8. Ansible Collections

In this lab we are going to learn how to use Ansible collections.

Task 1

Create a collection with the ansible-galaxy collection command. Choose a namespace and a collection name of your liking.
Have a look at what folders have been created.

Solution Task 1

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$ pwd
/home/ansible/techlab
$ ansible-galaxy collection init puzzle.ansible_techlab
- Collection puzzle.ansible_techlab was created successfully
$ tree
.
├── ansible.cfg
├── collections.yml
├── hosts
├── puzzle
│   └── ansible_techlab
│       ├── docs
│       ├── galaxy.yml
│       ├── plugins
│       │   └── README.md
│       ├── README.md
│       └── roles
└── requirements.yml

5 directories, 7 files
[ansible@master-controller techlab]$

Task 2

Build a collection from your newly initialized collection-skeleton. Have a close look at the name that was set.
Change the namespace and collection name in the file galaxy.yml in the skeleton.
Rebuild the collection and see the new name.

Tip

Check the dev guide for details about the structure of a collection and the content of the galaxy.yml file.

The information about the place of the playbook is not complete yet. Just try… 😉

Solution Task 2

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$ ansible-galaxy collection build puzzle/ansible_techlab/
Created collection for puzzle.ansible_techlab at /home/ansible/techlab/puzzle-ansible_techlab-1.0.0.tar.gz

$ vim /home/ansible/techlab/puzzle/ansible_techlab/galaxy.yml

$ grep ^name /home/ansible/techlab/puzzle/ansible_techlab/galaxy.yml 
namespace: newpuzzle
name: ansible_techlab2

$ ansible-galaxy collection build puzzle/ansible_techlab/
Created collection for newpuzzle.ansible_techlab2 at /home/ansible/techlab/newpuzzle-ansible_techlab2-1.0.0.tar.gz

Task 3

Install one of your newly built collections from the tar.gz file. See where it was installed.
Have a look at the ansible configuration and figure out why it was installed there.

Tip

With ansible-config dump you can even see the default configuration values not explicitly set in the ansible.cfg file. Look for COLLECTIONS_PATHS.

Change the ansible configuration so that the collection gets installed at /home/ansible/techlab/collections.
Reinstall the tar.gz file of the collection and verify the new location.

Tip

Note the subfolder ansible-collections that was created. This is default ansible behavior.

Solution Task 3

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$ ansible-galaxy collection install puzzle-ansible_techlab-1.0.0.tar.gz 
Process install dependency map
Starting collection install process
Installing 'puzzle.ansible_techlab:1.0.0' to '/home/ansible/.ansible/collections/ansible_collections/puzzle/ansible_techlab'

$ ansible-config dump | grep COLLECTIONS_PATHS
COLLECTIONS_PATHS(default) = [u'/home/ansible/.ansible/collections', u'/usr/share/ansible/collections']

$ vim ansible.cfg
$ grep "\[defaults\]" -A1 ansible.cfg 
[defaults]
collections_paths = /home/ansible/techlab/collections

$ ansible-galaxy collection install puzzle-ansible_techlab-1.0.0.tar.gz 
Process install dependency map
Starting collection install process
Installing 'puzzle.ansible_techlab:1.0.0' to '/home/ansible/techlab/collections/ansible_collections/puzzle/ansible_techlab'

Task 4

Use ansible-config dump to see what default galaxy server is configured
Add another galaxy server to your GALAXY_SERVER_LIST. This entry can point to a nonexistent galaxy server.
Set it explicitly to galaxy.ansible.com in the ansible.cfg file, even though this is the default value.
Review the setting with ansible-config dump.

Solution Task 4

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$ ansible-config dump | grep -i galaxy_server
GALAXY_SERVER(default) = https://galaxy.ansible.com
GALAXY_SERVER_LIST(default) = None

Add the following block to your /home/ansible/techlab/ansible.cfg:

[galaxy]
server_list = puzzle_galaxy

[galaxy_server.puzzle_galaxy]
url = https://galaxy.ansible.com

$ ansible-config dump | grep GALAXY_SERVER
GALAXY_SERVER(default) = https://galaxy.ansible.com
GALAXY_SERVER_LIST(/home/ansible/techlab/ansible.cfg) = ['puzzle_galaxy']
[ansible@master-controller techlab]$

Task 5

Install the collection nginx_controller, provided by the company NGINX (nginxinc.nginx_controller) using the ansible-galaxy command.
Write a requirements file requirements.yml that ensures the collection cloud from cloudscale_ch is installed. Install the collection by using this requirements file.

Solution Task 5

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$ ansible-galaxy collection install nginxinc.nginx_controller
Process install dependency map
Starting collection install process
Installing 'nginxinc.nginx_controller:3.7.5' to '/home/ansible/techlab/collections/ansible_collections/nginxinc/nginx_controller'

$ cat requirements.yml 
collections:
- name: cloudscale_ch.cloud

$ ansible-galaxy collection install -r requirements.yml 
Process install dependency map
Starting collection install process
Installing 'cloudscale_ch.cloud:1.0.0' to '/home/ansible/techlab/collections/ansible_collections/cloudscale_ch/cloud'

Task 6

Install the collection podman from namespace containers using any of the methods you know.
Write a playbook collection.yml that runs only on the controller and uses the podman collection from the namespace containers.
The playbook should install podman on the controller and pull any podman image. Be sure to escalate privileges if needed. (Use the image quay.io/bitnami/nginx if unsure).
Use the module podman_container to start a container from the previously pulled image.
Confirm the container is up and running using sudo podman ps -l.

Solution Task 6

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$ ansible-galaxy collection install containers.podman
Process install dependency map
Starting collection install process
Installing 'containers.podman:1.1.4' to '/home/ansible/techlab/collections/ansible_collections/containers/podman'

$ cat collections.yml 
---
- name: example for using modules from a collection
  become: true
  hosts: controller
  collections:
    - containers.podman
  tasks:
    - name: install podman
      dnf:
        name: podman
        state: installed

    - name: Pull an image using the module from the collection
      podman_image:
        pull: yes
        name: quay.io/bitnami/nginx

    - name: Run nginx container
      podman_container:
        name: my_nginx_container
        image: nginx
        state: present
        publish:
          - '8080'

OR:

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$ cat collections.yml 
---
- name: example for using modules from a collection
  become: true
  hosts: controller
  tasks:
    - name: install podman
      dnf:
        name: podman
        state: installed

    - name: Pull an image using the module from the collection
      containers.podman.podman_image:
        pull: yes
        name: quay.io/bitnami/nginx

    - name: Run nginx container
      containers.podman.podman_container:
        name: my_nginx_container
        image: nginx
        state: present
        publish:
          - '8080'

This would not work, since the module podman_container is only content of the collection and not part of the ansible-base installation:

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$ cat collections.yml 
---
- name: example for using modules from a collection
  become: true
  hosts: controller
  tasks:
    - name: install podman
      dnf:
        name: podman
        state: installed

    - name: Pull an image using the module from the collection
      podman_image:
        pull: yes
        name: quay.io/bitnami/nginx

    - name: Run nginx container
      podman_container:
        name: my_nginx_container
        image: nginx
        state: present
        publish:
          - '8080'

$ ansible-playbook -i hosts collections.yml 
ERROR! couldn't resolve module/action 'podman_container'. This often indicates a misspelling, missing collection, or incorrect module path.

The error appears to be in '/home/ansible/techlab/collections.yml': line 16, column 7, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:


    - name: Run nginx container
      ^ here

Check the running container:

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$ sudo podman ps -l
CONTAINER ID  IMAGE                         COMMAND               CREATED             STATUS                 PORTS                                  NAMES
00783ec12950  quay.io/bitnami/nginx:latest  /opt/bitnami/scri...  About a minute ago  Up About a minute ago  8443/tcp, 0.0.0.0:32771->8080/tcp      my_nginx_container

You can even connect to your container using a dynamically assigned port (32771 in the example above) on your host machine. Make sure to adjust the port in the curl command-line accordingly:

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$ curl -s http://localhost:32771 | grep title
<title>Welcome to nginx!</title>

Task 7

Remove podman with an ad-hoc command to not interfere with the next labs.

Solution Task 7

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ansible localhost -b -m dnf -a"name=podman, state=absent"

All done?

What led to ansible collections and reorganization of the community?

Last modified November 20, 2023: Merge pull request #216 from puzzle/psc_edaserver_lab (d791dbe)