Ansible json error callback plugin

This callback plugin will write any task errors (that are not
ignore_error: true) to a log file in JSON format.

In later patches, we can add the cli and workflows to make these errors
visible via the Mistral API.

Change-Id: I72a91473511f335f8a0e40c7a786ff927113f26a

ansible_plugins/callback/json_error.py

@@ -0,0 +1,62 @@
+# Copyright 2018 Red Hat, Inc.
+# All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+# Ansible has another callback plugin just called "json.py", which overrides
+# a normal import of "import json", so use absolute imports
+from __future__ import absolute_import
+import json
+import os
+
+from ansible.plugins.callback import CallbackBase
+
+from tripleo_common import constants
+
+
+DOCUMENTATION = '''
+    callback: json_error
+    short_description: Write errors in JSON format to a log file
+    description:
+        - This callback writes errors in JSON format to a log file
+    type: aggregate
+    options:
+      output_dir:
+        name: json-error log file
+        default: ansible-error.json
+        description: Log file where to write errors in JSON format.
+        env:
+          - name: JSON_ERROR_LOG_FILE
+'''
+
+
+class CallbackModule(CallbackBase):
+    CALLBACK_VERSION = 2.5
+    CALLBACK_TYPE = 'aggregate'
+    CALLBACK_NAME = 'json-error'
+
+    def __init__(self, display=None):
+        super(CallbackModule, self).__init__(display)
+        self.errors = {}
+        self.log_file = os.getenv(
+            'JSON_ERROR_LOG_FILE',
+            constants.ANSIBLE_ERRORS_FILE)
+
+    def v2_playbook_on_stats(self, stats):
+        with open(self.log_file, 'w') as f:
+            f.write(json.dumps(self.errors))
+
+    def v2_runner_on_failed(self, result, ignore_errors=False):
+        if not ignore_errors:
+            host_errors = self.errors.setdefault(result._host.name, [])
+            host_errors.append((result.task_name, result._result))

setup.cfg

@@ -43,6 +43,7 @@ data_files =
     share/tripleo-common/workbooks = workbooks/*
     share/tripleo-common/healthcheck = healthcheck/*
     share/ansible/roles/ = roles/*
+    share/ansible/plugins/ = ansible_plugins/*
 
 [build_sphinx]
 source-dir = doc/source

tripleo_common/constants.py

@@ -177,3 +177,5 @@ TRIPLEO_DEPLOYMENT_RESOURCE = 'TripleODeployment'
 HOST_NETWORK = 'ctlplane'
 
 EXTERNAL_TASKS = ['external_deploy_tasks']
+
+ANSIBLE_ERRORS_FILE = 'ansible-errors.json'