Slides presented at the London Ansible Meetup in December 2018.

1. Managing multiple environments
with Ansible
Jiri Tyr

2. About me
● Using Ansible since 2014
● Ansible contributor
○ Modules: yum_repository , jenkins_plugin , ldap_attr, ldap_entry
○ Jinja2 filter: comment
○ Bug fixing (mount module)
○ Code reviews
● Author of more than 100 publicly available Ansible roles
○ https://github.com/jtyr
○ https://galaxy.ansible.com/jtyr

3. The principle of managing multiple envs

4. The principle of managing multiple envs
● Multiple environments (DEV, QA, STG, PRD)
● The same roles, playbooks, modules, ... in different version in different envs
● Each component has different development velocity
● Shift the components from lower to higher environments in controlled manner
DEV QA STG PRD
Role 1 t22 t10 t5 t3
Role 2 t19 t16 t11 t7
Playbook t10 t7 t4 t2

5. How to achieve it?

6. How to achieve it?
● Single monolithic Git repo?
○ No way!
● Git submodules?
○ Too tricky...
● Separate Git repos?
○ Hm...
○ What tool to use?
■ ansible-galaxy?
■ But that's only for roles! What about playbooks, inventories, modules, plugins, ...?

7. The solution is...

8. Android repo script
● Tool used for managing Android repositories
● Wrapper around Git
● Fetches whatever Git repos into a single work directory
● Individual repos stay as Git repos with all their history
● Integrates with Gerrit code review system
● Using Manifest file (XML)
○ Android Repo Manifest Management tool (armm)

9. Manifest file
<manifest>
<remote name="jtyr-github" fetch="https://github.com/jtyr" />
<default remote="jtyr-github" revision="master" sync-j="4" />
<project name="ansible-test_playbook" path="." />
<project name="ansible-test_role1" path="roles/role1" revision="refs/tags/t1" />
<project name="ansible-test_role2" path="roles/role2" revision="b2d50df" />
<project name="ansible-yaml_inventory" path="tools/yaml_inventory" groups="base">
<linkfile src="yaml_inventory.py" dest="hosts" />
</project>
</manifest>

10. How to use it?

11. How to use it?
# Get the repo script and make it executable
sudo curl -s 'https://gerrit.googlesource.com/git-repo/+/stable/repo?format=TEXT' |
base64 -d > /usr/local/bin/repo
chmod +x /usr/local/bin/repo
# Create the work directory and fetch all components
export ENV=dev
mkdir -p /tmp/ansible/env/$ENV
cd /tmp/ansible/env/$ENV
repo init -u https://github.com/jtyr/ansible-repo-test_manifest.git -b $ENV
repo sync --no-clone-bundle

12. Repo script commands
# Show all possible repo commands
repo help --all
# List all projects
repo list
# Show which files have been modified
repo status
# Show changes across all projects
repo diff
# Sync only particular project
repo sync my_project
# Run command across all projects
repo forall -p -c 'git add -A; git commit -m "My change"; git push'

13. Demo time...

14. Summary
● Keep Ansible components in separate Git repos
● Create an extra Git repo with a Manifest file for each environment
● Use the repo script to build the work directory

15. Thank you for your attention!
Questions?