How to automatically install Ansible Galaxy roles?

Question

All my Ansible playbooks/roles are checked in to my git repo.

However, for Ansible Galaxy roles I always have to explicitly download them one by one on every machine I want to run Ansible from.

It's even tough to know in advance exactly which Ansible Galaxy roles are needed until Ansible complains about a missing role at runtime.

How is one supposed to manage the Ansible Galaxy role dependencies? I would like to either have them checked into my git repo along with the rest of my ansible code or have them automatically be identified and downloaded when I run Ansible on a new machine.

Answer 1

You should use a requirements.yml file for this use-case. Describe the roles you require, using any of a variety of install methods:

# Install a role from the Ansible Galaxy
- src: dfarrell07.opendaylight

# Install a role from GitHub
- name: opendaylight
  src: https://github.com/dfarrell07/ansible-opendaylight

# Install a role from a specific git branch
- name: opendaylight
  src: https://github.com/dfarrell07/ansible-opendaylight
  version: origin/master

# Install a role at a specific tag from GitHub
- name: opendaylight
  src: https://github.com/dfarrell07/ansible-opendaylight
  version: 1.0.0

# Install a role at a specific commit from GitHub
- name: opendaylight
  src: https://github.com/dfarrell07/ansible-opendaylight
  version: <commit hash>

Then install them:

ansible-galaxy install -r requirements.yml

Here's a working example (installing OpenDaylight using Ansible as a Vagrant provisioner). See the relevant Ansible docs for more info.

Answer 2

As suggested, you can use ansible galaxy for this need.

Ansible has a feature where you can create a requirements.yml file that lists all of your roles. You can find out about that here: http://docs.ansible.com/ansible/latest/galaxy.html#installing-multiple-roles-from-a-file

For example (requirements.yml):

- src: yatesr.timezone

You then run ansible-galaxy install -r requirements.yml on this file to download all of the roles listed there.

If you would like to further automate it then, you can create a simple shell script that will run the two commands.

For example (ansible.sh):

./ansible.sh

ansible-galaxy install -r requirements.yml
ansible-playbook playbook.yml -i inventory 

Answer 3

I often find myself installing installing a Java JDK. Using a role makes that touch easier. I've tried a couple of different ways (including lots of .gitmodules and submodule... I have to use multiple git systems for work and all it gets ugly). My largest requirement is that I not check role code into my playbook project, mostly so I can keep everything in one place.

The contents of my 'requirements.yml' file:

- src: https://github.com/staylorx/ansible-role-wls-prep.git
  version: master
  name: staylorx.wls-prep

- src: https://my-work-git-extravaganza.com
  version: 2.x
  name: coolplace.niftyrole

#From Ansible Galaxy
- src: staylorx.oracle-jdk

I run a separate playbook, install-roles.yml:

---

- hosts: localhost

  tasks:
    - file:
        path:  roles
        state: absent

    - local_action:
        command ansible-galaxy install -r requirements.yml --roles-path roles

    - lineinfile:
        dest:   .gitignore
        regexp: '^\/roles$'
        line:   '/roles'
        state:  present

I run this first playbook, then I run my roles in any playbook normally. For me the secret is to ensure it's ignored by git so I don't check the roles in by mistake. Also since I wipe out the folder every time, I ensure I don't need to force or ignore errors.

Answer 4

Another solution is to use git submodules. After all, Ansible Galaxy only is a directory of github repositories...

I use this command to automatically add any Galaxy role as a submodule:

ansible-galaxy info <package> | grep -A 1 github_repo | tr '\n' ' ' | sed -e "s/.*github_repo: \([^[:space:]]*\)[^\w]*github_user: \([^[:space:]]*\)[[:space:]]*/git submodule add git:\/\/github.com\/\2\/\1.git roles\/\2.\1/g" | sh

Commit the changes then to your git repo. When you clone your repo in future make sure to clone it with submodules, e.g. git clone ... --recursive

An advantage of this is, a git submodule is always referencing a specific version (git commit-hash). This will prevent you from running untested updates in your productive environment. A new version of a Galaxy role could have bugs or work completely different than before. With a git submodule you decide if and when you update a role to the new version.

Also, you won't have to additionally take care of blacklisting galaxy roles in your .gitignore to prevent committing their code to your repository.

Answer 5

At this point in time, as far as I know there's no automatic way to download roles at runtime. Your best bet is to either commit them into your own repo or have a proper documentation listing all the requirements. You could even create a pre-flight playbook that installs your roles. :)

Answer 6

You could use an Ansible role to install other the needed roles using the command module.

Here is a very basic example that runs ansible-galaxy install:

- name: Install roles from Ansible Galaxy
  command: ansible-galaxy install {{ item.item }}
  with_items:
    - "{{ ansible_roles_list }}"

The ansible_roles_list may be supplied as a variable or as a role parameter.

I implemented a role for this, so you can use Ansible also to setup (part of) the control machine: https://galaxy.ansible.com/ferrarimarco/install-roles/.

This role has to be applied before any other roles that you want to install using it, in a separate playbook. This is because Ansible checks the if all the roles are available before running the playbook where you reference them.