Add a lookup plugin for nova servers

This change adds a lookup plugin to retrieve server information from
the Nova API. Results can be filtered by server attributes.

Change-Id: Ibbac1d5ce466f8c04d773d296f935ad555f7cb4d

releasenotes/notes/add_a_lookup_plugin_for_nova_servers-33a934236e6652fb.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Adds a lookup plugin to retrieve server information from
+    the Nova API. Results can be filtered by server attributes.

requirements.txt

@@ -5,6 +5,8 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 oslo.config>=5.1.0 # Apache-2.0
 keystoneauth1>=3.3.0 # Apache-2.0
+python-novaclient>=9.1.0 # Apache-2.0
 python-heatclient>=1.10.0 # Apache-2.0
 os-net-config>=7.1.0 # Apache-2.0
+six>=1.10.0 # MIT
 tripleo-common>=7.1.0 # Apache-2.0

validations/lookup_plugins/nova_servers.py

@@ -0,0 +1,101 @@
+#!/usr/bin/env python
+
+# Copyright 2017 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.
+
+DOCUMENTATION = """
+    lookup: nova_servers
+    description: Retrieve server information from Nova
+    long_description:
+      - Load server information using the Nova API and search by attribute.
+    options:
+      _terms:
+        description: Optional filter attribute and filter value
+    author: Florian Fuchs <flfuchs@redhat.com>
+"""
+
+EXAMPLES = """
+    - name: Get all server ids from nova
+      debug:
+        msg: |
+             {{ lookup('nova_servers', wantlist=True) |
+             map(attribute='id') | join(', ') }}
+
+    - name: Lookup all server ids from nova with a certain ctlplane IP
+      debug:
+        msg: |
+             {{ lookup('nova_servers', 'ip', 'ctlplane', ['192.168.24.15'],
+             wantlist=True) | map(attribute='id') | join(', ') }}"
+
+    - name: Get server with name 'overcloud-controller-0'
+      debug:
+        msg: |
+             {{ lookup('nova_servers', 'name', ['overcloud-controller-0'],
+             wantlist=True) | map(attribute='name') }}"
+"""
+
+RETURN = """
+_raw:
+    description: A Python list with results from the API call.
+"""
+
+from ansible.plugins.lookup import LookupBase
+from novaclient import client as nova_client
+from novaclient.exceptions import NotFound
+from six import string_types
+
+from tripleo_validations.utils import get_auth_session
+
+
+class LookupModule(LookupBase):
+
+    def run(self, terms, variables=None, **kwargs):
+        """Returns server information from nova."""
+        auth_url = variables.get('auth_url')
+        username = variables.get('username')
+        project_name = variables.get('project_name')
+        token = variables.get('os_auth_token')
+        session = get_auth_session(auth_url, username, project_name,
+                                   auth_token=token)
+        nova = nova_client.Client(2, session=session)
+
+        servers = []
+        if len(terms) > 0:
+            # Look up servers by network and IP
+            if terms[0] == 'ip':
+                for ip in terms[2]:
+                    try:
+                        servers.append(nova.servers.find(
+                            networks={terms[1]: [ip]}))
+                    except NotFound:
+                        pass
+            # Look up servers by attribute
+            else:
+                for value in terms[1]:
+                    try:
+                        search_data = {terms[0]: value}
+                        servers.append(nova.servers.find(**search_data))
+                    except NotFound:
+                        pass
+        else:
+            servers = nova.servers.list()
+
+        # For each server only return properties whose value
+        # can be properly serialized. (Things like
+        # novaclient.v2.servers.ServerManager will make
+        # Ansible return the whole result as a string.)
+        return [{k: v for k, v in server.__dict__.items()
+                 if isinstance(v, (string_types, int, list, dict, type(None)))}
+                for server in servers]