From 0076adb1a6f89a6c42e0b6a0c1eec2cb4bb0f1d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Piotrowski?= <bpiotrowski@archlinux.org>
Date: Thu, 7 Dec 2017 14:09:55 +0100
Subject: [PATCH] plugins: add auto_tags plugin

---
 .gitignore                    |  1 +
 ansible.cfg                   |  1 +
 plugins/callback/auto_tags.py | 50 +++++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 plugins/callback/auto_tags.py

diff --git a/.gitignore b/.gitignore
index a8b42eb6..7d07d7f9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 *.retry
+*.pyc
diff --git a/ansible.cfg b/ansible.cfg
index 83a149e0..619aeb7b 100644
--- a/ansible.cfg
+++ b/ansible.cfg
@@ -7,6 +7,7 @@ nocows = 1
 roles_path = roles
 vault_password_file = misc/get-vault-pass.sh
 retry_files_enabled = False
+callback_plugins = plugins/callback
 callback_whitelist = profile_tasks
 
 [ssh_connection]
diff --git a/plugins/callback/auto_tags.py b/plugins/callback/auto_tags.py
new file mode 100644
index 00000000..88652092
--- /dev/null
+++ b/plugins/callback/auto_tags.py
@@ -0,0 +1,50 @@
+"""
+Source: https://gist.github.com/rkrzr/f5387167fa7b4869e2dca8b713879562
+
+This module implements an Ansible plugin that is triggered at the start of a playbook.
+
+The plugin dynamically generates a tag for each role. Each tag has the same name as its role.
+The advantage of this is that it saves you some boilerplate, because you don't have to wrap
+all tasks of a role in an additional block and assign a tag to that.
+Additionally, it works automatically when you add new roles to your playbook.
+
+Usage is exactly the same as without this plugin:
+
+ansible-playbook --tags=some_tag provision.yml
+
+Here, the "some_tag" tag was generated dynamically (assuming there is a "some_tag" role).
+
+Installation:
+1. Place this file in `plugins/callbacks/auto_tags.py` (relative to your playbook root)
+2. Add the following two lines to your `ansible.cfg` file:
+
+callback_plugins = plugins/callbacks
+callback_whitelist = auto_tags
+"""
+from __future__ import print_function
+from ansible.plugins.callback import CallbackBase
+
+
+class CallbackModule(CallbackBase):
+    """
+    Ansible supports several types of plugins. We are using the *callback* type here, since
+    it seemed the best choice for our use case, because it allows you to hook into the start
+    of a playbook.
+    """
+    def v2_playbook_on_start(self, playbook):
+        """
+        Dynamically add a tag of the same name to each role.
+        Note: Plays, roles, task_blocks and tasks can have tags.
+        """
+        plays = playbook.get_plays()
+
+        # Note: Although identical roles are shared between plays we cannot deduplicate them,
+        # since Ansible treats them as different objects internally
+        roles = [role for play in plays for role in play.get_roles()]
+
+        # Note: Tags for roles are set dynamically in `_load_role_data` instead of in __init__
+        # I don't know why they do that.
+        for role in roles:
+            role_name = role._role_name
+            if role_name not in role.tags:
+                role.tags += [role_name]