Add ServiceCollection

plum/service_collection.py

@@ -0,0 +1,37 @@
+from .service import Service
+
+def sort_service_dicts(services):
+    # Sort in dependency order
+    def cmp(x, y):
+        x_deps_y = y['name'] in x.get('links', [])
+        y_deps_x = x['name'] in y.get('links', [])
+        if x_deps_y and not y_deps_x:
+            return 1
+        elif y_deps_x and not x_deps_y:
+            return -1
+        return 0
+    return sorted(services, cmp=cmp)
+
+class ServiceCollection(list):
+    @classmethod
+    def from_dicts(cls, client, service_dicts):
+        """
+        Construct a ServiceCollection from a list of dicts representing services.
+        """
+        collection = ServiceCollection()
+        for service_dict in sort_service_dicts(service_dicts):
+            # Reference links by object
+            links = []
+            if 'links' in service_dict:
+                for name in service_dict.get('links', []):
+                    links.append(collection.get(name))
+                del service_dict['links']
+            collection.append(Service(client=client, links=links, **service_dict))
+        return collection
+
+    def get(self, name):
+        for service in self:
+            if service.name == name:
+                return service
+
+

plum/tests/service_collection_test.py

@@ -0,0 +1,44 @@
+from plum.service import Service
+from plum.service_collection import ServiceCollection
+from unittest import TestCase
+
+
+class ServiceCollectionTest(TestCase):
+    def test_from_dict(self):
+        collection = ServiceCollection.from_dicts(None, [
+            {
+                'name': 'web',
+                'image': 'ubuntu'
+            },
+            {
+                'name': 'db',
+                'image': 'ubuntu'
+            }
+        ])
+        self.assertEqual(len(collection), 2)
+        web = [s for s in collection if s.name == 'web'][0]
+        self.assertEqual(web.name, 'web')
+        self.assertEqual(web.image, 'ubuntu')
+        db = [s for s in collection if s.name == 'db'][0]
+        self.assertEqual(db.name, 'db')
+        self.assertEqual(db.image, 'ubuntu')
+
+    def test_from_dict_sorts_in_dependency_order(self):
+        collection = ServiceCollection.from_dicts(None, [
+            {
+                'name': 'web',
+                'image': 'ubuntu',
+                'links': ['db'],
+            },
+            {
+                'name': 'db',
+                'image': 'ubuntu'
+            }
+        ])
+        
+        self.assertEqual(collection[0].name, 'db')
+        self.assertEqual(collection[1].name, 'web')
+
+
+
+