Docker inventory plugin (#61)

* Began with docker inventory plugin.

* Linting.

* Improve plugin, add basic unit tests.

* Linting.

* Add integration test.

* Adjust tests to case that there are more containers.

* There can be stopped containers.

ci_coverage

* docker -> docker_containers

tests/integration/targets/inventory_docker_containers/playbooks/docker_cleanup.yml

@@ -0,0 +1,22 @@
+---
+- hosts: 127.0.0.1
+  connection: local
+  gather_facts: yes
+  tasks:
+    - name: remove docker containers
+      docker_container:
+        name: "{{ item }}"
+        state: absent
+        force_kill: yes
+      loop:
+        - ansible-test-docker-inventory-container-1
+        - ansible-test-docker-inventory-container-2
+
+    - name: remove docker pagkages
+      action: "{{ ansible_facts.pkg_mgr }}"
+      args:
+        name:
+          - docker
+          - docker-ce
+          - docker-ce-cli
+        state: absent

tests/integration/targets/inventory_docker_containers/playbooks/docker_setup.yml

@@ -0,0 +1,22 @@
+---
+- hosts: 127.0.0.1
+  connection: local
+  vars:
+    docker_skip_cleanup: yes
+
+  tasks:
+    - name: Setup docker
+      import_role:
+        name: setup_docker
+
+    - name: Start containers
+      docker_container:
+        name: "{{ item.name }}"
+        image: "{{ docker_test_image_alpine }}"
+        state: started
+        command: '/bin/sh -c "sleep 10m"'
+        published_ports:
+          - 22/tcp
+      loop:
+        - name: ansible-test-docker-inventory-container-1
+        - name: ansible-test-docker-inventory-container-2

tests/integration/targets/inventory_docker_containers/playbooks/test_inventory_1.yml

@@ -0,0 +1,36 @@
+---
+- hosts: 127.0.0.1
+  connection: local  # otherwise Ansible will complain that it cannot connect via ssh to 127.0.0.1:22
+  gather_facts: no
+  tasks:
+    - name: Show all groups
+      debug:
+        var: groups
+    - name: Make sure that the default groups are there, but no others
+      assert:
+        that:
+          - groups.all | length >= 2
+          - groups.ungrouped | length >= 2
+          - groups | length == 2
+
+- hosts: all
+  gather_facts: false
+  tasks:
+    - when:
+        # When the integration tests are run inside a docker container, there
+        # will be other containers.
+        - inventory_hostname.startswith('ansible-test-docker-inventory-container-')
+      block:
+
+      - name: Run raw command
+        raw: ls /
+        register: output
+
+      - name: Check whether we have some directories we expect in the output
+        assert:
+          that:
+            - "'bin' in output.stdout_lines"
+            - "'dev' in output.stdout_lines"
+            - "'lib' in output.stdout_lines"
+            - "'proc' in output.stdout_lines"
+            - "'sys' in output.stdout_lines"

tests/integration/targets/inventory_docker_containers/playbooks/test_inventory_2.yml

@@ -0,0 +1,45 @@
+---
+- hosts: 127.0.0.1
+  connection: local  # otherwise Ansible will complain that it cannot connect via ssh to 127.0.0.1:22
+  gather_facts: no
+  tasks:
+    - name: Show all groups
+      debug:
+        var: groups
+    - name: Load variables
+      include_vars: ../../setup_docker/vars/main.yml
+    - name: Make sure that the expected groups are there
+      assert:
+        that:
+          - groups.all | length >= 2
+          - groups.ungrouped | length >= 0
+          - groups.running | length >= 2
+          - groups.stopped | length >= 0
+          - groups['image_' ~ docker_test_image_alpine] | length == 2
+          - groups['ansible-test-docker-inventory-container-1'] | length == 1
+          - groups['ansible-test-docker-inventory-container-2'] | length == 1
+          - groups['unix://var/run/docker.sock'] | length >= 2
+          - groups | length >= 12
+          # The four additional groups are IDs and short IDs of the containers.
+          # When the integration tests are run inside a docker container, there
+          # will be more groups (for the additional container(s)).
+
+- hosts: all
+  # We don't really want to connect to the nodes, since we have no SSH daemon running on them
+  connection: local
+  vars:
+    ansible_python_interpreter: "{{ ansible_playbook_python }}"
+  gather_facts: no
+  tasks:
+    - name: Show all variables
+      debug:
+        var: hostvars[inventory_hostname]
+    - name: Make sure SSH is set up
+      assert:
+        that:
+          - ansible_ssh_host == '1.2.3.4'
+          - ansible_ssh_port == docker_networksettings.Ports['22/tcp'][0].HostPort
+      when:
+        # When the integration tests are run inside a docker container, there
+        # will be other containers.
+        - inventory_hostname.startswith('ansible-test-docker-inventory-container-')