Add the ara_read module

ara_read is an Ansible module to read data that was previously
recorded by ara_record within the same playbook context.

Change-Id: I187edcb514d812d02718124018c80e6b8c7248e8

ara/plugins/actions/ara_read.py

@@ -0,0 +1,135 @@
+#   Copyright 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.
+#
+
+import json
+import os
+
+from ansible.plugins.action import ActionBase
+
+try:
+    from ara import app, models
+    HAS_ARA = True
+except ImportError:
+    HAS_ARA = False
+
+DOCUMENTATION = '''
+---
+module: ara_read
+short_description: Ansible module to read recorded persistent data with ARA.
+version_added: "2.0"
+author: "RDO Community <rdo-list@redhat.com>"
+description:
+    - Ansible module to read recorded persistent data with ARA.
+options:
+    key:
+        description:
+            - Name of the key to read from
+        required: true
+
+requirements:
+    - "python >= 2.6"
+    - "ara >= 0.10.0"
+'''
+
+EXAMPLES = '''
+# Write data
+- ara_record:
+    key: "foo"
+    value: "bar"
+
+# Read data
+- ara_read:
+    key: "foo"
+  register: foo
+
+# Use data
+- debug:
+    msg: "{{ item }}""
+  with_items:
+    - foo.key
+    - foo.value
+    - foo.playbook_id
+'''
+
+
+class ActionModule(ActionBase):
+    ''' Read from recorded persistent data as key/value pairs in ARA '''
+
+    TRANSFERS_FILES = False
+    VALID_ARGS = frozenset(('key',))
+
+    def get_key(self, playbook_id, key):
+        try:
+            data = (models.Data.query
+                    .filter_by(key=key)
+                    .filter_by(playbook_id=playbook_id)
+                    .one())
+        except models.NoResultFound:
+            return False
+
+        return data
+
+    def run(self, tmp=None, task_vars=None):
+        if task_vars is None:
+            task_vars = dict()
+
+        if not HAS_ARA:
+            result = {
+                "failed": True,
+                "msg": "ARA is required to run this module."
+            }
+            return result
+
+        for arg in self._task.args:
+            if arg not in self.VALID_ARGS:
+                result = {
+                    "failed": True,
+                    "msg": "'{0}' is not a valid option.".format(arg)
+                }
+                return result
+
+        result = super(ActionModule, self).run(tmp, task_vars)
+
+        key = self._task.args.get('key', None)
+
+        required = ['key']
+        for parameter in required:
+            if not self._task.args.get(parameter):
+                result['failed'] = True
+                result['msg'] = "{} parameter is required".format(parameter)
+                return result
+
+        # Retrieve the persisted playbook_id from tmpfile
+        tmpfile = os.path.join(app.config['ARA_TMP_DIR'], 'ara.json')
+        with open(tmpfile) as file:
+            data = json.load(file)
+        playbook_id = data['playbook']['id']
+
+        try:
+            data = self.get_key(playbook_id, key)
+            if data:
+                result['key'] = data.key
+                result['value'] = data.value
+                result['playbook_id'] = data.playbook_id
+            msg = "Sucessfully read data for the key {0}".format(data.key)
+            result['msg'] = msg
+        except Exception as e:
+            result['key'] = None
+            result['value'] = None
+            result['playbook_id'] = None
+            result['failed'] = True
+            msg = "Could not read data for key {0}: {1}".format(key, str(e))
+            result['msg'] = msg
+        return result