Allow dependencies to be resolved automatically and merged with stack configs, resolve global deps, code cleanup

cloudbender/cli.py

@@ -126,14 +126,19 @@ def sort_stacks(ctx, stacks):
 
     data = {}
     for s in stacks:
-        # Resolve dependencies
+        # To resolve dependencies we have to read each template
+        s.read_template_file()
         deps = []
         for d in s.dependencies:
             # For now we assume deps are artifacts so we prepend them with our local profile and region to match stack.id
             for dep_stack in cb.filter_stacks({'region': s.region, 'profile': s.profile, 'provides': d}):
                 deps.append(dep_stack.id)
+            # also look for global services
+            for dep_stack in cb.filter_stacks({'region': 'global', 'profile': s.profile, 'provides': d}):
+                deps.append(dep_stack.id)
 
         data[s.id] = set(deps)
+        logger.debug("Stack {} depends on {}".format(s.id, deps))
 
     for k, v in data.items():
         v.discard(k) # Ignore self dependencies

cloudbender/jinja.py

@@ -22,6 +22,9 @@ def get_custom_att(context, att=None, ResourceName="FortyTwo", attributes={}, fl
         attributes for the specified CustomResource to include them later in
         the actual CustomResource include property """
 
+    if ResourceName not in attributes:
+        attributes[ResourceName] = set()
+
     # If flush is set all we do is empty our state dict
     if flush:
         attributes.clear()
@@ -32,21 +35,24 @@ def get_custom_att(context, att=None, ResourceName="FortyTwo", attributes={}, fl
         return attributes
 
     # If dependencies, return all Artifacts this stack depends on, which are the attr of FortyTwo
+    config = context.get_all()['_config']
     if dependencies:
         deps = set()
-        if ResourceName in attributes:
+        try:
-            for att in attributes[ResourceName]:
+            for att in attributes['FortyTwo']:
                 deps.add(att.split('.')[0])
+        except KeyError:
+            pass
+
+        # Incl. FortyTwo itself if any FortyTwo function is used
+        if config['cfn']['Mode'] == "FortyTwo" and attributes:
+            deps.add('FortyTwo')
 
         return list(deps)
     
     # If call with an attribute, return fragement and register
     if att:
-        if ResourceName not in attributes:
-            attributes[ResourceName] = set()
-
         attributes[ResourceName].add(att)
-        config = context.get_all()['_config']
         if config['cfn']['Mode'] == "FortyTwo":
             return('{{ "Fn::GetAtt": ["{0}", "{1}"] }}'.format(ResourceName, att))
         elif config['cfn']['Mode'] == "AWSImport" and ResourceName == "FortyTwo":

cloudbender/stack.py

@@ -48,6 +48,7 @@ class Stack(object):
         self.provides = template
         self.cfn_template = None
         self.cfn_parameters = []
+        self.cfn_data = None
         self.connection_manager = BotoConnection(self.profile, self.region)
         self.ctx = ctx
         self.status = None
@@ -62,7 +63,7 @@ class Stack(object):
 
     def read_config(self):
         _config = read_yaml_file(self.path)
-        for p in ["region", "stackname", "template", "dependencies", "default_lock", "multi_delete", "provides"]:
+        for p in ["region", "stackname", "template", "default_lock", "multi_delete", "provides"]:
             if p in _config:
                 setattr(self, p, _config[p])
 
@@ -76,6 +77,10 @@ class Stack(object):
         if 'vars' in _config:
             self.template_vars = dict_merge(self.template_vars, _config['vars'])
 
+        if 'dependencies' in _config:
+            for dep in _config['dependencies']:
+                self.dependencies.add(dep)
+
         logger.debug("Stack {} added.".format(self.id))
 
 
@@ -153,7 +158,7 @@ class Stack(object):
         rendered = template.render({ 'cfn': self.template_vars, 'Metadata': template_metadata })
 
         try:
-            data = yaml.load(rendered)
+            self.data = yaml.load(rendered)
         except:
             # In case we rendered invalid yaml this helps to debug
             logger.error(rendered)
@@ -162,15 +167,27 @@ class Stack(object):
         # Some sanity checks and final cosmetics
         # Check for empty top level Parameters, Outputs and Conditions and remove
         for key in ['Parameters', 'Outputs', 'Conditions']:
-            if key in data and data[key] is None:
+            if key in self.data and self.data[key] is None:
                 # Delete from data structure which also takes care of json
-                del data[key]
+                del self.data[key]
                 # but also remove from rendered for the yaml file
                 rendered = rendered.replace('\n'+key+":",'')
 
         # Condense multiple empty lines to one
         self.cfn_template = re.sub(r'\n\s*\n', '\n\n', rendered)
 
+        # Update internal data structures
+        self._parse_metadata()
+
+
+    def _parse_metadata(self):
+        # Extract dependencies if present
+        try:
+            for dep in self.data['Metadata']['CloudBender']['Dependencies']:
+                self.dependencies.add(dep)
+        except KeyError:
+            pass
+
 
     def write_template_file(self):
         if self.cfn_template:
@@ -194,20 +211,26 @@ class Stack(object):
 
 
     def read_template_file(self):
+        """ Reads rendered yaml template from disk and extracts metadata """
+        if not self.cfn_template:
             yaml_file = os.path.join(self.ctx['template_path'], self.rel_path, self.stackname+".yaml")
             with open(yaml_file, 'r') as yaml_contents:
                 self.cfn_template = yaml_contents.read()
                 logger.debug('Read cfn template %s.', yaml_file)
 
+            self.data = yaml.load(self.cfn_template)
+            self._parse_metadata()
+
+        else:
+            logger.debug('Using cached cfn template %s.', yaml_file)
+
 
     def validate(self):
         """Validates the rendered template via cfn-lint"""
-        if not self.cfn_template:
         self.read_template_file()
 
-        data = yaml.load(self.cfn_template)
         try:
-            ignore_checks = data['Metadata']['cfnlint_ignore']
+            ignore_checks = self.data['Metadata']['cfnlint_ignore']
         except KeyError:
             ignore_checks = []
 
@@ -238,11 +261,8 @@ class Stack(object):
     def resolve_parameters(self):
         """ Renders parameters for the stack based on the source template and the environment configuration """
 
-        if not self.cfn_template:
         self.read_template_file()
 
-        data = yaml.load(self.cfn_template)
-
         # Inspect all outputs of the running Conglomerate members
         # if we run in Piped Mode
         # if self.template_vars['Mode'] == "Piped":
@@ -252,9 +272,9 @@ class Stack(object):
         #     except KeyError:
          #        pass
 
-        if 'Parameters' in data:
+        if 'Parameters' in self.data:
             self.cfn_parameters = []
-            for p in data['Parameters']:
+            for p in self.data['Parameters']:
                 # In Piped mode we try to resolve all Paramters first via stack_outputs
                 #if config['cfn']['Mode'] == "Piped":
                 #    try:
@@ -274,7 +294,7 @@ class Stack(object):
                     logger.info('Got {} = {}'.format(p,value))
                 except KeyError as e:
                     # If we have a Default defined in the CFN skip, as AWS will use it
-                    if 'Default' in data['Parameters'][p]:
+                    if 'Default' in self.data['Parameters'][p]:
                         continue
                     else:
                         logger.error('Cannot find value for parameter {0}'.format(p))
@@ -310,8 +330,6 @@ class Stack(object):
         # Prepare parameters
         self.resolve_parameters()
         self.write_parameter_file()
-
-        if not self.cfn_template:
         self.read_template_file()
 
         logger.info('Creating {0} {1}'.format(self.region, self.stackname))
@@ -332,8 +350,6 @@ class Stack(object):
         # Prepare parameters
         self.resolve_parameters()
         self.write_parameter_file()
-
-        if not self.cfn_template:
         self.read_template_file()
 
         logger.info('Updating {0} {1}'.format(self.region, self.stackname))
@@ -372,8 +388,6 @@ class Stack(object):
         # Prepare parameters
         self.resolve_parameters()
         self.write_parameter_file()
-
-        if not self.cfn_template:
         self.read_template_file()
 
         logger.info('Creating change set {0} for stack {1}'.format(change_set_name, self.stackname))