 . Make sure that at least the **standard system utilities** and **SSH server**
     options are selected on task selection screen.
 . Wait for packages to be installed.
 . Install the GRUB boot loader on MBR.
 . Finalise the server install, and remove the installation media from server.
 Installing required packages
 ----------------------------
 With the operating system installed, it is necessary to install a couple of
 packages, and to prepare the environment a bit on the Ansible server:
 . Install the necessary system packages (using the ``root`` account)::
      apt-get install -y virtualenv virtualenvwrapper git python3-pip python3-dev libffi-dev libssl-dev
 . Set-up the virtual environment (using the ``ansible`` account):
    .. warning::
       If you are already logged-in as user ``ansible`` in the server, you will
       need to log-out and log-in again in order to be able to use
       ``virtualenvwrapper`` commands!
    ::
      mkdir ~/mysite/
      mkvirtualenv -p /usr/bin/python3 -a ~/mysite/ mysite
      pip install -U pip setuptools
      pip install 'ansible~=2.9.0' dnspython
 .. warning::
    The ``dnspython`` package is important since it is used internally via
    ``dig`` lookup plugin.
 Cloning the *Majic Ansible Roles*
 ---------------------------------
 With most of the software pieces in place, the only missing thing is the Majic
 Ansible Roles:
 . Clone the git repository::
      git clone https://code.majic.rs/majic-ansible-roles ~/majic-ansible-roles
 . Checkout the correct version of the roles::
      cd ~/majic-ansible-roles/
      git checkout -b 5.0-dev 5.0-dev
 Preparing the basic site configuration
 --------------------------------------
 Phew... Now that was a bit tedious and boring... But at least you are now ready
 to set-up your own site :)
 First of all, let's set-up some basic directory structure and configuration:
 . Create Ansible configuration file.
    .. warning::
       Since Ansible 2.x has introduced much stricter controls over security of
       deployed Python scripts, it is recommended (as in this example) to use the
       ``pipelining`` option (which should also improve performance). This is in
       particular necessary in cases where the SSH user connecting to remote
       machine is *not* ``root``, but there are tasks that use ``become`` with
       non-root ``become_user`` (which is the case in Majic Ansible Roles). See
       `official documentation
       <https://docs.ansible.com/ansible/latest/become.html#becoming-an-unprivileged-user>`_
       and other alternatives to this.
    :file:`~/mysite/ansible.cfg`
    ::
      [defaults]
      roles_path=/home/ansible/majic-ansible-roles/roles:/home/ansible/mysite/roles
      force_handlers = True
      inventory = /home/ansible/mysite/hosts
      interpreter_python = /usr/bin/python3
      [ssh_connection]
      pipelining = True
 . Create directory where retry files will be stored at (so they woudln't
    pollute your home directory)::
      mkdir ~/mysite/retry
 . Create the inventory file.
    :file:`~/mysite/hosts`
    ::
      [preseed]
      localhost ansible_connection=local
      [communications]
      comms.example.com
      [web]
      www.example.com
      [backup]
      bak.example.com
 . Create a number of directories for storing playbooks, group
    variables, SSH keys, X.509 artefacts (for TLS), and GnuPG keyring
    (we'll get to this later)::
      mkdir ~/mysite/playbooks/
      mkdir ~/mysite/group_vars/
      mkdir ~/mysite/ssh/
      mkdir ~/mysite/tls/
      mkdir ~/mysite/gnupg/
 . Create SSH private/public key pair that will be used by Ansible for
    connecting to destination servers, as well as for some roles::
      ssh-keygen -f ~/.ssh/id_rsa -N ''
 Protecting communications using TLS
 -----------------------------------
 In order to protect the communications between users and servers, as
 well as between servers themselves, it is important to set-up and
 properly configure TLS for each role.
 *Majic Ansible Roles* mandates use of TLS wherever possible. In other
 words, *you must* have TLS private keys and certificates issued by
 some CA for all servers in order to be able to use most of the
 roles. The private keys and certificates are primarily meant to be
 generated *per service*, and that is the approach we will pursue here
 as well.
 TLS private keys should be ideally generated locally and kept in a
 safe environment (possibly encrypted until needed), while the X.509
 certificates should be issued by a relevant certification
 authority. You can choose to roll-out your own CA, use one of the
 public CAs, or perhaps go for a mix of both.
 For the purpose of this guide, we'll set-up a small simple local CA to
 issue all the necessary certificates, and we'll generate the private
 keys and issue server certificates on the go as needed, storing them
 all under the ``~/mysite/tls/`` directory.
 So, let us make a slight detour to create a CA of our own:
 . First off, install a couple more tools on the Ansible server. We
    will be using ``certtool`` for our improvised CA needs (run this as
    ``root``)::
      apt-get install -y gnutls-bin
 . Create a template for the ``certtool`` so it would know what
    extensions and content to have in the CA certificate:
    :file:`~/mysite/tls/ca.cfg`
    ::
       organization = "Example Inc."
       country = "SE"
       cn = "Example Inc. Test Site CA"
       expiration_days = 1825
       ca
       cert_signing_key
       crl_signing_key
 . Almost there... Now let us generate the CA private key and
    self-signed certificate::
      certtool --sec-param high --generate-privkey --outfile ~/mysite/tls/ca.key
      certtool --template ~/mysite/tls/ca.cfg --generate-self-signed --load-privkey ~/mysite/tls/ca.key --outfile ~/mysite/tls/ca.pem
 . And just one more small tweak - we need to provide a truststore PEM
    file containing all CA certificates in the chain for services to be
    able to connect to each-other (where necessary). In this particular
    case we have a super-simple hierarchy (root CA is also issuing the
    end entity certificates), so simply make a copy of the ``ca.pem``::
      cp ~/mysite/tls/ca.pem ~/mysite/tls/truststore.pem
 .. note::
    A useful feature that all roles implement is a check to see if
    certificates will expire within the next 30 days. This check is
    performed via cronjob at midnight, and failing results will end-up
    being delivered to the ``root`` user on local server. Later on,
    once you have configured the mail server, you should be able to
    set-up the necessary aliases to have the mails delivered to
    non-local accounts too.
 Preseed files
 -------------
 The ``preseed`` role is useful for generating Debian preseed files. Preseed
 files can be used for automating the Debian installation process.
 Preseed files are created on the Ansible controller, and then supplied
 to Debian installer.
 So, let's set this up for start:
 . First of all, create the playbook for generating the preseed files locally.
    :file:`~/mysite/playbooks/preseed.yml`
    ::
       ---
       - hosts: preseed
         roles:
           - preseed
 . Now we need to configure the role. Two parameters are mandatory -
    one that specifies where the preseed files are to be stored, and
    one that specifies the public key that should be used to
    pre-populate the SSH authorized keys for the ``root`` account. This
    is required for the initial bootstrap of servers because Debian
    GNU/Linux does not by default allow the ``root`` user to
    authenticate via SSH using a password. We will use the SSH public
    key generated earlier via the ``ssh-keygen`` command. Create the
    configuration file:
    :file:`~/mysite/group_vars/preseed.yml`
    ::
       ---
       # Public key used to authenticate remote logins via SSH for the
       # root account.
       ansible_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
       # Directory where the preseed files will be output to.
       preseed_directory: "~/mysite/preseed_files/"
 . Now we can generate the pressed files::
      workon mysite && ansible-playbook playbooks/preseed.yml
 . If all went well, you should have the following files created:
    * :file:`~/mysite/preseed_files/comms.example.com.cfg`
    * :file:`~/mysite/preseed_files/www.example.com.cfg`
    * :file:`~/mysite/preseed_files/bak.example.com.cfg`
 . You can have a look at them, but you might notice the settings in the file
    might not be to your liking. In particular, it could be using wrong timezone,
    defaulting to DHCP for network configuration etc. Let's concentrate on making
    the network configuration changes - this is the main thing that will probably
    differ in your environment. Update the preseed configuration file:
    :file:`~/mysite/group_vars/preseed.yml`
    ::
       ---
       # Public key used to authenticate remote logins via SSH for the
       # root account.
       ansible_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
       # Directory where the preseed files will be output to.
       preseed_directory: "~/mysite/preseed_files/"
       # Set your default (initial) root password.
       preseed_root_password: changeit
       # Use manual network configuration (no DHCP).
       preseed_network_auto: no
       # Set the gateway for all servers.
       preseed_gateway: 10.32.64.1
       # Set the netmask for all servers.
       preseed_netmask: 255.255.255.0
       # Set the DNS for all servers.
       preseed_dns: 10.32.64.1
       # Set the domain for all servers.
       preseed_domain: example.com
       # Set the server-specific options.
       preseed_server_overrides:
         comms.example.com:
           hostname: comms
           ip: 10.32.64.19
         www.example.com:
           hostname: www
           ip: 10.32.64.20
         bak.example.com:
           hostname: bak
           ip: 10.32.64.23
 . Now re-run the preseed playbook::
      workon mysite && ansible-playbook playbooks/preseed.yml
 . The preseed files should have been updated now, and you should have the new
    customised configuration files in the ``preseed_files`` directory. You can
    now use these to install the servers.
 Installing the servers with preseed files
 -----------------------------------------
 You have your preseed files now, so you can go ahead and install the
 servers ``comms.example.com``, ``www.example.com``, and
 ``bak.example.com`` using them with network install CD. Have a look at
 `Debian instructions
 <https://www.debian.org/releases/buster/amd64/apb.en.html>`_ for
 more details.
 If you need to, you can easily serve the preseed files from the Ansible server
 with Python's built-in HTTP server::
   cd ~/mysite/preseed_files/
   python3 -m http.server 8000
 Then you can point installer to the preseed file selecting the
 ``Advanced options -> Automated install`` (don't press ``ENTER`` yet),
 then pressing ``TAB``, and appending the following at the end (just
 fill-in the correct hostname - ``comms``, ``www``, or ``bak``)::
   url=http://ansible.example.com:8000/HOSTNAME.example.com.cfg
 Bootstrapping servers for Ansible set-up
 ----------------------------------------
 In order to effectively use Ansible, a small initial bootstrap always has to be
 done for managed servers. This mainly involves set-up of Ansible users on the
 destination machine, and distributing the SSH public keys for authorisation.
 When you use the preseed configuration files to deploy a server, you get the
 benefit of having the authorized_keys set-up for the root operating system user,
 making it easier to bootstrap the machines subsequently via Ansible.
 Let's bootstrap our machines now:
 . For start, create a dedicated playbook for the bootstrap process.
    :file:`~/mysite/playbooks/bootstrap.yml`
    ::
       ---
       - hosts:
           - communications
           - web
           - backup
         remote_user: root
         roles:
           - bootstrap
 . The ``bootstrap`` role has only one parameter - an SSH key which
    should be deployed for the Ansible user on managed server (in the
    ``authorized_keys`` file). Since this role is applied against all
    servers, we will use the same value everywhere. Configure the role:
    :file:`~/mysite/group_vars/all.yml`
    ::
       ---
       ansible_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
 . SSH into all machines at least once from the Ansible server in order to
    store the SSH fingerprints into known hosts file::
      ssh root@comms.example.com date && \
      ssh root@www.example.com date && \
      ssh root@bak.example.com date
 . Now, simply run the bootstrap role against the servers::
      workon mysite && ansible-playbook playbooks/bootstrap.yml
 . At this point you won't be able to ssh into the machines with the
    ``root`` account anymore. You will be able to ssh into the machines
    using the ``ansible`` user (from the Ansible server). The
    ``ansible`` user will also be granted ability to run the ``sudo``
    commands without providing password.
 . Now you can finally move on to configuring what you really want -
    common configuration and services for your site.
 Common server configuration
 ---------------------------
 Each server needs to share some common configuration in order to be functioning
 properly. This includes set-up of some shared accounts, perhaps some hardening
 etc.
 .. note::
    Should you ever need to limit what hosts can connect to a server
    for some kind of maintenance or upgrade purposes, the ``common``
    role comes with ``maintenance`` and ``maintenance_allowed_hosts``
    parameters. See :ref:`rolereference` for more information.
 Let's take care of this common configuration right away:
 . Create playbook for the communications server:
    :file:`~/mysite/playbooks/communications.yml`
    ::
       ---
       - hosts: communications
         remote_user: ansible
         become: yes
         roles:
           - common
 . Create playbook for the web server:
    :file:`~/mysite/playbooks/web.yml`
    ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
 . Create playbook for the backup server:
    :file:`~/mysite/playbooks/backup.yml`
    ::
       ---
       - hosts: backup
         remote_user: ansible
         become: yes
         roles:
           - common
 . Create the global site playbook:
    :file:`~/mysite/playbooks/site.yml`
    ::
       ---
       - import_playbook: preseed.yml
       - import_playbook: communications.yml
       - import_playbook: web.yml
       - import_playbook: backup.yml
 . Time to create configuration for the role. Since this role is supposed to
    set-up a common base, we'll set-up the variables file that applies to all
    roles:
    :file:`~/mysite/group_vars/all.yml`
    ::
       ---
       ansible_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
       os_users:
         - name: admin
           uid: 1000
           additional_groups:
             - sudo
           authorized_keys:
             - "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
           password: "{{ 'admin' | password_hash('sha512') }}"
       common_packages:
         - emacs25-nox
       ca_certificates:
         truststore: "{{ lookup('file', '~/mysite/tls/truststore.pem') }}"
    .. note::
       The ``common`` role comes with ability to set-up time
       synchronisation using NTP. This is not done by default. For
       details see the role parameter ``ntp_servers``.
    .. note::
       The ``ca_certificates`` parameter lets us deploy custom CA
       certificates on servers. The name we pick (in this case
       ``truststore``) can be set to anything. In this particular case,
       we want to deploy our own CA certificate for use as truststore,
       since this is what the services will use to validate server
       certificates when connecting to each-other.
 . That's all for configuration, time to apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . After this you should be able to *ssh* from Ansible server onto the
    managed servers as user ``admin`` using the *SSH* private key of
    the ``ansible`` user on controller machine. The ``admin`` user's
    password has also been set to ``admin``, and the user will be
    member of ``sudo`` group.
    .. note::
       Remote logins over SSH using password authentication are
       explicitly disabled as part of common set-up/hardening.
 Introducing LDAP
 ----------------
 Since some of the services actually depend on LDAP, we'll go ahead and set that
 one up first. This includes both the LDAP *server* and *client* configuration.
 . Update the playbook for communications server to include the LDAP client and
    server roles (``ldap_client`` and ``ldap_server``, respectively).
    :file:`~/mysite/playbooks/communications.yml`
    ::
       ---
       - hosts: communications
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - ldap_server
 . Update the playbook for web server to include the LDAP client role
    (``ldap_client``). You never know when it might come in handy :)
    :file:`~/mysite/playbooks/web.yml`
    ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
 . Time to configure the roles. For start, let us configure the LDAP
    server role. Keep in mind that there is a lot of default variables
    set-up by the role itself, making our config rather short. The
    ``ldap_server_domain`` parameter will be used to form the base DN
    of the LDAP directory (resulting in ``dc=example,dc=com``).
    :file:`~/mysite/group_vars/communications.yml`
    ::
       ---
       ldap_admin_password: admin
       ldap_server_domain: example.com
       ldap_server_organization: "Example Inc."
       ldap_server_tls_certificate: "{{ lookup('file', '~/mysite/tls/comms.example.com_ldap.pem') }}"
       ldap_server_tls_key: "{{ lookup('file', '~/mysite/tls/comms.example.com_ldap.key') }}"
 . Phew. That was... Well, actually, easy :) Technically, only the
    LDAP admin password, domain, and TLS certificate/key *must* be set,
    but it is nice to have organisation explicitly specified as well
    (instead of using whatever Debian picks as default). Let us add the
    LDAP client configuration next. We will start off with global LDAP
    client configuration. In case of the LDAP client role, we have got
    to be a bit more explicit.
    :file:`~/mysite/group_vars/all.yml`
    ::
       # Observe how we set the base DN. By default the ldap_server role
       # (defined up there) will use server's domain to form the base for LDAP.
       ldap_client_config:
         - comment: Set the base DN
           option: BASE
           value: dc=example,dc=com
         - comment: Set the default URI
           option: URI
           value: ldap://comms.example.com/
         - comment: Set the LDAP TLS truststore
           option: TLS_CACERT
           value: /etc/ssl/certs/truststore.pem
         - comment: Enforce TLS
           option: TLS_REQCERT
           value: demand
 . Ok, so this looks nice and dandy... But, let's have a bit better
    configuration on the communications server itself. Namely, on that
    one we should be able to connect to the LDAP server via unix socket
    instead of TCP.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       ldap_client_config:
         - comment: Set the base DN
           option: BASE
           value: dc=example,dc=com
         - comment: Set the default URI
           option: URI
           value: ldapi:///
         - comment: Set the default bind DN, useful for administration.
           option: BINDDN
           value: cn=admin,dc=example,dc=com
         - comment: Set the LDAP TLS truststore
           option: TLS_CACERT
           value: /etc/ssl/certs/truststore.pem
         - comment: Enforce TLS
           option: TLS_REQCERT
           value: demand
 . Ok, time to re-run the playbooks again... Wait a minute, something
    is missing here... Ah, right, we have to generate the TLS private
    key and issue the X.509 certificate.
 . Create template for the ``certtool`` so it would know what
       extensions and content to have in the certificate:
       :file:`~/mysite/tls/comms.example.com_ldap.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. LDAP Server"
          expiration_days = 365
          dns_name = "comms.example.com"
          tls_www_server
          signing_key
          encryption_key
 . Almost there... Now let us generate the key and issue the certificate::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/comms.example.com_ldap.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/comms.example.com_ldap.cfg --load-privkey ~/mysite/tls/comms.example.com_ldap.key --outfile ~/mysite/tls/comms.example.com_ldap.pem
 . And now, for the finishing touch, just run the playbooks again::
      workon mysite && ansible-playbook playbooks/site.yml
 Adding mail server
 ------------------
 The next thing in line is to implement the mail server capability. *Majic
 Ansible Roles* come with two distinct mail server-related roles. One for
 setting-up a mail server host (with authenticated IMAP, SMTP, mail storage etc),
 and one for setting-up a local SMTP mail forwarder (for having the rest of your
 servers relay their mails to the mail server host).
 .. note::
    Should you ever need to deploy the forwarder role on a laptop or
    machine behind NAT, make sure to look at the
    ``smtp_from_relay_allowed`` parameter. In case you need to connect
    to the SMTP relay via non-standard port (for example to work-around
    ISP blocks), have a look at the ``smtp_relay_host_port`` parameter.
 The mail server role looks-up available mail domains, users, and aliases in the
 LDAP directory. This has already been set-up on the server
 ``comms.example.com``, but some changes will be required.
 . Update the playbook for communications server to include the mail server
 role.
     :file:`~/mysite/playbooks/communications.yml`
     ::
       ---
       - hosts: communications
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - ldap_server
           - mail_server
 . Let's configure the role next.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       # Set the LDAP URL to connect through. Keep in mind TLS is required.
       mail_ldap_url: ldap://comms.example.com/
       # Here we need to point to the base DN of LDAP server. A bunch of entries
       # will need to exist under it for service to function correctly, though.
       mail_ldap_base_dn: dc=example,dc=com
       # Separate LDAP entries are used for Postfix/Dovecot
       # authentication. Therefore we have two passwords here.
       mail_ldap_postfix_password: postfix
       mail_ldap_dovecot_password: dovecot
       # Setting uid/gid is optional, but you might have a policy on how to
       # assign UIDs and GIDs, so it is convenient to be able to change this.
       mail_user_uid: 5000
       mail_user_gid: 5000
       # Set private keys and certificates to use for the IMAP service.
       imap_tls_certificate: "{{ lookup('file', '~/mysite/tls/comms.example.com_imap.pem') }}"
       imap_tls_key: "{{ lookup('file', '~/mysite/tls/comms.example.com_imap.key') }}"
       # Set private keys and certificates to use for the SMTP service.
       smtp_tls_certificate: "{{ lookup('file', '~/mysite/tls/comms.example.com_smtp.pem') }}"
       smtp_tls_key: "{{ lookup('file', '~/mysite/tls/comms.example.com_smtp.key') }}"
       # Set the X.509 certificate truststore to use for validating the
       # LDAP server certificate.
       mail_ldap_tls_truststore: "{{ lookup('file', '~/mysite/tls/truststore.pem') }}"
 . There are two distinct mail services that need to access the LDAP directory -
    *Postfix* (serving as an SMTP server), and *Dovecot* (serving as an IMAP
    server). These two need their own dedicated LDAP entries on the LDAP server in
    order to log-in. Luckily, it is easy to create such entries through the options
    provided by the LDAP server role. In addition to this, the Postfix and Dovecot
    services will check if users are members of ``mail`` group in LDAP directory
    before accepting them as valid mail users. Once again, the LDAP server role
    comes with a simple option for creating groups.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       # Don't forget, the passwords here must match with passwords specified
       # under options mail_ldap_postfix_password/mail_ldap_dovecot_password.
       ldap_server_consumers:
         - name: postfix
           password: postfix
         - name: dovecot
           password: dovecot
       ldap_server_groups:
         - name: mail
 . Ok, so now our SMTP and IMAP service can log-in into the LDAP server to
    look-up the mail server information. We have also defined the mail group for
    limitting which users get mail service. However, we don't have any
    user/domain information yet. So let's change that, using the ``ldap_entries``
    option from LDAP server role.
    .. warning::
       Long-term, you probably want to manage these entries manually or through
       other means than the ``ldap_entries`` option. The reason for this is
       because this type of data in LDAP directory can be considered more of an
       operational/application data than configuration data that frequently
       changes (especially the user passwords/info). Backups of LDAP directory on
       regular basis are important. We will get to that at a later point.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       ldap_entries:
         # Create first a couple of user entries. Don't forget to set the
         # "mail" attribute for them.
         - dn: uid=johndoe,ou=people,dc=example,dc=com
           attributes:
             objectClass:
               - inetOrgPerson
             uid: johndoe
             cn: John Doe
             sn: Doe
             userPassword: johndoe
             mail: john.doe@example.com
         - dn: uid=janedoe,ou=people,dc=example,dc=com
           attributes:
             objectClass:
               - inetOrgPerson
             uid: janedoe
             cn: Jane Doe
             sn: Doe
             userPassword: janedoe
             mail: jane.doe@example.com
         # Let's register our domain in LDAP directory.
         - dn: dc=example.com,ou=domains,ou=mail,ou=services,dc=example,dc=com
           attributes:
             objectClass: dNSDomain
             dc: "example.com"
           # Finally, for the lolz, let's also add the standard postmaster alias
           # for our domain. This one will also receive any undeliverable bounced
           # mails.
         - dn: cn=postmaster@example.com,ou=aliases,ou=mail,ou=services,dc=example,dc=com
           attributes:
             objectClass: nisMailAlias
             cn: postmaster@example.com
             rfc822MailMember: john.doe@example.com
 . Once again, before we apply the configuration, we must make sure the
    necessary TLS private keys and certificates are available. In this particular
    case, we need to set-up separate key/certificate pair for both the SMTP and
    IMAP service:
 . Create new templates for ``certtool``:
       :file:`~/mysite/tls/comms.example.com_smtp.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. SMTP Server"
          expiration_days = 365
          dns_name = "comms.example.com"
          tls_www_server
          signing_key
          encryption_key
       :file:`~/mysite/tls/comms.example.com_imap.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. IMAP Server"
          expiration_days = 365
          dns_name = "comms.example.com"
          tls_www_server
          signing_key
          encryption_key
 . Create the keys and certificates for SMTP/IMAP services based on the templates::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/comms.example.com_smtp.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/comms.example.com_smtp.cfg --load-privkey ~/mysite/tls/comms.example.com_smtp.key --outfile ~/mysite/tls/comms.example.com_smtp.pem
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/comms.example.com_imap.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/comms.example.com_imap.cfg --load-privkey ~/mysite/tls/comms.example.com_imap.key --outfile ~/mysite/tls/comms.example.com_imap.pem
 . Configuration and TLS keys have ben set-up, so it is time to apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . Let's add the two users to the mail group (otherwise, the mail
    server will ignore them). We'll use the ``ldap_attr`` module
    directly to make our life a bit easier::
      workon mysite && ansible --become -m ldap_attr -a "dn=cn=mail,ou=groups,dc=example,dc=com state=present name=uniqueMember values=uid=johndoe,ou=people,dc=example,dc=com" communications
      workon mysite && ansible --become -m ldap_attr -a "dn=cn=mail,ou=groups,dc=example,dc=com state=present name=uniqueMember values=uid=janedoe,ou=people,dc=example,dc=com" communications
 . If no errors have been reported, at this point you should have two mail
    accounts - ``john.doe@example.com``, with password ``johndoe``, and
    ``jane.doe@example.com``, with password ``janedoe``. In this particular
    set-up, the mail addresses are used as usernames. If you want to test it out,
    simply install ``swaks`` on your Ansible machine, and run something along the
    lines of
    ::
      swaks --to john.doe@example.com --server comms.example.com
      swaks --to jane.doe@example.com --server comms.example.com
   Of course, free feel to also test out the mail server using any mail client of
   your choice. When doing so, use port 587 for SMTP. Port 25 is reserved for
   unauthenticated server-to-server mail deliveries.
   If you face issues with ISPs or hotels blocking the two ports listed above,
   you can also use alternative ports 26 (redirected to port 587) and 27
   (redirected to port 25).
   TLS has also been hardened on port 587 to allow only TLSv1.2 and PFS ciphers
   (you can override TLS versions/ciphers via role configuration). TLS
   configuration on port 25 has been left unchanged for maximum
   interoperability with other servers.
 Setting-up mail relaying from web and backup servers
 ----------------------------------------------------
 With the mail server set-up, the next thing to do would be to set-up the SMTP
 server on web and backup servers to relay mails via the communications
 server. This way we can make sure that mail that gets sent via local SMTP to
 external addresses on those two servers goes through our anti-virus scanner.
 . Update the list of roles for web and backup server to include the mail
    forwarder role.
    :file:`~/mysite/playbooks/web.yml`
    ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - mail_forwarder
    :file:`~/mysite/playbooks/backup.yml`
    ::
       ---
       - hosts: backup
         remote_user: ansible
         become: yes
         roles:
           - common
           - mail_forwarder
 . The next thing is to set-up the configuration for the new role. We can define
    this globally for all servers
    :file:`~/mysite/group_vars/all.yml`
    ::
       # Define what X.509 certificates should be used for validating
       # the certificate of server we are relaying the mails through.
       smtp_relay_truststore: "{{ lookup('file', '~/mysite/tls/truststore.pem') }}"
       # Make sure any mails directed to localhost root account get
       # forwarded to one of our mail users as well.
       local_mail_aliases:
         root: root john.doe@example.com
       # Now signal the local SMTP to relay any non-local mails via our
       # communications server. Don't forget to specify your own IP address (or
       # FQDN) here. Without this option, the SMTP would send out the mails
       # directly.
       smtp_relay_host: comms.example.com
 . Although we have told our web and backup servers to use the communications
    server as relay for non-local mail, the communications server is not aware of
    this. This would result in the communications server refusing all relay
    attempts (if not, it would be an open relay, which is bad).
    So, let's fix this a bit - we have a configuration option for the mail server
    for exactly this purpose.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       # We want to allow relaying of mails from our web and backup servers
       # here.Beware the IP spoofing, though! Don't forget to change the bellow
       # IP for your server ;)
       smtp_allow_relay_from:
         - 10.32.64.20
         - 10.32.64.23
 . Let's apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . After this you may want to test out sending mail via web or backup server's
    local SMTP to the root user (to see if the aliasing works), and to some
    external mail address to check if forwarding works correctly too. Run
    something similar to the following on your web server::
      swaks --to root@localhost --server localhost
      swaks --to YOUR_MAIL --server localhost
    If all went well, you should be able to see a new mail in John Doe's mailbox,
    as well as your own mailbox.
 Adding XMPP server
 ------------------
 Now that the users can communicate via mail server, we might as well add support
 for some instant messaging. For this purpose, we will use the ``xmpp_server``
 role.
 . Update the playbook for communications server to include the XMPP server
    role.
    :file:`~/mysite/playbooks/communications.yml`
    ::
       ---
       - hosts: communications
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - ldap_server
           - mail_server
           - xmpp_server
 . Configure the role.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       # Set the TLS private key and certificate.
       xmpp_tls_certificate: "{{ lookup('file', '~/mysite/tls/comms.example.com_xmpp.pem') }}"
       xmpp_tls_key: "{{ lookup('file', '~/mysite/tls/comms.example.com_xmpp.key') }}"
       # Set one of the users to also be an XMPP administrator.
       xmpp_administrators:
         - john.doe@example.com
       # Unfortunately, XMPP can't look-up domains via LDAP, so we need to be
       # explicit here.
       xmpp_domains:
         - example.com
       # Simply point the XMPP server to base DN of LDAP server, and let it use
       # specific directory structure it expects.
       xmpp_ldap_base_dn: dc=example,dc=com
       # Password for logging-in into the LDAP directory.
       xmpp_ldap_password: prosody
       # Where the LDAP server is located at. Full-blown LDAP URIs are _not_
       # supported!
       xmpp_ldap_server: comms.example.com
 . Now, like in case of the mail server role, we need to set-up authentication
    for the XMPP service. In this particular case a single consumer is present -
    Prosody itself. We should also create the group for granting the users right
    to use the service.
    :file:`~/mysite/group_vars/communications.yml`
    ::
       # Just make sure the new entry is added for the prosody user - you can
       # leave the postfix/dovecot intact in your file if you use different
       # passwords. Keep in mind password for prosody user must match with
       # password specified under xmpp_ldap_password.
       ldap_server_consumers:
         - name: postfix
           password: postfix
         - name: dovecot
           password: dovecot
         - name: prosody
           password: prosody
       # And simply append a new group here...
       ldap_server_groups:
         - name: mail
         - name: xmpp
 . Do you know what comes next? Yes! Create some more TLS private keys
    and certificates, this time for our XMPP server ;)
 . Create new template for ``certtool``:
       :file:`~/mysite/tls/comms.example.com_xmpp.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. XMPP Server"
          expiration_days = 365
          dns_name = "example.com"
          tls_www_server
          signing_key
          encryption_key
 . Create the keys and certificates for XMPP service based on the template::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/comms.example.com_xmpp.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/comms.example.com_xmpp.cfg --load-privkey ~/mysite/tls/comms.example.com_xmpp.key --outfile ~/mysite/tls/comms.example.com_xmpp.pem
 . Apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . Ok, configuration of the role is complete. You may have noticed
    that we still haven't added any users to the new LDAP group called
    "xmpp". So let us correct this in similar way as we did for the
    mail server. Since we have the user entries already, no need to
    recreate them here. We will just update the group membership
    instead.
    .. warning::
       Same warning applies here as for mail server role for managing the
       user/group entries! Scroll up and re-read it if you missed it!
    ::
       workon mysite && ansible --become -m ldap_attr -a "dn=cn=xmpp,ou=groups,dc=example,dc=com state=present name=uniqueMember values=uid=johndoe,ou=people,dc=example,dc=com" communications
       workon mysite && ansible --become -m ldap_attr -a "dn=cn=xmpp,ou=groups,dc=example,dc=com state=present name=uniqueMember values=uid=janedoe,ou=people,dc=example,dc=com" communications
 . If no errors have been reported, at this point you should have two users
    capable of using the XMPP service - one with username
    ``john.doe@example.com`` and one with username ``jane.doe@example.com``. Same
    passwords are used as for when you were creating the two users for mail
    server. For testing you can turn to your favourite XMPP client (I don't know
    of any quick CLI-based tools to test the XMPP server functionality,
    unfortunately, but you could try using `mcabber <https://mcabber.com/>`_).
 Taking a step back - preparing for web server
 ---------------------------------------------
 Up until now the usage instructions have dealt almost exclusively with the
 communications server. That is, we haven't done anything beyond the basic set-up
 of the other servers.
 Let us first define what we want to deploy on the web server. Here is the plan:
 . First off, we will set-up the web server. This will be necessary no matter
    what web application we decide to deploy later on.
 . Next, we will set-up a database server. Why? Well, most web applications
    need to use some sort of database to store all the data, so we might as well
    try to take that one out of the way.
 . With this basic deployment for a web server in place, we can move on to
    setting-up a couple of web applications. For the purpose of the usage
    instructions, we will deploy the following two:
 . `The Bug Genie <http://thebuggenie.org/>`_ - an issue tracker. To keep
       things simple, we will not integrate it with our LDAP server (although
       this is supported and possible). Being written in PHP, this will
       demonstrate the role for PHP web application deployment.
 . `Django Wiki <https://github.com/django-wiki/django-wiki>`_ - a wiki
       application written in Django. This will serve as a demo of how the WSGI
       role works.
 It should be noted that the web application deployment roles are a bit more
 complex - namely they are not meant to be used directly, but instead as a
 dependency for a custom role. They do come with decent amount of batteries
 included, and also play nice with the web server role.
 As mentioned before, all roles will enforce TLS by default. The web server roles
 will additionaly implement HSTS policy by sending connecting clients
 ``Strict-Transport-Security`` header with value set to ``max-age=31536000;
 includeSubDomains``.
 With all the above noted, let us finally move on to the next step.
 Setting-up the web server
 -------------------------
 Finally we are moving on to the web server deployment, and we shell start
 with... Well, erm, web server deployment! To be more precise, we will set-up
 Nginx.
 . Update the playbook for web server to include the web server role.
     :file:`~/mysite/playbooks/web.yml`
     ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - mail_forwarder
           - web_server
 . You know the drill, role configuration comes up next. No
    configuration has been deployed before for the web server, so we
    will be creating a new file. Only the TLS parameters are really
    necessary, but we'll spice things up a bit by setting custom title
    and message for default virtual host.
    :file:`~/mysite/group_vars/web.yml`
    ::
       ---
       default_https_tls_certificate: "{{ lookup('file', '~/mysite/tls/www.example.com_https.pem') }}"
       default_https_tls_key: "{{ lookup('file', '~/mysite/tls/www.example.com_https.key') }}"
       web_default_title: "Welcome to default page!"
       web_default_message: "Nothing to see here, move along..."
 . The only thing left now is to create the TLS private key/certificate pair
    that should be used for default virtual host.
 . Create new template for ``certtool``:
       :file:`~/mysite/tls/www.example.com_https.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. Web Server"
          expiration_days = 365
          dns_name = "www.example.com"
          tls_www_server
          signing_key
          encryption_key
 . Create the keys and certificates for default web server virtual host based
       on the template::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/www.example.com_https.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/www.example.com_https.cfg --load-privkey ~/mysite/tls/www.example.com_https.key --outfile ~/mysite/tls/www.example.com_https.pem
 . Apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . If no errors have been reported, at this point you should have a default web
    page available and visible at https://www.example.com/ . By default plaintext
    connections are disabled, and trying to visit http://www.example.com/ should
    simply redirect you to the HTTPS address. Feel free to try it out with some
    browser. Keep in mind you will get a warning about the untrusted certificate!
 Adding the database server
 --------------------------
 Since both of the web applications we want to deploy need a database, we will
 proceed to set-up the database server role on the web server itself. *Majic
 Ansible Roles* in particular come with a role that will deploy MariaDB database
 server.
 .. note::
    The ``database_server`` role will set-up unix socket authentication
    for the database ``root`` user. I.e. the ``root`` database user
    will have no password set, but authentication will pass only when
    logging-in as the operating system ``root`` user while connecting
    over database server unix socket.
 . Update the playbook for web server to include the database server role.
     :file:`~/mysite/playbooks/web.yml`
     ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - mail_forwarder
           - web_server
           - database_server
 . This particular role has no parameters, and no additional steps are
    necessary to configure it. So move along...
 . No TLS support has been implemented for this role (yet), so simply apply the
    changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . If no errors have been reported, you should have a database server up and
    running on the web server. You should be able to log-in as ``root``
    operating system user by running the following command on the web
    server itself::
      mysql
    Of course, no database has been created for either of the web applications,
    but we will get to that one later (there is a dedicated ``database`` role
    which can be combined with web app roles for this purpose).
 Deploying a PHP web application (The Bug Genie)
 -----------------------------------------------
 We have some basic infrastructure up and running on our web server, so
 now we can move on to setting-up a PHP web application on it. As
 mentioned before, we will take *The Bug Genie* as an example.
 For this we will create a local role in our site to take care of it. This role
 will in turn utilise two roles coming from *Majic Ansible Roles* that will make
 our life (a little) easier.
 To make the example a bit simpler, no parameters will be introduced
 for this role (not even the password for database, we'll hard-code
 everything).
 Before we start, here is a couple of useful pointers regarding the
 ``php_website`` role we'll be using for the PHP part:
 * The role is designed to execute every application via dedicated user and
   group. The user/group name is automatically derived from the FQDN of website,
   for example ``web-tbg_example_com``.
 * While running the application, application user's umask is set to ``0007``
   (letting the administrator user be able to manage any files created while the
   application is running).
 * An administrative user is created as well, and this user should be used when
   running maintenance and installation commands. Similar to application user,
   the name is also derived from the FQDN of website, for example
   ``admin-tbg_example_com``. Administrative user does not have a dedicated
   group, and instead belongs to same group as the application user.
 * PHP applications are executed via FastCGI, using *PHP-FPM*.
 * If you ever need to set some additional PHP FPM settings, this can easily be
   done via the ``additional_fpm_config`` role parameter. This particular example
   does not set any, though.
 * Mails delivered to local admin/application users are forwarded to ``root``
   account instead (this can be configured via ``website_mail_recipients`` role
   parameter.
 * If you ever find yourself mixing-up test and production websites,
   have a look at ``environment_indicator`` role parameter. It lets you
   insert small strip with environment information at bottom of each
   HTML page served by the web server.
 * Static content (non-PHP) is served directly by *Nginx*.
 * Each web application gets distinct sub-directory under ``/var/www``, named
   after the FQDN. All sub-directories created under there are created with
   ``02750`` permissions, with ownership set to admin user, and group set to the
   application's group. In other words, all directories will have ``SGID`` bit
   set, allowing you to create files/directories that will have their group
   automatically set to the group of the parent directory.
 * Files are served (both by *Nginx* and *PHP-FPM*) from sub-directory called
   ``htdocs`` (located in website directory). For example
   ``/var/www/tbg.example.com/htdocs/``. Normally, this can be a symlink to some
   other sub-directory within the website directory (useful for having multiple
   versions for easier downgrades etc).
 * Combination of admin user membership in application group, ``SGID``
   permission, and the way ownership of sub-directories is set-up usually means
   that the administrator will be capable of managing application files, and
   application can be granted write permissions to a *minimum* of necessary
   files.
   .. warning::
      Just keep in mind that some file-management commands, like ``mv``, do *not*
      respect the ``SGID`` bit. In fact, I would recommend using ``cp`` when you
      deploy new files to the directory instead (don't simply move them from your
      home directory).
 . Start-off with creating the necessary directories for the new role::
      mkdir -p ~/mysite/roles/tbg/{tasks,meta,files}/
 . Let's set-up role dependencies, reusing some common roles to make our life
    easier.
    :file:`~/mysite/roles/tbg/meta/main.yml`
    ::
       ---
       dependencies:
         # Ok, so this role helps us set-up Nginx virtual host for serving our
         # app.
         - role: php_website
           # Our virtual host will for PHP website will respond to this name.
           fqdn: tbg.example.com
           # TLS key and certificate to use for the virtual host.
           https_tls_certificate: "{{ lookup('file', '~/mysite/tls/tbg.example.com_https.pem') }}"
           https_tls_key: "{{ lookup('file', '~/mysite/tls/tbg.example.com_https.key') }}"
           # Some additional packages are required in order to deploy and use TBG.
           packages:
             - php-gd
             - php-curl
             - php-mbstring
             - php-xml
             - git
             - php-mysql
             - php-apcu
             - php-zip
           # Set-up URL rewriting. This is based on public/.htaccess file from
           # TBG.
           php_rewrite_urls:
             - ^(.*)$ /index.php?url=$1
           # We don't necessarily need this, but in case you have a policy on
           # uid/gid usage, this is useful. Take note that below value is used
           # for both the dedicated uid and gid for application user.
           uid: 2000
           admin_uid: 3000
         # And this role sets up a new dedicated database for our web
         # application.
         - role: database
           # This is both the database name, _and_ name of the database user
           # that will be granted full privileges on the database.
           db_name: tbg
           # This will be the password of our user 'tbg' for accessing the
           # database. Take note the user can only login from localhost.
           db_password: tbg
 . Now for my favourite part again - creating private keys and certificates!
    Why?  Because the ``php_website`` role requires a private key/certificate
    pair to be deployed. So... Moving on:
 . Create new template for ``certtool``:
       :file:`~/mysite/tls/tbg.example.com_https.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. Issue Tracker"
          expiration_days = 365
          dns_name = "tbg.example.com"
          tls_www_server
          signing_key
          encryption_key
 . Create the keys and certificates for the application::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/tbg.example.com_https.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/tbg.example.com_https.cfg --load-privkey ~/mysite/tls/tbg.example.com_https.key --outfile ~/mysite/tls/tbg.example.com_https.pem
 . Time to get our hands a bit more dirty... Up until now we didn't have to write
    custom tasks, but at this point we need to.
    :file:`~/mysite/roles/tbg/tasks/main.yml`
    ::
       ---
       - name: Define TBG version
         set_fact:
           tbg_version: "4.3.1"
           tbg_archive_checksum: "45de72b1ef82142ad46686577d593375ba370156df4367d17386b4e26a37f342"
       - name: Download the TBG archive
         get_url:
           url: "https://github.com/thebuggenie/thebuggenie/archive/v{{ tbg_version }}.tar.gz"
           dest: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}.tar.gz"
           sha256sum: "{{ tbg_archive_checksum }}"
         become: yes
         become_user: admin-tbg_example_com
       - name: Download Composer
         get_url:
           url: "https://getcomposer.org/download/1.10.19/composer.phar"
           dest: "/usr/local/bin/composer"
           sha256sum: "688bf8f868643b420dded326614fcdf969572ac8ad7fbbb92c28a631157d39e8"
           owner: root
           group: root
           mode: 0755
       - name: Unpack TBG
         unarchive:
           src: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}.tar.gz"
           dest: "/var/www/tbg.example.com/"
           copy: no
           creates: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}"
         become: yes
         become_user: admin-tbg_example_com
       - name: Allow use of lib-pcre version 10 (since PHP is built against it in Debian Buster)
         lineinfile:
           dest: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/{{ item }}"
           state: present
           regexp: '.*"lib-pcre".*'
           line: '        "lib-pcre": ">=8.0",'
         with_items:
           - "composer.json"
           - "composer.lock"
       - name: Create directory for storing uploaded files
         file:
           path: "/var/www/tbg.example.com/files"
           state: directory
           mode: 02770
         become: yes
         become_user: admin-tbg_example_com
       - name: Create symlink towards directory where uploaded files are stored
         file:
           src: "/var/www/tbg.example.com/files"
           dest: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/files"
           state: link
         become: yes
         become_user: admin-tbg_example_com
       - name: Create TBG cache directory
         file:
           path: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/cache"
           state: directory
           mode: 02770
         become: yes
         become_user: admin-tbg_example_com
       - name: Set-up the necessary write permissions for TBG directories
         file:
           path: "{{ item }}"
           mode: g+w
         with_items:
           - /var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/
           - /var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/public/
           - /var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/core/config/
       - name: Create symbolic link to TBG application
         file:
           src: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/public"
           path: "/var/www/tbg.example.com/htdocs"
           state: link
           owner: "admin-tbg_example_com"
           group: "web-tbg_example_com"
         become: yes
         become_user: admin-tbg_example_com
       - name: Install TBG dependencies
         composer:
           command: install
           working_dir: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}"
         become: yes
         become_user: admin-tbg_example_com
       - name: Deploy database configuration file for TBG
         copy:
           src: "b2db.yml"
           dest: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/core/config/b2db.yml"
           mode: 0640
           owner: admin-tbg_example_com
           group: web-tbg_example_com
       - name: Install pexpect package
         apt:
           name: python3-pexpect
           state: present
       - name: Deploy expect script for installing TBG
         copy:
           src: "tbg_expect_install"
           dest: "/var/www/tbg.example.com/tbg_expect_install"
           mode: 0750
           owner: admin-tbg_example_com
           group: web-tbg_example_com
       - name: Run TBG installer via expect script
         command: /var/www/tbg.example.com/tbg_expect_install
         args:
           chdir: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}"
           creates: "/var/www/tbg.example.com/thebuggenie-{{ tbg_version }}/installed"
         become: yes
         become_user: admin-tbg_example_com
 . Set-up the files that are deployed by our role.
    :file:`~/mysite/roles/tbg/files/b2db.yml`
    ::
       b2db:
           username: "tbg"
           password: "tbg"
           dsn: "mysql:host=localhost;dbname=tbg"
           tableprefix: ''
           cacheclass: '\thebuggenie\core\framework\Cache'
    :file:`~/mysite/roles/tbg/files/tbg_expect_install`
    ::
       #!/usr/bin/env python3
       import pexpect
       # Spawn the process.
       install_process = pexpect.spawnu('./tbg_cli', args = ["install",
                                                                         "--accept_license=yes",
                                                                         "--url_subdir=/",
                                                                         "--use_existing_db_info=yes",
                                                                         "--enable_all_modules=no",
                                                                         "--setup_htaccess=yes"])
       # If we get EOF, we probably already installed application, and ran
       # into error at the end since no patterns matched.
       try:
           # First confirmation.
           install_process.expect(u'Press ENTER to continue with the installation: ', timeout=5)
           install_process.sendline(u'')
           # Second confirmation.
           install_process.expect(u'Press ENTER to continue: ', timeout=5)
           install_process.sendline(u'')
           # Wait for application to finish.
           install_process.expect(pexpect.EOF, timeout=60)
       except pexpect.EOF as e:
           pass
       # Close application.
       install_process.close()
       # Print text output.
       print(install_process.before)
       # Return same exit code like child process.
       exit(install_process.exitstatus)
 . And... Let's add the new role to our web server.
    :file:`~/mysite/playbooks/web.yml`
    ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - mail_forwarder
           - web_server
           - database_server
           - tbg
 . Apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . At this point *The Bug Genie* has been installed, and you should be able to
    open the URL https://tbg.example.com/ and log-in into *The Bug Genie*
    with username ``administrator`` and password ``admin``.
 Deploying a WSGI application (Django Wiki)
 ------------------------------------------
 Next thing up will be to deploy a WSGI Python application.
 Similar to the PHP application deployment, we will use a couple of roles to make
 it easier to deploy it in a standardised manner, and we will not have any kind
 of parameters for configuring the role to keep things simple.
 Most of the notes on how a ``php_website`` role is deployed also stand for the
 ``wsgi_website`` role, but we will reiterate and clarify them a bit just to be
 on the safe side:
 * The role is designed to execute every application via dedicated user and
   group. The user/group name is automatically derived from the FQDN of website,
   for example ``web-wiki_example_com``.
 * While running the application, application user's umask is set to ``0007``
   (letting the administrator user be able to manage any files created while the
   application is running).
 * An administrative user is created as well, and this user should be used when
   running maintenance and installation commands. Similar to application user,
   the name is also derived from the FQDN of website, for example
   ``admin-wiki_example_com``. Administrative user does not have a dedicated
   group, and instead belongs to same group as the application user. As
   convenience, whenever you switch to this user the Python virtual environment
   will be automatically activated for you.
 * WSGI applications are executed via *Gunicorn*. The WSGI server listens on a
   Unix socket, making the socket accessible by *Nginx*.
 * If you ever need to set some environment variables, this can easily be done
   via the ``environment_variables`` role parameter. This particular example does
   not set any, though.
 * You can also specify headers to be passed on via Nginx ``proxy_set_header``
   directive to Gunicorn running the application.
 * Mails deliverd to local admin/application users are forwarded to ``root``
   account instead (this can be configured via ``website_mail_recipients`` role
   parameter.
 * If you ever find yourself mixing-up test and production websites,
   have a look at ``environment_indicator`` role parameter. It lets you
   insert small strip with environment information at bottom of each
   HTML page served by the web server.
 * Static content is served directly by *Nginx*.
 * Each web application gets distinct sub-directory under ``/var/www``, named
   after the FQDN. All sub-directories created under there are created with
   ``2750`` permissions, with ownership set to admin user, and group set to the
   application's group. In other words, all directories will have ``SGID`` bit
   set, allowing you to create files/directories that will have their group
   automatically set to the group of the parent directory.
 * Each WSGI website gets a dedicated virtual environment, stored in the
   sub-directory ``virtualenv`` of the website directory, for example
   ``/var/www/wiki.example.com/virtualenv``.
 * Static files are served from sub-directory ``htdocs`` in the website
   directory, for example ``/var/www/wiki.example.com/htdocs/``.
 * The base directory where your website/application code should be at is
   expected to be in sub-directory ``code`` in the website directory, for example
   ``/var/www/wiki.example.com/code/``.
 * Combination of admin user membership in application group, ``SGID``
   permission, and the way ownership of sub-directories is set-up usually means
   that the administrator will be capable of managing application files, and
   application can be granted write permissions to a *minimum* of necessary
   files.
   .. warning::
      Just keep in mind that some file-management commands, like ``mv``, do *not*
      respect the ``SGID`` bit. In fact, I would recommend using ``cp`` when you
      deploy new files to the directory instead (don't simply move them from your
      home directory).
 . Set-up the necessary directories first::
      mkdir -p ~/mysite/roles/wiki/{tasks,meta,files,handlers}/
 . Set-up some role dependencies, reusing the common role infrastructure.
    :file:`~/mysite/roles/wiki/meta/main.yml`
    ::
       ---
       dependencies:
         - role: wsgi_website
           fqdn: wiki.example.com
           # TLS key and certificate to use for the virtual host.
           https_tls_certificate: "{{ lookup('file', '~/mysite/tls/wiki.example.com_https.pem') }}"
           https_tls_key: "{{ lookup('file', '~/mysite/tls/wiki.example.com_https.key') }}"
           # In many cases you need to have some development packages available
           # in order to build Python packages installed via pip
           packages:
             - build-essential
             - python3-dev
             - libjpeg62-turbo
             - libjpeg-dev
             - libpng16-16
             - libpng-dev
             - libmariadb-dev
             - libmariadb-dev-compat
           # Specify that Python 3 should be used for the application
           python_version: 3
           # Here we specify that anything accessing our website with "/static/"
           # URL should be treated as request to a static file, to be served
           # directly by Nginx instead of the WSGI server.
           static_locations:
             - /static/
           # Again, not mandatory, but it is good to have some sort of policy
           # for assigning UIDs.
           uid: 2001
           admin_uid: 3001
           # These are additional packages that should be installed in the
           # virtual environment.
           virtualenv_packages:
             - django~=2.2.0
             - wiki~=0.5.0
             - mysqlclient
           # This is the name of the WSGI application to
           # serve. wiki_example_com.wsgi will be the Python "module" that is
           # accesed, while application is the object instantiated within it (the
           # application itself). The module is referenced relative to the code
           # directory (in our case /var/www/wiki.example.com/code/).
           wsgi_application: wiki_example_com.wsgi:application
           # Specify explicitly requirements for installing Gunicorn.
           wsgi_requirements:
             - gunicorn==20.0.4
           wsgi_requirements_in:
             - gunicorn
         - role: database
           db_name: wiki
           db_password: wiki
 . Let's create a dedicated private key/certificate pair for the wiki website:
 . Create new template for ``certtool``:
       :file:`~/mysite/tls/wiki.example.com_https.cfg`
       ::
          organization = "Example Inc."
          country = SE
          cn = "Exampe Inc. Wiki"
          expiration_days = 365
          dns_name = "wiki.example.com"
          tls_www_server
          signing_key
          encryption_key
 . Create the keys and certificates for the application::
         certtool --sec-param normal --generate-privkey --outfile ~/mysite/tls/wiki.example.com_https.key
         certtool --generate-certificate --load-ca-privkey ~/mysite/tls/ca.key --load-ca-certificate ~/mysite/tls/ca.pem --template ~/mysite/tls/wiki.example.com_https.cfg --load-privkey ~/mysite/tls/wiki.example.com_https.key --outfile ~/mysite/tls/wiki.example.com_https.pem
 . At this point we have exhausted what we can do with the built-in roles. Time
    to add some custom tasks.
    :file:`~/mysite/roles/wiki/tasks/main.yml`
    ::
       ---
       - name: Create Django project directory
         file:
           dest: "/var/www/wiki.example.com/code"
           state: directory
           owner: admin-wiki_example_com
           group: web-wiki_example_com
           mode: 02750
       - name: Start Django project for the Wiki website
         command: "/var/www/wiki.example.com/virtualenv/bin/exec django-admin.py startproject wiki_example_com /var/www/wiki.example.com/code"
         args:
           chdir: "/var/www/wiki.example.com"
           creates: "/var/www/wiki.example.com/code/wiki_example_com"
         become: yes
         become_user: admin-wiki_example_com
       - name: Deploy settings for wiki website
         copy:
           src: "{{ item }}"
           dest: "/var/www/wiki.example.com/code/wiki_example_com/{{ item }}"
           mode: 0640
           owner: admin
           group: web-wiki_example_com
         with_items:
           - settings.py
           - urls.py
         notify:
           - Restart wiki
       - name: Deploy project database and deploy static files
         django_manage:
           command: "{{ item }}"
           app_path: "/var/www/wiki.example.com/code/"
           virtualenv: "/var/www/wiki.example.com/virtualenv/"
         become: yes
         become_user: admin-wiki_example_com
         with_items:
           - migrate
           - collectstatic
       - name: Deploy the superadmin creation script
         copy:
           src: "create_superadmin.py"
           dest: "/var/www/wiki.example.com/code/create_superadmin.py"
           owner: admin-wiki_example_com
           group: web-wiki_example_com
           mode: 0750
       - name: Create initial superuser
         command: "/var/www/wiki.example.com/virtualenv/bin/exec ./create_superadmin.py"
         args:
           chdir: "/var/www/wiki.example.com/code/"
         become: yes
         become_user: admin-wiki_example_com
         register: wiki_superuser
         changed_when: "wiki_superuser.stdout ==  'Created superuser.'"
    :file:`~/mysite/roles/wiki/handlers/main.yml`
    ::
       ---
       - name: Restart wiki
         service:
           name: wiki.example.com
           state: restarted
 . There is a couple of files that we are deploying through the above
    tasks. Let's create them as well.
    :file:`~/mysite/roles/wiki/files/settings.py`
    ::
       """
       Django settings for wiki_example_com project.
       For more information on this file, see
       https://docs.djangoproject.com/en/2.2/topics/settings/
       For the full list of settings and their values, see
       https://docs.djangoproject.com/en/2.2/ref/settings/
       """
       import os
       from django.urls import reverse_lazy
       # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
       BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
       # Quick-start development settings - unsuitable for production
       # See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/
       # SECURITY WARNING: keep the secret key used in production secret!
       SECRET_KEY = '8rok13az%bqtb=ya&s9sia_x*@@rhd9a%g=!6nh4tb!g14rlt^'
       # SECURITY WARNING: don't run with debug turned on in production!
       DEBUG = False
       ALLOWED_HOSTS = ["wiki.example.com", "localhost"]
       # Application definition
       INSTALLED_APPS = [
           'django.contrib.admin',
           'django.contrib.auth',
           'django.contrib.contenttypes',
           'django.contrib.sessions',
           'django.contrib.messages',
           'django.contrib.staticfiles',
           'django.contrib.sites.apps.SitesConfig',
           'django.contrib.humanize.apps.HumanizeConfig',
           'django_nyt.apps.DjangoNytConfig',
           'mptt',
           'sekizai',
           'sorl.thumbnail',
           'wiki.apps.WikiConfig',
           'wiki.plugins.attachments.apps.AttachmentsConfig',
           'wiki.plugins.notifications.apps.NotificationsConfig',
           'wiki.plugins.images.apps.ImagesConfig',
           'wiki.plugins.macros.apps.MacrosConfig',
+      ]
       MIDDLEWARE = [
           'django.middleware.security.SecurityMiddleware',
           'django.contrib.sessions.middleware.SessionMiddleware',
           'django.middleware.common.CommonMiddleware',
           'django.middleware.csrf.CsrfViewMiddleware',
           'django.contrib.auth.middleware.AuthenticationMiddleware',
           'django.contrib.messages.middleware.MessageMiddleware',
           'django.middleware.clickjacking.XFrameOptionsMiddleware',
+      ]
       ROOT_URLCONF = 'wiki_example_com.urls'
       TEMPLATES = [
+          {
               'BACKEND': 'django.template.backends.django.DjangoTemplates',
               'DIRS': [],
               'APP_DIRS': True,
               'OPTIONS': {
                   'context_processors': [
                       'django.contrib.auth.context_processors.auth',
                       'django.template.context_processors.debug',
                       'django.template.context_processors.i18n',
                       'django.template.context_processors.media',
                       'django.template.context_processors.request',
                       'django.template.context_processors.static',
                       'django.template.context_processors.tz',
                       'django.contrib.messages.context_processors.messages',
                       "sekizai.context_processors.sekizai",
                   ],
               },
           },
+      ]
       WSGI_APPLICATION = 'wiki_example_com.wsgi.application'
       # Database
       # https://docs.djangoproject.com/en/2.2/ref/settings/#databases
       DATABASES = {
           'default': {
               'ENGINE': 'django.db.backends.mysql',
               'NAME': 'wiki',
               'USER': 'wiki',
               'PASSWORD': 'wiki',
               'HOST': '127.0.0.1',
               'PORT': '3306',
+          }
+      }
       # Password validation
       # https://docs.djangoproject.com/en/2.2/ref/settings/#auth-password-validators
       AUTH_PASSWORD_VALIDATORS = [
+          {
               'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
           },
+          {
               'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
           },
+          {
               'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
           },
+          {
               'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
           },
+      ]
       # Internationalization
       # https://docs.djangoproject.com/en/2.2/topics/i18n/
       LANGUAGE_CODE = 'en-us'
       TIME_ZONE = 'Europe/Stockholm'
       USE_I18N = True
       USE_L10N = True
       USE_TZ = True
       # Static files (CSS, JavaScript, Images)
       # https://docs.djangoproject.com/en/2.2/howto/static-files/
       STATIC_URL = '/static/'
       STATIC_ROOT = '/var/www/wiki.example.com/htdocs/static'
       SITE_ID = 1
       LOGIN_REDIRECT_URL = reverse_lazy('wiki:get', kwargs={'path': ''})
    :file:`~/mysite/roles/wiki/files/urls.py`
    ::
       from django.contrib import admin
       from django.urls import path, include
       urlpatterns = [
           path('admin/', admin.site.urls),
           path('notifications/', include('django_nyt.urls')),
           path('', include('wiki.urls'))
+      ]
    :file:`~/mysite/roles/wiki/files/create_superadmin.py`
    ::
       #!/usr/bin/env python
       import os
       from django import setup
       os.environ['DJANGO_SETTINGS_MODULE']='wiki_example_com.settings'
       setup()
       from django.conf import settings
       from django.contrib.auth.models import User
       User.objects.all()
       if len(User.objects.filter(username="admin")) == 0:
           User.objects.create_superuser('admin', 'john.doe@example.com', 'admin')
           print("Created superuser.")
 . Time to add the new role to our web server.
    :file:`~/mysite/playbooks/web.yml`
    ::
       ---
       - hosts: web
         remote_user: ansible
         become: yes
         roles:
           - common
           - ldap_client
           - mail_forwarder
           - web_server
           - database_server
           - tbg
           - wiki
 . Apply the changes:
    ::
      workon mysite && ansible-playbook playbooks/site.yml
 . At this point Django Wiki has been installed, and you should be able to open
    the URL https://wiki.example.com/ and log-in into *Django Wiki* with
    username ``admin`` and password ``admin``.
 Backups, backups, backups!
 --------------------------
 As it is well known, everyone has backups of their important data. Right?
 Riiiiight?
 There are three Ansible roles that implement backup functionality -
 ``backup_server``, ``backup_client``, and ``backup``. Backup is based around the
 use of `Duplicity <http://duplicity.nongnu.org/>`_ and its convenience wrapper,
 `Duply <http://duply.net>`_. Due to this selection, it should be noted that the
 backup clients are the ones making connection to the backup server (not the
 other way around).
 Backups are encrypted and signed using GnuPG before being stored on the backup
 server. Private key used for encryption and signing is therefore stored on the
 client side. This key should not be encrypted in order to allow for unattended
 backups.
 Although not necessary, it is highly recommended to have separation between
 different backup clients and the keys used for encryption and
 signing. I.e. stick to a separate encryption/signing key for each backup
 client. It should be noted that it is also possible to specify additional
 *public* keys to encrypt with. This lets you have a backup decryptable with some
 other, "master" key.
 The backups are transferred to the backup server via SFTP - the
 ``backup_server`` role sets-up a dedicated OpenSSH server instance that limits
 the connecting clients to a SFTP chroot.
 All backups are stored within directory ``/srv/backups`` (on the backup
 server). Within this directory, every client server has a dedicated
 sub-directory, and within this sub-directory another sub-directory called
 ``duplicity``, where the actual *Duplicity* backups are stored. So, for example,
 the directory where backups for ``www.example.com`` are stored at would be
 ``/srv/backups/www.example.com/duplicity``.
 When backups are configured, they are set-up to be running every morning at
 :00. Before the backup run it is possible to run a preparation task, and a lot
 of roles do this in order to create database dumps etc.
 Setting-up the backup server
 ----------------------------
 With the overview of backups out of the way, it is time to set-up the backup
 server itself first. This is a farily simple task to perform, so let's get
 straight to it:
 . Update the playbook for backup server to include the backup server role.
    :file:`~/mysite/playbooks/backup.yml`
    ::
       ---
       - hosts: backup
         remote_user: ansible
         become: yes
         roles:
           - common
           - mail_forwarder
           - backup_server
 . There is just one mandatory parameter for the role - OpenSSH server keys to
    be used for backup-dedicated instance:
    :file:`~/mysite/group_vars/backup.yml`
    ::
       ---
       backup_host_ssh_private_keys:
         rsa: "{{ lookup('file', inventory_dir + '/ssh/bak_rsa_key') }}"
         ed25519: "{{ lookup('file', inventory_dir + '/ssh/bak_ed25519_key') }}"
         ecdsa: "{{ lookup('file', inventory_dir + '/ssh/bak_ecdsa_key') }}"
 . Since we have decided to specify the keys above through file lookup, the
    above-listed keys now need to be generated::
      ssh-keygen -f ~/mysite/ssh/bak_rsa_key -N '' -t rsa
      ssh-keygen -f ~/mysite/ssh/bak_ed25519_key -N '' -t ed25519
      ssh-keygen -f ~/mysite/ssh/bak_ecdsa_key -N '' -t ecdsa
 Adding backup clients
 ---------------------
 Well, that was all nice and dandy, but it does look like something is
 missing... Ah, we haven't really configured any backup clients, right?
 Surprisingly enough, specifying backup clients is optional, but that won't get
 you far.
 Luckily for you, all relevant *Majic Ansible Roles* are *backup-aware*. In other
 words, all the roles have been implemented with support for doing back-ups - it
 is just that by default this functionality is disabled (since you might be
 relying on some other schema to back things up - LVM snapshots or what-not).
 All that is needed is to enable the backups for each role, and provide some
 extra variables required by the ``backup_client`` role.
 For this a set of GnuPG private keys are necessary. These need to be provided as
 ASCII-armoured GnuPG-exported files. For simplicity sake, this example documents
 use of GnuPG keyring in conjunction with Ansible's ``pipe`` lookup.
 So, back to the business:
 . Update the backup server configuration - each client needs to be explicitly
    registered:
    :file:`~/mysite/group_vars/backup.yml`
    ::
       backup_clients:
         - server: comms.example.com
           public_key: "{{ lookup('file', inventory_dir + '/ssh/comms.example.com.pub') }}"
           ip: 10.32.64.19
         - server: www.example.com
           public_key: "{{ lookup('file', inventory_dir + '/ssh/www.example.com.pub') }}"
           ip: 10.32.64.20
         # Ah, this is a bit interesting - we can back-up the backup server
         # itself! Don't worry, though, this is mainly so the logs and home
         # directories are preserved, so it won't take too much space ;)
         - server: bak.example.com
           public_key: "{{ lookup('file', inventory_dir + '/ssh/bak.example.com.pub') }}"
           ip: 127.0.0.1
 . And now to configure backup clients for all servers:
    .. warning::
       By default Ansible's file lookup plugin will strip newlines and
       spaces from the end of the file. This is a problem when
       deploying the RSA ssh keys, since if there is no newline after
       the ``-----END OPENSSH PRIVATE KEY-----`` delimeter, ssh client
       will report error about the format of the key file being
       invalid. Therefore the example below explicitly disables
       stripping newline from the end of the file.
    :file:`~/mysite/group_vars/all.yml`
    ::
       enable_backup: yes
       backup_encryption_key: "{{ lookup('pipe', 'gpg --homedir ~/mysite/gnupg/ --armour --export-secret-keys ' + ansible_fqdn ) }}"
       backup_server: bak.example.com
       backup_server_host_ssh_public_keys:
         - "{{ lookup('file', inventory_dir + '/ssh/bak_rsa_key.pub') }}"
         - "{{ lookup('file', inventory_dir + '/ssh/bak_ed25519_key.pub') }}"
         - "{{ lookup('file', inventory_dir + '/ssh/bak_ecdsa_key.pub') }}"
       backup_ssh_key: "{{ lookup('file', inventory_dir + '/ssh/' + ansible_fqdn, rstrip=False) }}"
 . So, looking at the configuration up there, there is a couple of file lookups
    for getting the variable values, as well as one pipe lookup for fetching the
    encryption keys. For start, let's create the SSH private keys used for client
    log-ins to backup server::
      ssh-keygen -f ~/mysite/ssh/comms.example.com -N ''
      ssh-keygen -f ~/mysite/ssh/www.example.com -N ''
      ssh-keygen -f ~/mysite/ssh/bak.example.com -N ''
 . Next off, a GnuPG keyring needs to be populated with private keys that will
    be used for backup encryption and signing. In total, we need three keys, one
    for each server. The keys should not be encrypted, and they should be named
    after the respective server's FQDN. For simplicity sake, here is a nice
    copy-pastable batch version for doing so:
    .. note:: Key generation requires a lot of entropy. If you are running this
              command on a VM, you may want to ``apt-get install haveged`` to
              speed this up. Please do read up on haveged if deploying to a real
              system, though! Don't trust it blindly!
    ::
      chmod 700 ~/mysite/gnupg
      pkill gpg-agent
      gpg --homedir ~/mysite/gnupg --batch --generate-key << EOF
      Key-Type:RSA
      Key-Length:1024
      Name-Real:comms.example.com
      Expire-Date:0
      %no-protection
      %commit
      Key-Type:RSA
      Key-Length:1024
      Name-Real:www.example.com
      Expire-Date:0
      %no-protection
      %commit
      Key-Type:RSA
      Key-Length:1024
      Name-Real:bak.example.com
      Expire-Date:0
      %no-protection
      %commit
      EOF
 . And... Apply::
      workon mysite && ansible-playbook playbooks/site.yml
 . At this point the backup roles have been set-up everywhere, and the backups
    will be running every day at 02:00 in the morning. Of course, you may want to
    test out a backup yourself immediatelly by running the following command on
    servers::
      duply main backup
    .. note:: For more information on available commands and how to work with
              backup tool, please have look at `Official Duply Pages
              <http://duply.net/>`_.
 Adding backup support to custom roles
 -------------------------------------
 As mentioned before, all of the supplied roles coming with *Majic Ansible Roles*
 include backup support. What gets backed-up depends on the role implementation
 (see role reference for details). What about backup support for custom roles?
 This is something that has to be done by hand. However, it is quite simple to do
 so.
 Backup integration will be demonstrated with the previously implemented
 ``tbg`` role.
 *The Bug Genie* stores most of its data in database, but thanks to the
 ``database`` role its backup is already handled for us. As a side-note, just
 before every backup run the database is dumped and stored in location
 ``/srv/backup/tbg.sql``. That file is subsequently backed-up via *Duply* run.
 What is not backed-up for us, though, are the files uploaded to *The Bug
 Genie*. So let's fix that one.
 . Add the ``backup`` role to list of dependencies. Take note that while the
    ``backup_client`` role deals with basic set-up of backup client and its
    configuration, the ``backup`` role is used to define what should be
    backed-up. It is important to define unique filename for the backup patterns
    file. Take into account that you can use pretty much any globbing pattern
    supported by Duplicity.
    .. warning::
       Make sure the addition is properly aligned in the yaml file to previous
       role dependency definitions.
    :file:`~/mysite/roles/tbg/meta/main.yml`
    .. Small workaround for Sphinx not preserving leading spaces in
       case all lines have the same amount of leading spaces.
    .. code-block:: none
       :name: sphinx_workaround
         - role: backup
           when: enable_backup
           backup_patterns_filename: "tbg"
           backup_patterns:
             - "/var/www/tbg.example.com/files"
 . Apply the changes::
      workon mysite && ansible-playbook playbooks/site.yml
 . Now rerun the backup on server ``www.example.com`` (as root). If you haven't
    uploaded any files, you may want to do so before testing to make sure
    something is backed-up.
 . Now rerun the backup on server ``www.example.com`` (as root). If
    you haven't uploaded any files, you may want to do so before
    testing to make sure something is backed-up. This will require
    enabling file uploads in `The Bug Genie settings
    <https://tbg.example.com/configure/files>`_, creating a test
    project, and then adding a new project release (via project's
    release center). While creating a new project release, it is
    possible to upload a release file.
    ::
      duply main backup
 . Verify that the files have been backed-up:
    ::
       duply main list
 .. note:: If you wanted to run a script prior to backup run, you would simply
           deploy a shell script with desired content to
           ``/etc/duply/main/pre.d/``. Just make sure the permissions for it are
           ok (it has to be executable by the root user).
 Dealing with failures
 ---------------------
 While the roles have been designed to be fairly robust, it should be taken into
 account that certain handlers are used to bring the system into consistent
 state. These handlers are mostly the ones dealing with service restarts, but
 there are also a couple of handlers that take care of transforming certain data
 into the required formats, import of files etc.
 This means that failure to successfully execute such handlers could result in
 inconsistent state on the server. Think of service configuration files being
 updated, yet the service itself is not restarted and therefore continues to run
 with the old configuration.
 Handler execution failure can depend on a couple of things, including the loss
 of SSH connectivity to managed machine, or some kind of unusual time-out during
 handler execution.
 To help handle this situation, Majic Ansible Roles all come with a special way
 to invoke the handlers explicitly. Each role will include handlers as tasks,
 provided that a special variable (``run_handlers``) is passed in to playbook run. To
 make the run shorter, the handlers in such a run are also tagged with
 ``handlers``. This doubling of environment variable + tagging stems from current
 limitations of Ansible (it is not possible to specify that certain task should
 be run only if a tag is specified, therefore an additional variable has to be
 used).
 Handlers alone can be invoked specifically with command similar to::
   ansible-playbook -t handlers -e run_handlers=true playbooks/site.yml
 The ``run_handlers`` variable is treated as boolean, and by default it
 is not set.
 Checking for available package upgrades
 ---------------------------------------
 One of the more annoying chores when you maintain your own infrastructure is
 making sure everything is up-to-date. And this has to be done - both in order to
 ensure for problem-free experience for users (yourself included), and for making
 sure there are no security vulnerabilities that could be exploited by a (random)
 adversary.
 *Majic Ansible Roles* try to keep you covered on this front as well. As part of
 regular deployment, the ``common`` role will deploy and configure ``apticron`` -
 a nifty little script that runs on hourly basis and checks if any of your
 system-provided packages are outdated.
 If ``apticron`` detects an outdated package, it will output this information to
 standard output, which will result in the cron daemon sending out an e-mail to
 the local root account. These mails can be further directed towards other mail
 accounts via aliases (easily achieveable if you use either the
 ``mail_forwarder`` or ``mail_server`` roles).
 No packages will be upgraded automatically - ensuring you can make sure upgrades
 work correctly and do not cause major outage without anyone being present to
 fix them.
 Another useful package you may want to look into is ``needrestart`` - which runs
 as a hook during the upgrade process to detect any processes that seem to be
 running with outdated libraries, allowing you to restart them as well. This
 package is *not* installed by the ``common`` role out-of-the-box, but you can
 easily do so by updating the ``common_packages`` setting.
 In addition to system packages, the ``common`` role makes it easy to check if
 any of the pip requirements files are outdated as well. It should be noted,
 though, that this check does *not* verify the Python virtual environments
 themselves.
 This is primarily useful when you use `pip-tools
 <https://github.com/jazzband/pip-tools>`_ for maintaining the
 requirements files. In fact, I would encourage you to utilise
 ``pip-tools`` for both this purpose and for keeping the virtual
 environment in sync and up-to-date.
 Roles that want to take advantage of this would:
 - Create a sub-directory under
   ``/etc/pip_check_requirements_upgrades/`` (for Python 2
   applications) or ``/etc/pip_check_requirements_upgrades-py3/`` (for
   Python 3 applications).
 - Deploy ``.in`` and ``.txt`` files within the sub-directory (see ``pip-tools``
   docs for explanation of how the ``.in`` files work).
 - Ensure the created sub-directory and files have ownership set to
   ``root:pipreqcheck``.
 .. note::
    If you are using the ``wsgi_website`` role as dependency, simply set-up the
    ``wsgi_requirements`` parameter, and then deploy the ``.in`` and ``.txt``
    file into directory ``/etc/pip_check_requirements_upgrades/FQDN`` (this
    directory is automatically created when ``wsgi_requirements`` is specified).
 Where to go next?
 -----------------
 Well, those were some rather lengthy usage instructions, but hopefuly they are
 useful. Things you might want to check-out next:
 * :ref:`rolereference`
 * :ref:`testsite`
 * Finally, if it tickles your interest, have a look at role implementations
   themselves.

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