Add heat template for restarting a stack

Use mistral workflow for checking status of the given stack and
recreate stack, if VM that belongs to the stack in ERROR state or
doesn't exist. Note that it is needed to allow trusts delegation in
heat for successfull creation of a trust context.

Change-Id: I0b61177539c332db0833114e29eee7c74f2ff673

hot/mistral/templates/stack_restarter.yaml

@@ -0,0 +1,71 @@
+heat_template_version: 2015-04-30
+
+description: >
+  This template creates a stack that will observe the status of some VM
+  in the given stack. If VM has ERROR status or doesn't exist, the stack with
+  VM will be recreated. VM id status of which is needed to check obtained from
+  observed stack outputs.
+  Run "heat resource-signal <stack name> <workflow name>" for staring execution,
+  where resource name is tne name of workflow in the created stack.
+
+
+parameters:
+  stack_name:
+    type: string
+    description: Name of the stack with VM status of which is needed to check.
+
+  output_name:
+    type: string
+    description: Name of output that contains id of VM status of which is needed to check.
+    default: vm_id
+
+  pause:
+    type: number
+    description: Number of seconds to wait before status checks.
+    default: 30
+
+resources:
+  workflow:
+    type: OS::Mistral::Workflow
+    properties:
+      type: direct
+      tasks:
+        - name: get_template
+          action: heat.stacks_template stack_id=<% $.stack_name %>
+          publish:
+            template: <% $.get_template %>
+          on_success:
+            - get_vm_id
+        - name: get_vm_id
+          action: heat.stacks_get stack_id=<% $.stack_name %>
+          publish:
+              vm_id: {list_join: ["", ['<% $.get_vm_id.outputs.where($.output_key="', {get_param: output_name}, '").first().output_value %>']]}
+          on_success:
+            - get_vm_status
+        - name: get_vm_status
+          action: nova.servers_get server=<% $.vm_id %>
+          on_error:
+            - delete_stack
+          on_success:
+            - delete_stack: <% $.get_vm_status.status = ERROR %>
+            - get_vm_status: <% $.get_vm_status.status != ERROR %>
+          wait_before: { get_param: pause }
+        - name: delete_stack
+          action: heat.stacks_delete stack_id=<% $.stack_name %>
+          on_success:
+            - recreate_stack
+        - name: recreate_stack
+          action: heat.stacks_create stack_name=<% $.stack_name %> template=<% $.template %>
+          retry:
+             delay: 5
+             count: 10
+          on_success:
+            - wait_stack_complete
+        - name: wait_stack_complete
+          action: heat.stacks_get stack_id=<% $.stack_name %>
+          wait_before: 5
+          on_success:
+           - wait_stack_complete: <% $.wait_stack_complete.stack_status=CREATE_IN_PROGRESS %>
+           - get_vm_id: <% $.wait_stack_complete.stack_status=CREATE_COMPLETE %>
+      input:
+        stack_name: {get_param: stack_name}