docker-ansible

docker-ansible provides ju2wheels/ansible Docker Hub images for various Linux distribution images with Ansible 1.x/2.x and core module dependencies installed from PyPi using Python 2.7 at the user level instead of at the system level so as to minimize conflicts with system Python packages.

The goal of these images is to provide a container that is capable of being used for both unit testing (by running Ansible against the local container as if it were a remote machine) as well as being suitable for use as an Ansible host.

Available Docker Image Tags

The ju2wheels/ansible Docker image tags follow the naming convention that includes the following items joined with -:

1. The Ansible major version (ie 1.x or 2.x since we always install the latest minor version for each).
2. The Linux distribution name.
3. The Linux distribution version.

1.x Docker Image Tags
1.x-alpine-3.3
1.x-alpine-3.4
1.x-alpine-3.5
1.x-alpine-3.6
1.x-alpine-3.7
1.x-alpine-3.8
1.x-amazonlinux-2016.09
1.x-amazonlinux-2017.03
1.x-amazonlinux-2017.09
1.x-amazonlinux-2017.12
1.x-amazonlinux-2018.03
1.x-centos-6
1.x-centos-7
1.x-debian-7
1.x-debian-8
1.x-debian-9
1.x-fedora-20
1.x-fedora-21
1.x-fedora-22
1.x-fedora-23
1.x-fedora-24
1.x-fedora-25
1.x-fedora-26
1.x-fedora-27
1.x-fedora-28
1.x-linuxmint-17
1.x-linuxmint-18
1.x-linuxmint-19
1.x-opensuse-42.2
1.x-opensuse-42.3
1.x-ubuntu-12.04
1.x-ubuntu-14.04
1.x-ubuntu-16.04
1.x-ubuntu-18.04

2.x Docker Image Tags
2.x-alpine-3.3
2.x-alpine-3.4
2.x-alpine-3.5
2.x-alpine-3.6
2.x-alpine-3.7
2.x-alpine-3.8
2.x-amazonlinux-2016.09
2.x-amazonlinux-2017.03
2.x-amazonlinux-2017.09
2.x-amazonlinux-2017.12
2.x-amazonlinux-2018.03
2.x-centos-6
2.x-centos-7
2.x-debian-7
2.x-debian-8
2.x-debian-9
2.x-fedora-20
2.x-fedora-21
2.x-fedora-22
2.x-fedora-23
2.x-fedora-24
2.x-fedora-25
2.x-fedora-26
2.x-fedora-27
2.x-fedora-28
2.x-linuxmint-17
2.x-linuxmint-18
2.x-linuxmint-19
2.x-opensuse-42.2
2.x-opensuse-42.3
2.x-ubuntu-12.04
2.x-ubuntu-14.04
2.x-ubuntu-16.04
2.x-ubuntu-18.04

Note: The Alpine 3.3 and 3.4 Docker images dont have shadow-utils available to them, so this has been backported from Alpine 3.5 so that the user Ansible module still works.

Organization of Dockerfiles

Each image Dockerfile has its commands organized as follows:

1. Set environment variables for PATH and any environment variables required for building the Python modules we will install.
2. System updates (update all packages that came in the base distro image).
3. Supplement repository setup.
4. Install base development tools and any packages that we want included in our images to make Ansible work.
5. Install development libraries that are required to build Python modules we want to install (including Ansible) but that we intend to remove.
6. Install pip, Ansible, and other Ansible dependencies from PyPi at the user level (root).
7. Uninstall the development libraries required to install Python modules.
8. Delete caches and temporary files.
9. Set the default entrypoint to ansible-playbook.

Note: We install Ansible at the user level instead of a virtualenv because some of the Python modules can only be installed via distro packages and not from PyPi. Therefore by installing a global Python 2.7 on the distro and those dependencies using the system packaging we can still access them by installing Ansible and all other dependencies at the user level while not cluttering up the system level Python packages or potentially crippling the system.

Using The Containers As Ansible Hosts

By default, all the images have their entrypoint configured as ansible-playbook for use as unit test containers.

In order to run the container as an Ansible host you will have to do the following:

1. Override the entrypoint to a proper shell such as /bin/bash.
2. Mount your Ansible playbook directory as a VOLUME.
3. Set the ANSIBLE_CONFIG and optionally the ANSIBLE_INVENTORY environment variables.

Using the CLI:

docker run --entrypoint /bin/bash                                   \
           --env ANSIBLE_CONFIG=/ansible-playbook/ansible.cfg       \
           --env ANSIBLE_INVENTORY=/ansible-playbook/inventory      \
           --volume '/home/user/ansible-playbook:/ansible-playbook' \
           -it ju2wheels/ansible:<tag> <ansible-playbook ARGS> <playbook.yml>

Using a docker-compose file:

version: '2'
services:
  ansible_host:
    entrypoint: /bin/bash
    environment:
      ANSIBLE_CONFIG: /ansible-playbook/ansible.cfg
      ANSIBLE_INVENTORY: /ansible-playbook/inventory
    image: ju2wheels/ansible:<tag>
    tty: true
    volumes:
      # If you place this docker-compose.yml in the root of your ansible-playbook directory
      # then you can make the volume path relative instead of absolute
      #- ./:/ansible-playbook
      - /home/user/ansible-playbook:/ansible-playbook

You can then run docker-compose:

docker-compose run ansible_host
cd /ansible-playbook
ansible-playbook my-playbook.yml

Using The Containers For Ansible Role Unit Testing

For the following unit test examples, we assume that your Ansible role meets the following conditions:

1. The role is modeled after an Ansible 2.x role as created by ansible-galaxy init, for example:

   $ ansible-galaxy init testrole
   $ find test
   testrole
   testrole/README.md
   testrole/defaults
   testrole/defaults/main.yml
   testrole/handlers
   testrole/handlers/main.yml
   testrole/meta
   testrole/meta/main.yml
   testrole/tasks
   testrole/tasks/main.yml
   testrole/tests
   testrole/tests/inventory
   testrole/tests/test.yml
   testrole/vars
   testrole/vars/main.yml
   

2. The role's tests directory has had an ansible.config and inventory added, and roles directory with a role that is relatively symlinked back to the main role directory:

   $ cd testrole/tests/
   
   $ cat <<EOF > ansible.cfg
   [default]
   # At a minimum, inventory and roles variables need to be defined
   inventory = ./inventory
   roles = ./roles
   [privilege_escalation]
   # Docker only has su available by default
   become_method=su
   EOF
   
   $ cat <<EOF > inventory
   # At a minimum, we need localhost and we need to set ansible_python_interpreter
   # because not all the Docker images default to Python 2.7 as the default Python
   localhost ansible_connection=local ansible_python_interpreter=/usr/bin/python2.7
   EOF
   
   $ mkdir roles
   $ cd roles
   $ ln -s ../.././testrole
   

Using the above role structure, all we have to do is add a docker_test.yml playbook file to our role's tests/ directory that runs the docker_container module (Ansible 2.x) or docker module (Ansible 1.x) to execute the test.yml playbook inside of one of our Docker containers.

Using Ansible 1.x docker_test.yml may look like this:

---

- hosts: localhost
  tasks:
    - name: testrole dockerized unit test
      docker: >
        command=/ansible-playbook/tests/test.yml
        detach=false
        entrypoint=ansible-playbook
        env={"ANSIBLE_CONFIG": "/ansible-playbook/tests/ansible.cfg", "ANSIBLE_INVENTORY": "/ansible-playbook/tests/inventory", "ANSIBLE_NOCOLOR": 1}
        hostname=ansible_testrole_test
        image={{ item }}
        name=ansible_testrole_test
        pull=true
        restart_policy=false
        state=started
        tty=true
        volumes=["{{ playbook_dir }}/../:/ansible-playbook"]
      with_items:
        - ju2wheels/ansible:1.x-ubuntu-12.04
        - ju2wheels/ansible:1.x-ubuntu-14.04
        - ju2wheels/ansible:1.x-ubuntu-16.04

Using Ansible 2.x docker_test.yml may look like this:

---

- hosts: localhost
  tasks:
    - name: testrole dockerized unit test
      docker_container:
        cleanup: true
        command: /ansible-playbook/tests/test.yml
        detach: false
        entrypoint: ansible-playbook
        env:
          ANSIBLE_CONFIG:    /ansible-playbook/tests/ansible.cfg
          ANSIBLE_INVENTORY: /ansible-playbook/tests/inventory
          ANSIBLE_NOCOLOR:   1
        hostname: ansible_testrole_test
        image: "{{ item }}"
        interactive: true
        name: ansible_testrole_test
        pull: true
        recreate: true
        restart_policy: false
        state: started
        tty: true
        volumes:
          - "{{ playbook_dir }}/../:/ansible-playbook"
      with_items:
        - ju2wheels/ansible:2.x-ubuntu-12.04
        - ju2wheels/ansible:2.x-ubuntu-14.04
        - ju2wheels/ansible:2.x-ubuntu-16.04

You can then run docker_test.yml to kick off your unit tests:

cd testrole/tests
ansible-playbook docker_test.yml

Note: In order to run the the unit tests, you will need the following installed on the host running the tests:

• ansible
• docker
• docker Python module (or docker-py for older versions of Docker)

See the ju2wheels.pyenv Ansible Galaxy role unit test for a more concrete example.

Note: I have tried to ensure all Ansible core module dependencies are installed in these images, however, since I can't test each individual module there may be instances where dependencies may have been missed. If you encounter a missing dependency or would like to see dependencies for commonly used third party Ansible modules, please open an issue and include the Ansible version you are using, the Docker image name, the Ansible module name, and a description of the dependencies required by that module.

Running Ansible As Another User

Since Ansible is installed at the user level, only the root user in these containers can run Ansible.

If you want to add another user under which to run Ansible you will have to copy the root user's HOME directory:

useradd -m newuser
cp -ar /root/. /home/newuser/
chown -R newuser:newuser /home/newuser
echo 'export PATH=/home/newuser/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin' >> /home/newuser/.bashrc

Contributing

Contributions of additional platforms or updates to Ansible module dependencies are welcome. Please open an issue first before submitting a PR.

License

GPLv2

Author

Julio Lajara <GH user at Gmail>