feat: Add support for containers running on AWS ECS (#65)

* Add configuration entrypoint for ECS

* Instantiate RuntimeContainer based on container metadata URI

* Remove unneeded deps

* Use metadata V3 URI

judoscale/core/config.py

@@ -38,6 +38,8 @@ def initialize(cls, env: Mapping = os.environ):
             return cls.for_heroku(env)
         elif env.get("RENDER_INSTANCE_ID"):
             return cls.for_render(env)
+        elif env.get("ECS_CONTAINER_METADATA_URI"):
+            return cls.for_ecs(env)
         else:
             return cls(None, "", env)
 
@@ -55,6 +57,13 @@ def for_render(cls, env: Mapping):
         api_base_url = f"https://adapter.judoscale.com/api/{service_id}"
         return cls(runtime_container, api_base_url, env)
 
+    @classmethod
+    def for_ecs(cls, env: Mapping):
+        instance = env["ECS_CONTAINER_METADATA_URI"].split("/")[-1]
+        runtime_container = RuntimeContainer(instance)
+        api_base_url = env.get("JUDOSCALE_URL")
+        return cls(runtime_container, api_base_url, env)
+
     @property
     def is_enabled(self) -> bool:
         return bool(self["API_BASE_URL"])

tests/test_config.py

@@ -27,6 +27,20 @@ def test_on_render(self):
         assert config["LOG_LEVEL"] == "WARN"
         assert config["API_BASE_URL"] == "https://adapter.judoscale.com/api/srv-123"
 
+    def test_on_ecs(self):
+        fake_env = {
+            "ECS_CONTAINER_METADATA_URI": "http://169.254.170.2/v3/a8880ee042bc4db3ba878dce65b769b6-2750272591",  # noqa
+            "JUDOSCALE_URL": "https://adapter.judoscale.com/api/srv-123",
+            "LOG_LEVEL": "WARN",
+        }
+        config = Config.for_ecs(fake_env)
+
+        assert (
+            config["RUNTIME_CONTAINER"] == "a8880ee042bc4db3ba878dce65b769b6-2750272591"
+        )
+        assert config["LOG_LEVEL"] == "WARN"
+        assert config["API_BASE_URL"] == "https://adapter.judoscale.com/api/srv-123"
+
     def test_is_enabled(self):
         config = Config(None, "", {})
         assert not config.is_enabled