Allow ansible-init to execute remote playbooks from metadata (#194)

ansible/roles/linux-ansible-init/files/ansible-init.py

@@ -0,0 +1,105 @@
+#!/usr/lib/ansible-init/bin/python
+
+import json
+import logging
+import os
+import pathlib
+import subprocess
+
+import requests
+
+
+logging.basicConfig(level = logging.INFO, format = "[%(levelname)s] %(message)s")
+
+
+logger = logging.getLogger(__name__)
+
+
+def assemble_list(data, prefix):
+    """
+    Assembles a list of items based on keys in data with the format "<prefix>_<idx>_<key>".
+    """
+    list_items = {}
+    for key, value in data.items():
+        if not key.startswith(prefix):
+            continue
+        idx, item_key = key.removeprefix(prefix).split("_", maxsplit = 1)
+        list_items.setdefault(idx, {})[item_key] = value
+    return [list_items[k] for k in sorted(list_items.keys())]
+
+
+def ansible_exec(cmd, *args, **kwargs):
+    """
+    Execute an Ansible command with the appropriate environment.
+    """
+    environ = os.environ.copy()
+    environ["ANSIBLE_CONFIG"] = "/etc/ansible-init/ansible.cfg"
+    cmd = f"/usr/lib/ansible-init/bin/ansible-{cmd}"
+    subprocess.run([cmd, *args], env = environ, check = True, **kwargs)
+
+
+logger.info("fetching instance metadata")
+METADATA_URL = "http://169.254.169.254/openstack/latest/meta_data.json"
+response = requests.get(METADATA_URL)
+response.raise_for_status()
+user_metadata = response.json().get("meta", {})
+
+
+logger.info("extracting collections and playbooks from metadata")
+collections = assemble_list(user_metadata, "ansible_init_coll_")
+playbooks = assemble_list(user_metadata, "ansible_init_pb_")
+logger.info(f"  found {len(collections)} collections")
+logger.info(f"  found {len(playbooks)} playbooks")
+
+
+logger.info("installing collections")
+ansible_exec(
+    "galaxy",
+    "collection",
+    "install",
+    "--force",
+    "--requirements-file",
+    "/dev/stdin",
+    input = json.dumps({ "collections": collections }).encode()
+)
+
+
+logger.info("executing remote playbooks for stage - pre")
+for playbook in playbooks:
+    if playbook.get("stage", "post") == "pre":
+        logger.info(f"  executing playbook - {playbook['name']}")
+        ansible_exec(
+            "playbook",
+            "--connection",
+            "local",
+            "--inventory",
+            "127.0.0.1,",
+            playbook["name"]
+        )
+
+
+logger.info("executing playbooks from /etc/ansible-init/playbooks")
+for playbook in sorted(pathlib.Path("/etc/ansible-init/playbooks").glob("*.yml")):
+    logger.info(f"  executing playbook - {playbook}")
+    ansible_exec(
+        "playbook",
+        "--connection",
+        "local",
+        "--inventory",
+        "127.0.0.1,",
+        str(playbook)
+    )
+
+
+logger.info("executing remote playbooks for stage - post")
+for playbook in playbooks:
+    if playbook.get("stage", "post") == "post":
+        logger.info(f"  executing playbook - {playbook['name']}")
+        ansible_exec(
+            "playbook",
+            "--connection",
+            "local",
+            "--inventory",
+            "127.0.0.1,",
+            playbook["name"]
+        )

ansible/roles/linux-ansible-init/files/ansible.cfg

@@ -0,0 +1,3 @@
+[defaults]
+home = /var/lib/ansible-init
+local_tmp = /var/tmp/ansible-init

ansible/roles/linux-ansible-init/tasks/main.yml

@@ -1,29 +1,40 @@
 ---
 
-- name: Install pip
+- name: Install python3-venv
   package:
-    name: python3-pip
-    state: latest
-
-- name: Upgrade pip
-  pip:
-    name: pip
-    state: latest
+    name: python3-venv
 
-- name: Install Ansible
+- name: Install dependencies into virtualenv
   pip:
     name:
       - ansible
       - jmespath
+      - requests
     state: latest
+    virtualenv: /usr/lib/ansible-init
+    virtualenv_command: python3 -m venv --upgrade-deps
+
+- name: Ensure config directories exist
+  file:
+    state: directory
+    path: "/etc/ansible-init/{{ item }}"
+  loop:
+    - vars
+    - playbooks
+    - includes
+
+- name: Install Ansible config file
+  copy:
+    src: ansible.cfg
+    dest: /etc/ansible-init/ansible.cfg
 
 - name: Install ansible-init script
   copy:
-    src: ansible-init.sh
+    src: ansible-init.py
     dest: /usr/bin/ansible-init
     mode: +x
 
-- name: Install systemd unit for ansible-init
+- name: Install systemd unit file
   copy:
     src: ansible-init.service
     dest: /etc/systemd/system/ansible-init.service