.. _development:

Development
===========

This section covers procedures and information related to development of *Majic
Ansible Roles*.


Preparing environment
---------------------

The easiest way to get going with role development is to set-up a separate
Python virtual environment with the necessary packages. This can be done by
performing the following steps:

1. Ensure that the following minimum set of packages are installed via
   distribution package manager:

   - `Git <https://git-scm.com/>`_
   - `libffi <https://sourceware.org/libffi/>`_ runtime and development package.
   - `OpenSSL <https://www.openssl.org/>`_ runtime and development package.
   - `pip <https://pypi.python.org/pypi/pip/>`_
   - `virtualenv <https://pypi.python.org/pypi/virtualenv>`_
   - `virtualenvwrapper <https://virtualenvwrapper.readthedocs.io/en/latest/>`_
   - Development packages for Python.

   On Debian this can be easily done with::

     apt-get install virtualenv virtualenvwrapper git python-pip python-dev \
     libffi-dev libssl-dev

2. In order to be able to run role tests, it is necessary to install `VirtualBox
   <https://www.virtualbox.org/>`_ and `Vagrant <https://www.vagrantup.com/>`_,
   using instructions outlined on their respective websites. It is recommended
   to use latest versions available. At time of this writing the role tests have
   been successfully run on *VirtualBox 5.2.12* and *Vagrant 2.0.4*.

3. Clone the git repository::

     git clone https://code.majic.rs/majic-ansible-roles/ ~/projects/

4. Create a separate Python virtual environment::

     mkvirtualenv majic-ansible-roles -a ~/projects/majic-ansible-roles/

5. Make sure the virtual environment has been activated, and install `pip-tools
   <https://github.com/jazzband/pip-tools>`_::

     workon majic-ansible-roles
     pip install pip-tools

6. Synchronise Python virtual environment with requirements file using
   **pip-tools**::

     workon majic-ansible-roles
     pip-sync


Development conventions
-----------------------

In order to maintain consistency across different roles and documentation, this
section describes development conventions that should be followed while making
modifications.


Task specifications
~~~~~~~~~~~~~~~~~~~

When writing new and updating existing tasks, keep the following in mind:

- Quote sensibly. If specifying paths (for example ``src``, ``dest``, ``path``
  etc in various models), quote the string to make it stand-out better and to
  avoid breakages.
- Avoid usage of ``set_facts`` task when same functionality can be achieved via
  ``defaults/main.yml``.
- When specifying tasks, use the fully expanded form. Do not use single-line
  form with ``param=value``.
- When specifying ``command`` or ``shell`` tasks, in case a ``creates``
  parameter or such need to be used, specify them as part of task's ``args``
  parameter. E.g.::

    - name: Run command
      command: mycommand
      args:
        creates: "/etc/mycommand"

- When sepcifying tasks, keep the following ordering between different task
  parameters:

  - ``name``
  - Module and its parameters.
  - ``become``
  - ``become_user``
  - ``when``
  - ``with_items`` / ``with_dict`` / ``with_nested``
  - ``wait_for``
  - ``register``
  - ``changed_when``
  - ``failed_when``
  - ``no_log``
  - ``notify``
  - Task tags.


Running role tests directly
---------------------------

Role tests are implemented using `Molecule <https://molecule.readthedocs.io/>`_,
`Testinfra <https://testinfra.readthedocs.io/en/latest/>`_, `VirtualBox
<https://www.virtualbox.org/>`_ and `Vagrant
<https://www.vagrantup.com/>`_. *Molecule* and *Testinfra* are installed inside
of Pyhton virtual environment, while *VirtualBox* and *Vagrant* need to be
installed distribution-wide, following instructions outlined on their
corresponding websites.

Tests can be run directly for a single role, or for one or more roles using a
dedicated shell script (see below). The shell script can also be used for
generating reports in an automated environment.

In order to run tests for a specific role, perform the following steps:

1. Switch to Python virtual environment::

     workon majic-ansible-roles

2. Change directory::

     cd roles/ROLENAME/

3. Run the default test scenario (this will normally test against
   multiple Debian versions if supported)::

     molecule test


Running role tests via shell script
-----------------------------------

In order to make it easier to run tests for all roles, and eventually produce
reports of such runs, a dedicated shell script is provided for running the
tests.

In order to run tests, perform the following steps:

1. Switch to Python virtual environment::

     workon majic-ansible-roles

2. Make sure you are within the root directory of Git repository.

3. Run tests for all roles and generate report::

     ./scripts/run_tests.sh -r all

   .. note::
      Optionally you can run tests for a specific set of roles, or without
      generating the report, for example ``./scripts/run_tests.sh web_server
      common``

4. Check results either from script output, or within directory
   ``test_report-YYYY_MM_DD-hh_mm_ss``. For overview of what roles have failed,
   have a look at ``summary.txt``. For details have a look at each role's
   individual report.


Porting to Molecule 2.4.x and Testinfra 1.7.1
---------------------------------------------

The following instructions were applicable during the porting to new
Molecule and Testinfra version. The transition made was:

- Molecule 1.25.0 to Molecule 2.4.0.
- Testinfra 1.5.5 to Testinfra 1.7.1.

Instructions hold only some historical value.

For each role perform the following steps:

1. Go to role directory::

     workon majic-ansible-roles
     cd roles/ROLE_NAME

2. Create default scenario::

     molecule init scenario -s default -d vagrant -r ROLE_NAME

3. Remove unneded files::

     rm molecule/default/INSTALL.rst

4. Move all tests into new location::

     rm -rf molecule/default/tests/
     git mv tests molecule/default/

5. Port the old ``molecule.yml`` configuration into
   ``molecule/default/molecule.yml``.

   1. A good starting template for new Molecule configuration file
      would be::

        ---

        dependency: {}

        driver:
          name: vagrant
          provider:
            name: virtualbox

        lint:
          name: yamllint

        platforms:
          - name: helper
            box: debian/contrib-jessie64
            memory: 512
            cpus: 1
            interfaces:
              - auto_config: true
                ip: 10.31.127.2
                network_name: private_network
                type: static

          - name: parameters-mandatory-jessie64
            groups:
              - parameters-mandatory
            box: debian/contrib-jessie64
            memory: 256
            cpus: 1
            interfaces:
              - auto_config: true
                ip: 10.31.127.3
                network_name: private_network
                type: static

          - name: parameters-optional-jessie64
            groups:
              - parameters-optional
            box: debian/contrib-jessie64
            memory: 256
            cpus: 1
            interfaces:
              - auto_config: true
                ip: 10.31.127.4
                network_name: private_network
                type: static

          - name: parameters-mandatory-stretch64
            groups:
              - parameters-mandatory
            box: debian/contrib-stretch64
            memory: 256
            cpus: 1
            interfaces:
              - auto_config: true
                ip: 10.31.127.5
                network_name: private_network
                type: static

          - name: parameters-optional-stretch64
            groups:
              - parameters-optional
            box: debian/contrib-stretch64
            memory: 256
            cpus: 1
            interfaces:
              - auto_config: true
                ip: 10.31.127.6
                network_name: private_network
                type: static

        provisioner:
          name: ansible
          config_options:
            ssh_connection:
              pipelining: "True"
          lint:
            name: ansible-lint

        scenario:
          name: default

        verifier:
          name: testinfra
          lint:
            name: flake8

   2. Ensure to define additional hosts for different platforms (as
      supported by the role). If only a single platform is supported,
      still perform the rename.

   3. Make sure the IP addresses are not coliding.

   4. Make sure to add hosts to correct groups that will correspond to
      groups within ``playbook.yml``.

   5. Remove old Molecule configuration::

        git rm molecule.yml

6. Move the old playbook into new location::

     rm molecule/default/playbook.yml
     git mv playbook.yml molecule/default/playbook.yml

7. Update the playbook:

   1. Move idempotent parts of ``molecule/default/playbook.yml`` into
      ``molecule/default/prepare.yml``. Only the role-related set-up
      should remain.

      .. warning::
         Don't forget to add the ``become: yes`` to tasks.

   2. Update IP address information where necessary. Especially
      important in case of multiple Debian versions.

8. Update tests to use correct fixtures and Ansible inventory::

     sed -i -e 's/Ansible(/host.ansible(/g;s/File(/host.file(/g;s/Group(/host.group(/g;s/LocalCommand(/local.run(/g;s/Package(/host.package(/g;s/PipPackage(/host.pip_package(/g;s/Service(/host.service(/g;s/Socket(/host.socket(/g;s/Sudo(/host.sudo(/g;s/User(/host.user(/g;s/Command(/host.run(/g' molecule/default/tests/test_*.py
     sed -i -r -e 's/^(def test.*)\(.*\):/\1(host):/' molecule/default/tests/test_*.py
     sed -i -e "s#'.molecule/ansible_inventory'#'.molecule/ansible_inventory.yml'#" molecule/default/tests/test_*.py

9. Start fixing the tests:

   1. Locate all instances of ``local.run``, and ensure the ``local``
      variable is initialised once prior to use in each test.

      Commands can be found with::

        grep 'local.run' molecule/default/tests/test_*.py

      Snippet to insert::

        local = host.get_host("local://")

   2. Run linting checks, fixing any ensuing issues along the way::

        molecule lint

   3. Bring-up the machines, fixing any ensuing issues along the way::

        molecule converge

   4. Run idempotency test, fixing any ensuing issues along the way::

        molecule idempotence

   5. Figure out how to fix IP parametrisation of IPs in case of
      multiple (old) platforms, e.g. when having same machines with
      multiple debian versions. Good way to identify such tests::

        grep -ri 10.31 molecule/default/tests/test_*.py

   6. Figure out how to fix hostname parametrisation in case of
      multiple (old) platforms, e.g. when having same machines with
      multiple debian versions. Good way to identify such tests::

        grep -ri parameters- molecule/default/tests/test_*.py

   7. Run tests, fixing any ensuing issues along the way::

        molecule verify

   8. Perform one more relatively fast verification that things work
      fine::

        molecule lint && molecule idempotence && molecule verify

   9. Check the number of defined tests against number of tests
      performed. Keep in mind some tests are run for multiple
      machines, and refer to each test file to see what hosts will get
      loaded::
      
        grep -c 'def test_' molecule/default/tests/test_*

   10. Run the full test suite to ensure everything works correctly::

         molecule test

10. Verify and commit the changes. Template commit message::

      MAR-128: Upgraded tests for ROLE_NAME role:

      - Switch to new Molecule configuration.
      - Updated set-up playbook to use become: yes.
      - Moved some preparatory steps outside of the main playbook (eases
        idempotence tests).
      - Updated tests to reference the yml inventory file.
      - Updated tests to use new fixture (host instead of individual ones).
      - Switched to extracting IP address instead of hard-coding it in a
        couple of tests.



.. _testsite:

Test Site
---------

*Majic Ansible Roles* comes with a small sample test site configuration which
demonstrates use of every role. This test site also serves as starting point for
developing new roles etc, and can be used for testing regressions/breakages.

The test site covers everything, starting from generating the Debian preseed
files, through bootstrap process for new nodes, and onto deployment of all
remaining roles.

By default, the test site uses domain ``example.com``, but it has been designed
so it is easy to set your own domain (see below in step-by-step
instructions). Some changes may be necessary to listed commands in that case
(i.e. replace every occurance of ``example.com`` with your own domain).

By default, the following hosts are used in test site (listed names
should be resolvable towards the servers):

- ``ldap.example.com``, acting as LDAP server
- ``xmpp.example.com``, acting as XMPP server
- ``mail.example.com``, acting as mail server
- ``web.example.com``, acting as web server
- ``backup.example.com``, acting as backup server
- ``ws01.example.com``, acting as "workstation" (mainly demonstrating
  use of mail forwarder role)

The web server is also set-up with one sample PHP application and two
WSGI applications deployed via roles:

- ``phpinfo``, used to serve information about the local PHP
  installation.
- ``wsgihello``, small hello world application using Python 2
- ``wsgihello2``, small hello world application using Python 3 and a
  couple of additional ``wsgi_website`` role parameters.

To make the web applications reachable, make sure the web server
(``web.example.com``) IP is also resolvable via names:

- ``phpinfo.example.com`` (``phpinfo`` application/role)
- ``wsgi.example.com`` (``wsgihello`` application/role)
- ``wsgireq.example.com`` (``wsgihello2`` application/role)

All example commands listed within this section should be ran from within the
``testsite`` directory in order to have proper environment available for
playbook runs.

A number of playbooks is provided out of the box:

bootstrap.yml (for bootstrapping fresh nodes)
  This playbook can be used for bootstrapping fresh nodes. By default, the
  entire test site will be included in the bootstrap. If you wish to limit
  bootstrap to a single server, just run the playbook with (for example):

  .. code-block:: shell

    ansible-playbook -l ldap.example.com playbooks/bootstrap.yml

ldap.yml
  This playbook sets-up the LDAP servers. It is included in ``site.yml``.

mail.yml
  This playbook sets-up the mail server. It is included in ``site.yml``.

preseed.yml
  This playbook sets-up the Debian preseed files. It is included in
  ``site.yml``.

site.yml
  This playbook sets-up all servers, including preseed files on local host.

web.yml
  This playbook sets-up the web server. It is included in ``site.yml``.

xmpp.yml
  This playbook sets-up the XMPP server. It is included in ``site.yml``.

backup.yml
  This playbook sets-up the backup server. It is included in ``site.yml``.

The playbooks and configurations for test site make a couple of assumptions:

* Each server will be set-up with an operating system user ``admin``, capable of
  running the sudo commands.
* The password for operating system user ``admin`` is hard-coded to ``admin``.
* An SSH ``authorized_keys`` file is set-up for the operating system user
  ``admin``. The SSH key stored in it will be read from location
  ``~/.ssh/id_rsa.pub`` (i.e. from home directory of user running the Ansible
  commands).

For more details on how the playbooks and configuration have been implemented,
feel free to browse the test site files (in directory ``testsite``).


Deploying test site
~~~~~~~~~~~~~~~~~~~

In order to deploy the test site, the following steps would normally be taken:

1. As mentioned in introduction, default domain used by test site is
   ``example.com``. To change it, perform the following steps (otherwise, just
   skip to step 2):

   a. Update the file ``hosts``. Simply replace all occurances of
      ``example.com`` with your chosen domain.
   b. Update the file ``group_vars/all.yml``, changing the value of variable
      ``testsite_domain``. This value will then be used to calculate some of
      derived values, like LDAP base DN (which will be set to something along
      the lines of ``dc=example,dc=com`` or
      ``dc=your,dc=domain,dc=components``).

2. If you do not wish to have the hassle of creating the private keys and
   issuing certificates, there is a small playbook that can help you with
   this. Just run the ``tls.yml`` playbook, and skip to step 6 (otherwise follow
   steps 3 through 5):

   .. code-block:: shell

     ansible-playbook playbooks/tls.yml

3. Create TLS private keys (relative to top level directory), making sure to
   change domain in filenames if necessary:

   - ``testsite/tls/mail.example.com_imap.key``
   - ``testsite/tls/mail.example.com_smtp.key``
   - ``testsite/tls/xmpp.example.com_xmpp.key``
   - ``testsite/tls/ldap.example.com_ldap.key``
   - ``testsite/tls/web.example.com_https.key``
   - ``testsite/tls/phpfino.example.com_https.key``
   - ``testsite/tls/wsgi.example.com_https.key``
   - ``testsite/tls/wsgireq.example.com_https.key``

4. Issue TLS certificates corresponding to the generated TLS private keys
   (correct FQDN for DNS subject alternative name **must** be used), making sure
   to change domain in filenames if necessary:

   - ``testsite/tls/mail.example.com_imap.pem`` (subject alternative name should
     be ``mail.example.com``)
   - ``testsite/tls/mail.example.com_smtp.pem`` (subject alternative name should
     be ``mail.example.com``)
   - ``testsite/tls/xmpp.example.com_xmpp.pem`` (subject alternative name should
     be ``xmpp.example.com``)
   - ``testsite/tls/ldap.example.com_ldap.pem`` (subject alternative name should
     be ``ldap.example.com``)
   - ``testsite/tls/web.example.com_https.pem`` (subject alternative name should
     be ``web.example.com``)
   - ``testsite/tls/web.example.com_https.pem`` (subject alternative name should
     be ``web.example.com``)
   - ``testsite/tls/phpinfo.example.com_https.pem`` (subject alternative name
     should be ``phpinfo.example.com``)
   - ``testsite/tls/wsgi.example.com_https.pem`` (subject alternative name
     should be ``wsgi.example.com``)
   - ``testsite/tls/wsgireq.example.com_https.pem`` (subject alternative name
     should be ``wsgireq.example.com``)

5. Create ``PEM`` truststore file which contains all CA certificates that form
   CA chain for the issued end entity certificates from previous step at
   location ``testsite/tls/ca.pem``. It is very important to
   include the full CA chain used for LDAP server.

6. Generate SSH keys to be used by the backup server and backup clients:

  .. code-block:: shell

     mkdir ssh
     ssh-keygen -f ssh/backup_server_rsa_key -N '' -t rsa
     ssh-keygen -f ssh/backup_server_ed25519_key -N '' -t ed25519
     ssh-keygen -f ssh/backup_server_ecdsa_key -N '' -t ecdsa
     ssh-keygen -f ssh/mail.example.com -N ''
     ssh-keygen -f ssh/ldap.example.com -N ''
     ssh-keygen -f ssh/xmpp.example.com -N ''
     ssh-keygen -f ssh/web.example.com -N ''
     ssh-keygen -f ssh/backup.example.com -N ''
     ssh-keygen -f ssh/ws01.example.com -N ''

7. Set-up a local GnuPG keyring that will contain the necessary encryption and
   signing keys for the backup clients::

     mkdir ./backup_keyring
     chmod 700 ./backup_keyring
     cat << EOF | gpg2 --homedir ./backup_keyring --batch --gen-key
     Key-Type:RSA
     Key-Length:1024
     Name-Real:ldap.example.com
     Expire-Date:0
     %no-protection
     %commit

     Key-Type:RSA
     Key-Length:1024
     Name-Real:mail.example.com
     Expire-Date:0
     %no-protection
     %commit

     Key-Type:RSA
     Key-Length:1024
     Name-Real:web.example.com
     Expire-Date:0
     %no-protection
     %commit

     Key-Type:RSA
     Key-Length:1024
     Name-Real:xmpp.example.com
     Expire-Date:0
     %no-protection
     %commit

     Key-Type:RSA
     Key-Length:1024
     Name-Real:backup.example.com
     Expire-Date:0
     %no-protection
     %commit

     Key-Type:RSA
     Key-Length:1024
     Name-Real:ws01.example.com
     Expire-Date:0
     %no-protection
     %commit
     EOF

8. Generate the preseed files:

  .. code-block:: shell

     ansible-playbook playbooks/preseed.yml

9. Install all servers using the generated preseed files. Use *Debian
   9 Stretch*.

10. Add the SSH host fingerprints to your ``known_hosts`` file (don't forget to
    remove old entries if you are redoing the process). You can easily obtain all
    the necessary fingerprints with command (don't forget to modify domain if you
    need to):

    .. code-block:: shell

      ssh-keyscan -t ed25519 mail.example.com ldap.example.com xmpp.example.com web.example.com backup.example.com ws01.example.com $(dig +short mail.example.com) $(dig +short ldap.example.com) $(dig +short xmpp.example.com) $(dig +short web.example.com) $(dig +short backup.example.com) $(dig +short ws01.example.com)

11. Invoke the ``bootstrap.yml`` playbook in order to set-up some basic
    environment for Ansible runs on all servers:

    .. code-block:: shell

       ansible-playbook playbooks/bootstrap.yml

12. Finally, apply configuration on all servers:

    .. code-block:: shell

       ansible-playbook playbooks/site.yml


Trying the test site out
~~~~~~~~~~~~~~~~~~~~~~~~

The test site ships with configuration files for a number of CLI-based
tools/applications that can be easily used for trying the services out
(you can otherwise set-up your own).

Configuration files assume the default domain (``example.com``) is
used.

The following tools come with out-of-the-box configuration:

- `mcabber <https://mcabber.com/>`_ (for XMPP)
- `mutt <http://www.mutt.org/>`_ (for IMAP/SMTP)

In order to use the configuration files, make sure that you are
running all tools from within the ``testsite/`` directory.

To start the XMPP CLI client (*mcabber*) with provided configuration,
run (take note it is lower-caser ``f``)::

  mcabber -f mcabber/john.doe
  mcabber -f mcabber/jane.doe

To start the IMAP/SMTP CLI client (*Mutt*) with provided
configuration, run (take note it is upper-case ``F``)::

  mutt -F mutt/john.doe
  mutt -F mutt/jane.doe

To test the provided web applications, use the following links in a
browser:

.. note::
   To avoid untrusted certificate errors, it is recommended to test
   the links with dedicated instance of Mozilla Firefox, and to import
   the CA certificate (``tls/ca.pem``) into it.

- https://phpinfo.example.com/
- https://wsgi.example.com/
- https://wsgireq.example.com/