.. _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 `_
- `libffi `_ runtime and development package.
- `OpenSSL `_ runtime and development package.
- `pip `_
- `virtualenv `_
- `virtualenvwrapper `_
- 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
`_ and `Vagrant `_,
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
`_::
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 `_,
`Testinfra `_, `VirtualBox
`_ and `Vagrant
`_. *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).
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_dsa_key -N '' -t dsa
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
8 Jessie* or *Debian 9 Stretch* in any combination desired.
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 `_ (for XMPP)
- `mutt `_ (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