Update --template-object to support nested stacks

This patch updates heatclient so that it supports creating
stacks from an object (Swift container) which contain nested
stack relative links to nested stack URLs.

The motivation here:

We would like to be able to use heatclient to create stacks directly
from Swift containers in TripleO. The --template-object support already
exists and is great... it just needs to support loading the associated
nested stacks as well.

Change-Id: I53ac83e9f9985224d19993935467c03611aaef6a
Closes-bug: #1532326

heatclient/common/template_utils.py

@@ -30,6 +30,7 @@ def get_template_contents(template_file=None, template_url=None,
                           template_object=None, object_request=None,
                           files=None, existing=False):
 
+    is_object = False
     # Transform a bare file path to a file:// URL.
     if template_file:
         template_url = utils.normalise_file_path_to_url(template_file)
@@ -38,6 +39,7 @@ def get_template_contents(template_file=None, template_url=None,
         tpl = request.urlopen(template_url).read()
 
     elif template_object:
+        is_object = True
         template_url = template_object
         tpl = object_request and object_request('GET',
                                                 template_object)
@@ -66,11 +68,13 @@ def get_template_contents(template_file=None, template_url=None,
     tmpl_base_url = utils.base_url_for_url(template_url)
     if files is None:
         files = {}
-    resolve_template_get_files(template, files, tmpl_base_url)
+    resolve_template_get_files(template, files, tmpl_base_url, is_object,
+                               object_request)
     return files, template
 
 
-def resolve_template_get_files(template, files, template_base_url):
+def resolve_template_get_files(template, files, template_base_url,
+                               is_object=False, object_request=None):
 
     def ignore_if(key, value):
         if key != 'get_file' and key != 'type':
@@ -86,7 +90,7 @@ def resolve_template_get_files(template, files, template_base_url):
         return isinstance(value, (dict, list))
 
     get_file_contents(template, files, template_base_url,
-                      ignore_if, recurse_if)
+                      ignore_if, recurse_if, is_object, object_request)
 
 
 def is_template(file_content):
@@ -100,7 +104,8 @@ def is_template(file_content):
 
 
 def get_file_contents(from_data, files, base_url=None,
-                      ignore_if=None, recurse_if=None):
+                      ignore_if=None, recurse_if=None,
+                      is_object=False, object_request=None):
 
     if recurse_if and recurse_if(from_data):
         if isinstance(from_data, dict):
@@ -108,7 +113,8 @@ def get_file_contents(from_data, files, base_url=None,
         else:
             recurse_data = from_data
         for value in recurse_data:
-            get_file_contents(value, files, base_url, ignore_if, recurse_if)
+            get_file_contents(value, files, base_url, ignore_if, recurse_if,
+                              is_object, object_request)
 
     if isinstance(from_data, dict):
         for key, value in six.iteritems(from_data):
@@ -120,10 +126,18 @@ def get_file_contents(from_data, files, base_url=None,
 
             str_url = parse.urljoin(base_url, value)
             if str_url not in files:
-                file_content = utils.read_url_content(str_url)
+                if is_object and object_request:
+                    file_content = object_request('GET', str_url)
+                else:
+                    file_content = utils.read_url_content(str_url)
                 if is_template(file_content):
-                    template = get_template_contents(
-                        template_url=str_url, files=files)[1]
+                    if is_object:
+                        template = get_template_contents(
+                            template_object=str_url, files=files,
+                            object_request=object_request)[1]
+                    else:
+                        template = get_template_contents(
+                            template_url=str_url, files=files)[1]
                     file_content = jsonutils.dumps(template)
                 files[str_url] = file_content
             # replace the data value with the normalised absolute URL

heatclient/tests/unit/test_template_utils.py

@@ -493,6 +493,33 @@ class TestGetTemplateContents(testtools.TestCase):
         self.assertEqual({}, files)
         self.assertTrue(self.object_requested)
 
+    def test_get_nested_stack_template_contents_object(self):
+        tmpl = ('{"heat_template_version": "2016-04-08",'
+                '"resources": {'
+                '"FooBar": {'
+                '"type": "foo/bar.yaml"}}}')
+        url = 'http://no.where/path/to/a.yaml'
+        self.m.ReplayAll()
+
+        self.object_requested = False
+
+        def object_request(method, object_url):
+            self.object_requested = True
+            self.assertEqual('GET', method)
+            self.assertTrue(object_url.startswith("http://no.where/path/to/"))
+            if object_url == url:
+                return tmpl
+            else:
+                return '{"heat_template_version": "2016-04-08"}'
+
+        files, tmpl_parsed = template_utils.get_template_contents(
+            template_object=url,
+            object_request=object_request)
+
+        self.assertEqual(files['http://no.where/path/to/foo/bar.yaml'],
+                         '{"heat_template_version": "2016-04-08"}')
+        self.assertTrue(self.object_requested)
+
     def check_non_utf8_content(self, filename, content):
         base_url = 'file:///tmp'
         url = '%s/%s' % (base_url, filename)