Added support for applying Heat Templates

Second patch expanded support to both files and dict() objects.
Third patch exposes new accessor for status and outputs.

JIRA: SNAPS-86

Change-Id: Ie7e8d883b4cc1a08dbe851fc9cbf663396334909
Signed-off-by: spisarski <s.pisarski@cablelabs.com>

1 files changed, 139 insertions, 0 deletions

diff --git a/snaps/openstack/utils/heat_utils.py b/snaps/openstack/utils/heat_utils.py
new file mode 100644
index 0000000..d40e3b9
--- /dev/null
+++ b/snaps/openstack/utils/heat_utils.py
@@ -0,0 +1,139 @@
+# Copyright (c) 2017 Cable Television Laboratories, Inc. ("CableLabs")
+#                    and others.  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 logging
+
+import yaml
+from heatclient.client import Client
+from heatclient.common.template_format import yaml_loader
+from oslo_serialization import jsonutils
+
+from snaps import file_utils
+from snaps.domain.stack import Stack
+
+from snaps.openstack.utils import keystone_utils
+
+__author__ = 'spisarski'
+
+logger = logging.getLogger('heat_utils')
+
+
+def heat_client(os_creds):
+    """
+    Retrieves the Heat client
+    :param os_creds: the OpenStack credentials
+    :return: the client
+    """
+    logger.debug('Retrieving Nova Client')
+    return Client(1, session=keystone_utils.keystone_session(os_creds))
+
+
+def get_stack_by_name(heat_cli, stack_name):
+    """
+    Returns a domain Stack object
+    :param heat_cli: the OpenStack heat client
+    :param stack_name: the name of the heat stack
+    :return: the Stack domain object else None
+    """
+    stacks = heat_cli.stacks.list(**{'name': stack_name})
+    for stack in stacks:
+        return Stack(name=stack.identifier, stack_id=stack.id)
+
+    return None
+
+
+def get_stack_by_id(heat_cli, stack_id):
+    """
+    Returns a domain Stack object for a given ID
+    :param heat_cli: the OpenStack heat client
+    :param stack_id: the ID of the heat stack to retrieve
+    :return: the Stack domain object else None
+    """
+    stack = heat_cli.stacks.get(stack_id)
+    return Stack(name=stack.identifier, stack_id=stack.id)
+
+
+def get_stack_status(heat_cli, stack_id):
+    """
+    Returns the current status of the Heat stack
+    :param heat_cli: the OpenStack heat client
+    :param stack_id: the ID of the heat stack to retrieve
+    :return:
+    """
+    return heat_cli.stacks.get(stack_id).stack_status
+
+
+def get_stack_outputs(heat_cli, stack_id):
+    """
+    Returns a domain Stack object for a given ID
+    :param heat_cli: the OpenStack heat client
+    :param stack_id: the ID of the heat stack to retrieve
+    :return: the Stack domain object else None
+    """
+    stack = heat_cli.stacks.get(stack_id)
+    return stack.outputs
+
+
+def create_stack(heat_cli, stack_settings):
+    """
+    Executes an Ansible playbook to the given host
+    :param heat_cli: the OpenStack heat client object
+    :param stack_settings: the stack configuration
+    :return: the Stack domain object
+    """
+    args = dict()
+
+    if stack_settings.template:
+        args['template'] = stack_settings.template
+    else:
+        args['template'] = parse_heat_template_str(file_utils.read_file(stack_settings.template_path))
+    args['stack_name'] = stack_settings.name
+
+    if stack_settings.env_values:
+        args['parameters'] = stack_settings.env_values
+
+    stack = heat_cli.stacks.create(**args)
+
+    return get_stack_by_id(heat_cli, stack_id=stack['stack']['id'])
+
+
+def delete_stack(heat_cli, stack):
+    """
+    Deletes the Heat stack
+    :param heat_cli: the OpenStack heat client object
+    :param stack: the OpenStack Heat stack object
+    """
+    heat_cli.stacks.delete(stack.id)
+
+
+def parse_heat_template_str(tmpl_str):
+    """Takes a heat template string, performs some simple validation and returns a dict containing the parsed structure.
+    This function supports both JSON and YAML Heat template formats.
+    """
+    if tmpl_str.startswith('{'):
+        tpl = jsonutils.loads(tmpl_str)
+    else:
+        try:
+            tpl = yaml.load(tmpl_str, Loader=yaml_loader)
+        except yaml.YAMLError as yea:
+            raise ValueError(yea)
+        else:
+            if tpl is None:
+                tpl = {}
+    # Looking for supported version keys in the loaded template
+    if not ('HeatTemplateFormatVersion' in tpl or
+            'heat_template_version' in tpl or
+            'AWSTemplateFormatVersion' in tpl):
+        raise ValueError("Template format version not found.")
+    return tpl