Handle docker python packages to support Ansible2.3+ (#151)

* Add an editorconfig file

* Revert "disable install of docker-py on 16.04+"

The issue is related to docker-compose/docker-py/docker packages messup not
to the Ubuntu version.
See: ansible/ansible#20492
The #136 PR partially fixed
it.

* Revert "Change ansible version check"

Ansible 2.3 will handle both docker and docker-py python packages.
See: ansible/ansible@e2a1ce2
and ansible/ansible#20492 (comment)

* Add a gitignore file

* Handle Docker Python packages for Ansible 2.3+

* Clean Docker Python packages

When updating to Ansible 2.3+ docker-py might no longer be needed.

* Add container tasks into the Vagrant playbook

To ensure docker modules actually work after the role installation.

.editorconfig

@@ -0,0 +1,8 @@
+root = true
+
+# default configuration
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8

.gitignore

@@ -0,0 +1,4 @@
+.vagrant/
+*.log
+env/
+venv/

README.md

@@ -91,14 +91,17 @@ docker_https_proxy:
 # Flags for whether to install pip packages
 pip_install_pip: true
 pip_install_setuptools: true
-pip_install_docker_py: true
+# pip_install_docker is ignored if pip_install_docker_compose is true as docker-compose as a dependency over docker.
+# See var/main.yml for more information.
+pip_install_docker: true
 pip_install_docker_compose: true
-install_docker_py_on_1604: false
 
 # Versions for the python packages that are installed
 pip_version_pip: latest
 pip_version_setuptools: latest
-pip_version_docker_py: latest
+# pip_version_docker is ignored if pip_install_docker_compose is true as docker-compose as a dependency over docker.
+# See var/main.yml for more information.
+pip_version_docker: latest
 pip_version_docker_compose: latest
 
 # If this variable is set to true kernel updates and host restarts are permitted.

defaults/main.yml

@@ -37,14 +37,17 @@ docker_https_proxy:
 # Flags for whether to install pip packages
 pip_install_pip: true
 pip_install_setuptools: true
-pip_install_docker_py: true
+# pip_install_docker is ignored if pip_install_docker_compose is true as docker-compose as a dependency over docker.
+# See var/main.yml for more information.
+pip_install_docker: true
 pip_install_docker_compose: true
-install_docker_py_on_1604: false
 
 # Versions for the python packages that are installed
 pip_version_pip: latest
 pip_version_setuptools: latest
-pip_version_docker_py: latest
+# pip_version_docker is ignored if pip_install_docker_compose is true as docker-compose as a dependency over docker.
+# See var/main.yml for more information.
+pip_version_docker: latest
 pip_version_docker_compose: latest
 
 # If this variable is set to true kernel updates and host restarts are permitted.

tasks/main.yml

@@ -165,6 +165,20 @@
       module in Ansible < 2.3
   when: pip_install_docker_compose and _pip_version_docker_compose != pip_version_docker_compose
 
+# See vars/main.yml for more information on this.
+- name: Clean previous docker-py package if installing docker.
+  pip:
+    name: docker-py
+    state: absent
+  when: (_pip_install_docker or pip_install_docker_compose) and _pip_docker_package_name == 'docker'
+
+# See vars/main.yml for more information on this.
+- name: Clean previous docker package if installing docker-py.
+  pip:
+    name: docker
+    state: absent
+  when: (_pip_install_docker or pip_install_docker_compose) and _pip_docker_package_name == 'docker-py'
+
 # Upgrade pip with pip to fix angstwad/docker.ubuntu/pull/35 and docker-py/issues/525
 - name: Install pip, setuptools, docker-py and docker-compose with pip
   pip:
@@ -178,9 +192,9 @@
     - name: setuptools
       version: "{{ pip_version_setuptools }}"
       install: "{{ pip_install_setuptools }}"
-    - name: docker-py
-      version: "{{ pip_version_docker_py }}"
-      install: "{{ pip_install_docker_py and (install_docker_py_on_1604 or not ansible_distribution_version|version_compare('16.04', '>=')) }}"
+    - name: "{{ _pip_docker_package_name }}"
+      version: "{{ pip_version_docker }}"
+      install: "{{ _pip_install_docker }}"
     - name: docker-compose
       version: "{{ _pip_version_docker_compose }}"
       install: "{{ pip_install_docker_compose }}"

tests/vagrant.yml

@@ -8,3 +8,19 @@
   roles:
     - role: docker.ubuntu
       kernel_update_and_reboot_permitted: yes
+
+  tasks:
+    - name: Create a dummy container
+      docker_container:
+        name: foobar
+        pull: true
+        image: busybox
+        state: started
+      when: _pip_install_docker or pip_install_docker_compose
+      register: container_creation
+
+    - name: Remove the dummy container
+      docker_container:
+        name: foobar
+        state: absent
+      when: container_creation.changed

vars/main.yml

@@ -1,8 +1,33 @@
 ---
-# Downgrade docker-compose version if ansible version < 2.3 and docker-compose > 1.9.0
-# Because of docker-compose 1.10+ requires docker python package (instead of the docker-py one)
-# which is incompatible with the docker_container module in Ansible < 2.3
+# To use Docker Ansible modules, managed nodes require some Docker Python packages :
+# * `docker-py` (renamed into `docker` since the 2.0.0 version);
+# * `docker-compose` which is required by the docker_service Ansible module.
+#
+# The `docker` python package introduces some backward incompatible changes is version 2.0.0.
+# Ansible 2.3+ is required to run this new version. Previous Ansible versions have to use docker-py<=1.10.6.
+# The `docker-compose` python package has a dependency over the docker/docker-py package.
+# The `docker-compose` 1.9.0 is the latest version to be compatible with the docker<2.0.0.
+#
+# To sum up:
+# * with Ansible < 2.3:
+#   * you have to use docker-py<=1.10.6 due to backward incompatibilities of next versions
+#   * you have to use docker-compose<=1.9.0 due to docker-compose>1.9.0 using newer versions of docker-py.
+
+# Compute the `docker` Python package's version to use.
+_pip_version_docker: >-
+    {{ '1.10.6' if ansible_version.full | version_compare('2.3', '<')
+        and (pip_version_docker=='latest' or pip_version_docker | version_compare('1.10.6', '>'))
+        else pip_version_docker }}
+
+# Compute the `docker` Python package's name according to its version.
+_pip_docker_package_name: "{{ 'docker-py' if pip_version_docker | version_compare('1.10.6', '<=') else 'docker' }}"
+
+# Determine whether to install the `docker` package or not. The `docker-compose` Python package has a dependency over the `docker` Python package.
+# So when installing the `docker-compose` package we'd rather let it handle the `docker` package version to prevent version mismatches.
+_pip_install_docker: "{{ not pip_install_docker_compose and pip_install_docker }}"
+
+# Compute the `docker-compose` Python package's version to use.
 _pip_version_docker_compose: >-
-    {{ '1.9.0' if ansible_version.full | version_compare('2.3', '<=')
+    {{ '1.9.0' if ansible_version.full | version_compare('2.3', '<')
         and (pip_version_docker_compose=='latest' or pip_version_docker_compose | version_compare('1.9.0', '>'))
         else pip_version_docker_compose }}