Merge pull request #3827 from mscherer/disable_callbacks

add a way for callback to disable itself

lib/ansible/callback_plugins/noop.py

@@ -21,11 +21,16 @@ class CallbackModule(object):
     """
     this is an example ansible callback file that does nothing.  You can drop
     other classes in the same directory to define your own handlers.  Methods
-    you do not use can be omitted.
+    you do not use can be omitted. If self.disabled is set to True, the plugin
+    methods will not be called.
 
     example uses include: logging, emailing, storing info, etc
     """
 
+    def __init__(self):
+        #if foo:
+        #    self.disabled = True
+        pass
 
     def on_any(self, *args, **kwargs):
         pass

lib/ansible/callbacks.py

@@ -144,6 +144,10 @@ def display(msg, color=None, stderr=False, screen_only=False, log_only=False, ru
 def call_callback_module(method_name, *args, **kwargs):
 
     for callback_plugin in callback_plugins:
+        # a plugin that set self.disabled to True will not be called
+        # see osx_say.py example for such a plugin
+        if getattr(callback_plugin, 'disabled', False):
+            continue
         methods = [
             getattr(callback_plugin, method_name, None),
             getattr(callback_plugin, 'on_any', None)

plugins/callbacks/osx_say.py

@@ -17,19 +17,28 @@
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
 import subprocess
+import os
 
 FAILED_VOICE="Zarvox"
 REGULAR_VOICE="Trinoids"
 HAPPY_VOICE="Cellos"
 LASER_VOICE="Princess"
+SAY_CMD="/usr/bin/say"
 
 def say(msg, voice):
-    subprocess.call(["/usr/bin/say", msg, "--voice=%s" % (voice)])
+    subprocess.call([SAY_CMD, msg, "--voice=%s" % (voice)])
 
 class CallbackModule(object):
     """
     makes Ansible much more exciting on OS X.
     """
+    def __init__(self):
+        # plugin disable itself if say is not present
+        # ansible will not call any callback if disabled is set to True
+        if not os.path.exists(SAY_CMD):
+            self.disabled = True
+            print "%s does not exist, plugin %s disabled" % \
+                    (SAY_CMD, os.path.basename(__file__))
 
     def on_any(self, *args, **kwargs):
         pass

test/TestCallback.py

@@ -0,0 +1,60 @@
+# (C) 2013, Michael Scherer, <misc@zarb.org>
+
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import os
+import unittest
+import subprocess
+
+# if you change here, also change in the plugin
+FILE_DISABLE = '/tmp/ansible_test_disable'
+FILE_RUN = '/tmp/ansible_test_finish'
+
+
+class TestInventory(unittest.TestCase):
+
+    def setUp(self):
+        self.cwd = os.getcwd()
+        os.chdir(os.path.join(os.path.dirname(__file__), 'test_callbacks'))
+
+    def clean_file(self):
+        if os.path.exists(FILE_RUN):
+            os.unlink(FILE_RUN)
+        if os.path.exists(FILE_DISABLE):
+            os.unlink(FILE_DISABLE)
+
+    def tearDown(self):
+        os.chdir(self.cwd)
+
+    def run_ansible_playbook(self):
+        subprocess.call('source ../../hacking/env-setup 2>&1 >/dev/null; ansible-playbook -i "127.0.0.1," test_playbook.yml 2>&1 >/dev/null', shell=True)
+
+    def test_callback(self):
+        self.clean_file()
+
+        self.run_ansible_playbook()
+        assert os.path.exists(FILE_RUN)
+        self.clean_file()
+
+    def test_callback_disabled(self):
+        self.clean_file()
+        open(FILE_DISABLE, 'w').close()
+
+        self.run_ansible_playbook()
+        assert not os.path.exists(FILE_RUN)
+
+        self.clean_file()

test/test_callbacks/callback_plugins/test_log.py

@@ -0,0 +1,27 @@
+# (C) 2013, Michael Scherer, <misc@zarb.org>
+
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+
+
+class CallbackModule(object):
+    def playbook_on_play_start(self, foo):
+        if os.path.exists('/tmp/ansible_test_disable'):
+            self.disabled = True
+
+    def playbook_on_stats(self, stats):
+            open('/tmp/ansible_test_finish', 'w').close()

test/test_callbacks/test_playbook.yml

@@ -0,0 +1,5 @@
+---
+- hosts: 127.0.0.1
+  connection: local
+  tasks:
+    shell: id