Added support for restart basing on service dependencies. (Fixes sign…

…alfx#186)

maestro/plays/__init__.py

@@ -58,6 +58,9 @@ def __init__(self, containers=[], forward=True, ignore_dependencies=False,
         self._dependencies = dict(
             (c.name, self._gather_dependencies(c)) for c in containers)
 
+        self._start_dependencies = dict(
+            (c.name, self._gather_restart_dependencies(c)) for c in containers)
+
         self._om = termoutput.OutputManager(len(containers))
         self._threads = set([])
         self._done = set([])
@@ -85,8 +88,13 @@ def act(task):
             # Wait until we can be released (or if an error occurred for
             # another container).
             self._cv.acquire()
-            while not self._satisfied(task.container) and not self._error:
-                self._cv.wait(1)
+            if self._play != 'restart':
+                while not self._satisfied(task.container) and not self._error:
+                    self._cv.wait(1)
+            else:
+                while not self._restart_satisfied(task.container) and not self._error:
+                    self._cv.wait(1)
+
             self._cv.release()
 
             # Abort if needed
@@ -178,6 +186,19 @@ def _gather_dependencies(self, container):
         result.remove(container)
         return result
 
+    def _gather_restart_dependencies(self, container):
+        containers = set(self._containers)
+        result = set([container])
+
+        for container in result:
+            deps = container.service.needed_for if self._forward else container.service.requires
+            deps = functools.reduce(lambda x, y: x.union(y), [s.containers for s in deps], set([]))
+
+            result = result.union(deps.intersection(containers))
+
+        result.remove(container)
+        return result
+
     def _satisfied(self, container):
         """Returns True if all the dependencies of a given container have been
         satisfied by what's been executed so far (or if it was explicitely
@@ -187,6 +208,12 @@ def _satisfied(self, container):
         missing = self._dependencies[container.name].difference(self._done)
         return len(missing) == 0
 
+    def _restart_satisfied(self, container):
+        if self._ignore_dependencies:
+            return True
+        missing = self._start_dependencies[container.name].difference(self._done)
+        return len(missing) == 0
+
 
 class FullStatus(BaseOrchestrationPlay):
     """A Maestro orchestration play that displays the status of the given