Vendor Galaxy Roles and Collections

ansible_collections/community/docker/plugins/modules/current_container_facts.py

@@ -0,0 +1,148 @@
+#!/usr/bin/python
+#
+# Copyright (c) 2020 Matt Clay <mclay@redhat.com>
+# Copyright (c) 2020 Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import annotations
+
+DOCUMENTATION = r"""
+module: current_container_facts
+short_description: Return facts about whether the module runs in a container
+version_added: 1.1.0
+description:
+  - Return facts about whether the module runs in a Docker or podman container.
+  - This module attempts a best-effort detection. There might be special cases where it does not work; if you encounter one,
+    make sure that this is still a problem with the latest community.docker release, and if it is,
+    L(please file an issue, https://github.com/ansible-collections/community.docker/issues/new?assignees=&labels=&template=bug_report.md).
+author:
+  - Felix Fontein (@felixfontein)
+extends_documentation_fragment:
+  - community.docker._attributes
+  - community.docker._attributes.facts
+  - community.docker._attributes.facts_module
+  - community.docker._attributes.idempotent_not_modify_state
+"""
+
+EXAMPLES = r"""
+---
+- name: Get facts on current container
+  community.docker.current_container_facts:
+
+- name: Print information on current container when running in a container
+  ansible.builtin.debug:
+    msg: "Container ID is {{ ansible_module_container_id }}"
+  when: ansible_module_running_in_container
+"""
+
+RETURN = r"""
+ansible_facts:
+  description: Ansible facts returned by the module.
+  type: dict
+  returned: always
+  contains:
+    ansible_module_running_in_container:
+      description:
+        - Whether the module was able to detect that it runs in a container or not.
+      returned: always
+      type: bool
+    ansible_module_container_id:
+      description:
+        - The detected container ID.
+        - Contains an empty string if no container was detected.
+      returned: always
+      type: str
+    ansible_module_container_type:
+      description:
+        - The detected container environment.
+        - Contains an empty string if no container was detected, or a non-empty string identifying the container environment.
+        - V(docker) indicates that the module ran inside a regular Docker container.
+        - V(azure_pipelines) indicates that the module ran on Azure Pipelines. This seems to no longer be reported.
+        - V(github_actions) indicates that the module ran inside a Docker container on GitHub Actions. It is supported since
+          community.docker 2.4.0.
+        - V(podman) indicates that the module ran inside a regular Podman container. It is supported since community.docker
+          3.3.0.
+      returned: always
+      type: str
+      choices:
+        - ''
+        - docker
+        - azure_pipelines
+        - github_actions
+        - podman
+"""
+
+import os
+import re
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main() -> None:
+    module = AnsibleModule({}, supports_check_mode=True)
+
+    cpuset_path = "/proc/self/cpuset"
+    mountinfo_path = "/proc/self/mountinfo"
+
+    container_id = ""
+    container_type = ""
+
+    contents = None
+    if os.path.exists(cpuset_path):
+        # File content varies based on the environment:
+        #   No Container: /
+        #   Docker: /docker/c86f3732b5ba3d28bb83b6e14af767ab96abbc52de31313dcb1176a62d91a507
+        #   Azure Pipelines (Docker): /azpl_job/0f2edfed602dd6ec9f2e42c867f4d5ee640ebf4c058e6d3196d4393bb8fd0891
+        #   Podman: /../../../../../..
+        # While this was true and worked well for a long time, this seems to be no longer accurate
+        # with newer Docker / Podman versions and/or with cgroupv2. That's why the /proc/self/mountinfo
+        # detection further down is done when this test is inconclusive.
+        with open(cpuset_path, "rb") as f:
+            contents = f.read().decode("utf-8")
+
+        cgroup_path, cgroup_name = os.path.split(contents.strip())
+
+        if cgroup_path == "/docker":
+            container_id = cgroup_name
+            container_type = "docker"
+
+        if cgroup_path == "/azpl_job":
+            container_id = cgroup_name
+            container_type = "azure_pipelines"
+
+        if cgroup_path == "/actions_job":
+            container_id = cgroup_name
+            container_type = "github_actions"
+
+    if not container_id and os.path.exists(mountinfo_path):
+        with open(mountinfo_path, "rb") as f:
+            contents = f.read().decode("utf-8")
+
+        # As to why this works, see the explanations by Matt Clay in
+        # https://github.com/ansible/ansible/blob/80d2f8da02052f64396da6b8caaf820eedbf18e2/test/lib/ansible_test/_internal/docker_util.py#L571-L610
+
+        for line in contents.splitlines():
+            parts = line.split()
+            if len(parts) >= 5 and parts[4] == "/etc/hostname":
+                m = re.match(".*/([a-f0-9]{64})/hostname$", parts[3])
+                if m:
+                    container_id = m.group(1)
+                    container_type = "docker"
+
+                m = re.match(".*/([a-f0-9]{64})/userdata/hostname$", parts[3])
+                if m:
+                    container_id = m.group(1)
+                    container_type = "podman"
+
+    module.exit_json(
+        ansible_facts={
+            "ansible_module_running_in_container": container_id != "",
+            "ansible_module_container_id": container_id,
+            "ansible_module_container_type": container_type,
+        }
+    )
+
+
+if __name__ == "__main__":
+    main()