Add example of using podman collection using default driver (#3947)

Partial: #3919

.github/workflows/tox.yml

@@ -51,7 +51,7 @@ jobs:
       matrix: ${{ fromJson(needs.pre.outputs.matrix) }}
 
     env:
-      PYTEST_REQPASS: 445
+      PYTEST_REQPASS: 446
     steps:
       - uses: actions/checkout@v3
         with:

.gitignore

@@ -22,7 +22,6 @@ coverage.xml
 pip-wheel-metadata
 docs/docstree
 .docker
-molecule/**
 tools/test-schema/node_modules
 site
 .DS_Store

docs/podman.md

@@ -0,0 +1,41 @@
+# Using podman containers
+
+Below you can see a scenario that is using podman containers as test hosts.
+When you run `molecule test --scenario podman` the `create`, `converge` and
+`destroy` steps will be run one after another.
+
+This example is using Ansible playbooks and it does not need any molecule
+plugins to run. You can fully control which test requirements you need to be
+installed.
+
+## Config playbook
+
+```yaml title="molecule.yml"
+{!../molecule/podman/molecule.yml!}
+```
+
+```yaml title="requirements.yml"
+{!../molecule/podman/requirements.yml!}
+```
+
+## Create playbook
+
+```yaml title="create.yml"
+{!../molecule/podman/create.yml!}
+```
+
+```yaml title="tasks/create-fail.yml"
+{!../molecule/podman/tasks/create-fail.yml!}
+```
+
+## Converge playbook
+
+```yaml title="converge.yml"
+{!../molecule/podman/converge.yml!}
+```
+
+## Destroy playbook
+
+```yaml title="destroy.yml"
+{!../molecule/podman/destroy.yml!}
+```

mkdocs.yml

@@ -60,6 +60,8 @@ nav:
       - next.md
       - configuration.md
       - ci.md
+  - Examples:
+      - podman.md
   - examples.md
   - faq.md
   - contributing.md
@@ -88,6 +90,8 @@ plugins:
               domains: [py, std]
 
 markdown_extensions:
+  - markdown_include.include:
+      base_path: docs
   - admonition
   - def_list
   - footnotes

molecule/default/converge.yml

@@ -0,0 +1,8 @@
+---
+- name: Converge
+  hosts: all
+  gather_facts: false
+  tasks:
+    - name: Replace this task with one that validates your content
+      ansible.builtin.debug:
+        msg: "This is the effective test"

molecule/default/create.yml

@@ -0,0 +1,37 @@
+---
+- name: Create
+  hosts: localhost
+  connection: local
+  gather_facts: false
+  no_log: "{{ molecule_no_log }}"
+  tasks:
+    # TODO: Developer must implement and populate 'server' variable
+
+    - name: Create instance config
+      when: server.changed | default(false) | bool # noqa no-handler
+      block:
+        - name: Populate instance config dict # noqa jinja
+          ansible.builtin.set_fact:
+            instance_conf_dict:
+              {
+                "instance": "{{ }}",
+                "address": "{{ }}",
+                "user": "{{ }}",
+                "port": "{{ }}",
+                "identity_file": "{{ }}",
+              }
+          with_items: "{{ server.results }}"
+          register: instance_config_dict
+
+        - name: Convert instance config dict to a list
+          ansible.builtin.set_fact:
+            instance_conf: "{{ instance_config_dict.results | map(attribute='ansible_facts.instance_conf_dict') | list }}"
+
+        - name: Dump instance config
+          ansible.builtin.copy:
+            content: |
+              # Molecule managed
+
+              {{ instance_conf | to_json | from_json | to_yaml }}
+            dest: "{{ molecule_instance_config }}"
+            mode: 0600

molecule/default/destroy.yml

@@ -0,0 +1,24 @@
+---
+- name: Destroy
+  hosts: localhost
+  connection: local
+  gather_facts: false
+  no_log: "{{ molecule_no_log }}"
+  tasks:
+    # Developer must implement.
+
+    # Mandatory configuration for Molecule to function.
+
+    - name: Populate instance config
+      ansible.builtin.set_fact:
+        instance_conf: {}
+
+    - name: Dump instance config
+      ansible.builtin.copy:
+        content: |
+          # Molecule managed
+
+          {{ instance_conf | to_json | from_json | to_yaml }}
+        dest: "{{ molecule_instance_config }}"
+        mode: 0600
+      when: server.changed | default(false) | bool # noqa no-handler

molecule/default/molecule.yml

@@ -0,0 +1,6 @@
+---
+platforms:
+  - name: instance
+    # you might want to add your own variables here based on what provisioning
+    # you are doing like:
+    # image: quay.io/centos/centos:stream8

molecule/podman/converge.yml

@@ -0,0 +1,29 @@
+- name: Fail if molecule group is missing
+  hosts: localhost
+  tasks:
+    - name: Print some info
+      ansible.builtin.debug:
+        msg: "{{ groups }}"
+
+    - name: Assert group existence
+      ansible.builtin.assert:
+        that: "'molecule' in groups"
+        fail_msg: |
+          molecule group was not found inside inventory groups: {{ groups }}
+
+- name: Converge
+  hosts: molecule
+  # We disable gather facts because it would fail due to our container not
+  # having python installed. This will not prevent use from running 'raw'
+  # commands. Most molecule users are expected to use containers that already
+  # have python installed in order to avoid notable delays installing it.
+  gather_facts: false
+  tasks:
+    - name: Check uname
+      ansible.builtin.raw: uname -a
+      register: result
+      changed_when: false
+
+    - name: Print some info
+      ansible.builtin.assert:
+        that: result.stdout | regex_search("^Linux")

molecule/podman/create.yml

@@ -0,0 +1,80 @@
+- name: Create
+  hosts: localhost
+  gather_facts: false
+  vars:
+    molecule_inventory:
+      all:
+        hosts: {}
+        molecule: {}
+  tasks:
+    - name: Create a container
+      containers.podman.podman_container:
+        name: "{{ item.name }}"
+        image: "{{ item.image }}"
+        state: started
+        command: sleep 1d
+        # bash -c "while true; do sleep 10000; done"
+        log_driver: json-file
+      register: result
+      loop: "{{ molecule_yml.platforms }}"
+
+    - name: Print some info
+      ansible.builtin.debug:
+        msg: "{{ result.results }}"
+
+    - name: Fail if container is not running
+      when: >
+        item.container.State.ExitCode != 0 or
+        not item.container.State.Running
+      ansible.builtin.include_tasks:
+        file: tasks/create-fail.yml
+      loop: "{{ result.results }}"
+      loop_control:
+        label: "{{ item.container.Name }}"
+
+    - name: Add container to molecule_inventory
+      vars:
+        inventory_partial_yaml: |
+          all:
+            children:
+              molecule:
+                hosts:
+                  "{{ item.name }}":
+                    ansible_connection: containers.podman.podman
+      ansible.builtin.set_fact:
+        molecule_inventory: >
+          {{ molecule_inventory | combine(inventory_partial_yaml | from_yaml) }}
+      loop: "{{ molecule_yml.platforms }}"
+      loop_control:
+        label: "{{ item.name }}"
+
+    - name: Dump molecule_inventory
+      ansible.builtin.copy:
+        content: |
+          {{ molecule_inventory | to_yaml }}
+        dest: "{{ molecule_ephemeral_directory }}/inventory/molecule_inventory.yml"
+        mode: 0600
+
+    - name: Force inventory refresh
+      ansible.builtin.meta: refresh_inventory
+
+    - name: Fail if molecule group is missing
+      ansible.builtin.assert:
+        that: "'molecule' in groups"
+        fail_msg: |
+          molecule group was not found inside inventory groups: {{ groups }}
+      run_once: true # noqa: run-once[task]
+
+# we want to avoid errors like "Failed to create temporary directory"
+- name: Validate that inventory was refreshed
+  hosts: molecule
+  gather_facts: false
+  tasks:
+    - name: Check uname
+      ansible.builtin.raw: uname -a
+      register: result
+      changed_when: false
+
+    - name: Display uname info
+      ansible.builtin.debug:
+        msg: "{{ result.stdout }}"

molecule/podman/destroy.yml

@@ -0,0 +1,24 @@
+- name: Destroy molecule containers
+  hosts: molecule
+  gather_facts: false
+  tasks:
+    - name: Stop and remove container
+      delegate_to: localhost
+      containers.podman.podman_container:
+        name: "{{ inventory_hostname }}"
+        state: absent
+        rm: true
+    - name: Remove potentially stopped container
+      delegate_to: localhost
+      ansible.builtin.command:
+        cmd: podman container rm --ignore {{ inventory_hostname }}
+      changed_when: false
+
+- name: Remove dynamic molecule inventory
+  hosts: localhost
+  gather_facts: false
+  tasks:
+    - name: Remove dynamic inventory file
+      ansible.builtin.file:
+        path: "{{ molecule_ephemeral_directory }}/inventory/molecule_inventory.yml"
+        state: absent

molecule/podman/molecule.yml

@@ -0,0 +1,7 @@
+dependency:
+  name: galaxy
+  options:
+    requirements-file: requirements.yml
+platforms:
+  - name: molecule-ubuntu
+    image: ubuntu:18.04

molecule/podman/requirements.yml

@@ -0,0 +1,2 @@
+collections:
+  - containers.podman

molecule/podman/tasks/create-fail.yml

@@ -0,0 +1,14 @@
+- name: Retrieve container log
+  ansible.builtin.command:
+    cmd: >-
+      {% raw %}
+      podman logs
+      {% endraw %}
+      {{ item.stdout_lines[0] }}
+    # podman inspect --format='{{.HostConfig.LogConfig.Path}}'
+  changed_when: false
+  register: logfile_cmd
+
+- name: Display container log
+  ansible.builtin.fail:
+    msg: "{{ logfile_cmd.stderr }}"

src/molecule/command/login.py

@@ -96,6 +96,12 @@ def _get_login(self, hostname):  # pragma: no cover
         login_options = self._config.driver.login_options(hostname)
         login_options["columns"] = columns
         login_options["lines"] = lines
+        if not self._config.driver.login_cmd_template:
+            LOG.warning(
+                "Login command is not supported for [dim]%s[/] host because 'login_cmd_template' was not defined in driver options.",
+                login_options["instance"],
+            )
+            return
         login_cmd = self._config.driver.login_cmd_template.format(**login_options)
 
         cmd = shlex.split(f"/usr/bin/env {login_cmd}")

src/molecule/test/b_functional/test_command.py

@@ -335,3 +335,12 @@ def test_sample_collection() -> None:
         ).returncode
         == 0
     )
+
+
+def test_podman() -> None:
+    assert (
+        run_command(
+            ["molecule", "test", "--scenario-name", "podman"],
+        ).returncode
+        == 0
+    )