Generate a template from a resource

Setup the command line options and calls for generating
a template from an installed resource.

blueprint resource-template

Change-Id: If533bd90b1ec73bbe2603b55a0a7621879d355ec

heatclient/common/utils.py

@@ -19,11 +19,16 @@ import prettytable
 import sys
 import textwrap
 import uuid
-
+import yaml
 
 from heatclient import exc
 from heatclient.openstack.common import importutils
 
+supported_formats = {
+    "json": lambda x: json.dumps(x, indent=2),
+    "yaml": yaml.safe_dump
+}
+
 
 # Decorator for cli-args
 def arg(*args, **kwargs):
@@ -151,3 +156,13 @@ def format_parameters(params):
 
             parameters[n] = v
     return parameters
+
+
+def format_output(output, format='yaml'):
+    """Format the supplied dict as specified."""
+    output_format = format.lower()
+    try:
+        return supported_formats[output_format](output)
+    except KeyError:
+        raise exc.HTTPUnsupported("The format(%s) is unsupported."
+                                  % output_format)

heatclient/exc.py

@@ -138,6 +138,10 @@ class HTTPOverLimit(OverLimit):
     pass
 
 
+class HTTPUnsupported(HTTPException):
+    code = 415
+
+
 class HTTPInternalServerError(HTTPException):
     code = 500
 

heatclient/v1/resources.py

@@ -67,3 +67,9 @@ class ResourceManager(stacks.StackChildManager):
                                            '/stacks/%s/resources/%s/metadata' %
                                            (stack_id, resource_name))
         return body['metadata']
+
+    def generate_template(self, resource_name):
+        resp, body = self.api.json_request('GET',
+                                           '/resource_types/%s/template' %
+                                           resource_name)
+        return body

heatclient/v1/shell.py

@@ -368,6 +368,24 @@ def do_resource_show(hc, args):
         utils.print_dict(resource.to_dict(), formatters=formatters)
 
 
+@utils.arg('resource', metavar='<RESOURCE>',
+           help='Name of the resource to generate a template for.')
+@utils.arg('-F', '--format', metavar='<FORMAT>',
+           help="The template output format. %s" % utils.supported_formats)
+def do_resource_template(hc, args):
+    '''Generate a template based on a resource.'''
+    fields = {'resource_name': args.resource}
+    try:
+        template = hc.resources.generate_template(**fields)
+    except exc.HTTPNotFound:
+        raise exc.CommandError('Resource %s not found.' % args.resource)
+    else:
+        if args.format:
+            print utils.format_output(template, format=args.format)
+        else:
+            print utils.format_output(template)
+
+
 @utils.arg('id', metavar='<NAME or ID>',
            help='Name or ID of stack to show the resource metadata for.')
 @utils.arg('resource', metavar='<RESOURCE>',