majic-ansible-roles Changeset

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Branko Majic (branko) - 6 years ago 2020-05-12 18:35:39
branko@majic.rs

MAR-149: Updated usage documentation:

- Add warning that Majic Ansible Roles support only Python 3.
- Updated the Django Wiki deployment to use Python 3.
- Upgraded the Django Wiki deployment for use with Python 3.
- Removed one stale warning regarding compat links for MariDB devel
files (leftover from Jessie).

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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 Stretch 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 Stretch will be installed on top of this server as part of the
   usage instructions.
 * Debian Stretch 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 python-pip python-dev libffi-dev libssl-dev
+     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 -a ~/mysite/ 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 4.0-dev 4.0-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
       <http://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, and GnuPG keyring (we'll get to this later)::
      mkdir ~/mysite/playbooks/
      mkdir ~/mysite/group_vars/
      mkdir ~/mysite/ssh/
      mkdir ~/mysite/gnupg/
 . Before moving ahead, we should also 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 ''
 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
 . And that's about it... 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. Create a new configuration file:
    :file:`~/mysite/group_vars/preseed.yml`
    ::
       ---
       # 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/stretch/amd64/apbs02.html.en>`_ 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/
-  python -m SimpleHTTPServer 8000
+  python -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). This defaults to content of local file ``~/.ssh/id_rsa.pub``, so no
    need to make any changes so far.
 . 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.
 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
@@ @@ -868,193 +882,193 @@ role. @@
    ::
      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`
    ::
       # First, let's 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 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 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
         # 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: "4.2.0"
           tbg_archive_checksum: "ca3a8b9d8090ec5f75580803abf699c5e67bdea0ec043dd782e525a774cf0936"
       - 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/1.7.2/composer.phar"
           dest: "/usr/local/bin/composer"
           sha256sum: "ec3428d049ae8877f7d102c2ee050dbd51a160fc2dde323f3e126a3b3846750e"
           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: 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"
           mode: 02750
         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: python-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 python
       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`
    ::
 . 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/ (if you open http://tbg.example.com/ ,
    you will be redirected to the HTTPS URL) 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
           # In many cases you need to have some development packages available
           # in order to build Python packages installed via pip
           packages:
             - build-essential
             - python-dev
             - python3-dev
             - libjpeg62-turbo
             - libjpeg-dev
             - libzip-dev
             - libtiff-dev
             - libfreetype6-dev
             - liblcms2-dev
             - libwebp-dev
             - libopenjp2-7-dev
             - libmariadb-client-lgpl-dev
             - libmariadb-client-lgpl-dev-compat
             - 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:
             - pillow
             - django==1.8.13
             - wiki
             - MySQL-python
             - 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
         - 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:
           - syncdb
           - 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/1.6/topics/settings/
+      https://docs.djangoproject.com/en/2.2/topics/settings/
       For the full list of settings and their values, see
-      https://docs.djangoproject.com/en/1.6/ref/settings/
+      https://docs.djangoproject.com/en/2.2/ref/settings/
       """
       # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
       import os
       BASE_DIR = os.path.dirname(os.path.dirname(__file__))
       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/1.6/howto/deployment/checklist/
+      # See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/
       # SECURITY WARNING: keep the secret key used in production secret!
-      SECRET_KEY = 'l^q+t$7h$ebls)v34+w9m9v4$n+^(9guxqntu&#cc4m&lfd-6_'
+      SECRET_KEY = '8rok13az%bqtb=ya&s9sia_x*@@rhd9a%g=!6nh4tb!g14rlt^'
       # SECURITY WARNING: don't run with debug turned on in production!
       DEBUG = False
       TEMPLATE_DEBUG = False
       ALLOWED_HOSTS = ["wiki.example.com", "localhost"]
       # Application definition
-      INSTALLED_APPS = (
+      INSTALLED_APPS = [
           'django.contrib.admin',
           'django.contrib.auth',
           'django.contrib.contenttypes',
           'django.contrib.sessions',
           'django.contrib.messages',
           'django.contrib.staticfiles',
           'django.contrib.sites',
           'django.contrib.humanize',
           'django_nyt',
           'django.contrib.sites.apps.SitesConfig',
           'django.contrib.humanize.apps.HumanizeConfig',
           'django_nyt.apps.DjangoNytConfig',
           'mptt',
           'sekizai',
           'sorl.thumbnail',
           'wiki',
           'wiki.plugins.attachments',
           'wiki.plugins.notifications',
           'wiki.plugins.images',
           'wiki.plugins.macros',
+      )
       MIDDLEWARE_CLASSES = (
           '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/1.6/ref/settings/#databases
+      # 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/1.6/topics/i18n/
+      # 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/1.6/howto/static-files/
+      # https://docs.djangoproject.com/en/2.2/howto/static-files/
       STATIC_URL = '/static/'
       STATIC_ROOT = '/var/www/wiki.example.com/htdocs/static'
       from django.conf import settings
       TEMPLATE_CONTEXT_PROCESSORS = settings.TEMPLATE_CONTEXT_PROCESSORS + (
           "django.core.context_processors.debug",
           "django.core.context_processors.request",
           "sekizai.context_processors.sekizai",
+      )
       SITE_ID = 1
       LOGIN_REDIRECT_URL = reverse_lazy('wiki:get', kwargs={'path': ''})
    :file:`~/mysite/roles/wiki/files/urls.py`
    ::
       from django.conf.urls import patterns, include, url
       from wiki.urls import get_pattern as get_wiki_pattern
       from django_nyt.urls import get_pattern as get_nyt_pattern
       from django.contrib import admin
-      admin.autodiscover()
+      from django.urls import path, include
       urlpatterns = patterns('',
           # Examples:
           # url(r'^$', 'wiki_example_com.views.home', name='home'),
           # url(r'^blog/', include('blog.urls')),
       urlpatterns = [
           path('admin/', admin.site.urls),
           path('notifications/', include('django_nyt.urls')),
           path('', include('wiki.urls'))
+      ]
           url(r'^admin/', include(admin.site.urls)),
+      )
       urlpatterns += patterns('',
           (r'^notifications/', get_nyt_pattern()),
           (r'', get_wiki_pattern())
+      )
    :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:
    .. warning::
       Due to `Debian Bug 766996
       <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766996>`_ Majic Ansible
       Roles try to detect if you install ``libmariadb-client-lgpl-dev-compat``
       package, and create symbolic link from ``/usr/local/bin/mysql_config`` to
       ``/usr/bin/mariadb_config`` automatically. Otherwise the MySQL-python
       package will fail to build due to missing ``mysql_config`` binary.
    ::
      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/ (if you open http://wiki.example.com/ , you
    will be redirected to the HTTPS URL) 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:
         dsa: "{{ lookup('file', inventory_dir + '/ssh/bak_dsa_key') }}"
         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_dsa_key -N '' -t dsa
      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
@@ @@ -2144,193 +2172,198 @@ So, back to the business: @@
 . 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.
    ::
      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.

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