localstack · joe4dev · Dec 23, 2022 · Dec 20, 2022 · Dec 22, 2022 · Dec 22, 2022
diff --git a/localstack/config.py b/localstack/config.py
@@ -646,6 +646,11 @@ def in_docker():
     os.environ.get("LAMBDA_REMOVE_CONTAINERS", "").lower().strip() not in FALSE_STRINGS
 )
 
+# DEV | Only for LS developers. Only applicable to new Lambda provider.
+# whether to explicitly expose port in lambda container when invoking functions in host mode for systems that cannot
+# reach the container via its IPv4 (e.g., macOS https://docs.docker.com/desktop/networking/#i-cannot-ping-my-containers)
+LAMBDA_DEV_PORT_EXPOSE = is_env_true("LAMBDA_DEV_PORT_EXPOSE")
+
 # Adding Stepfunctions default port
 LOCAL_PORT_STEPFUNCTIONS = int(os.environ.get("LOCAL_PORT_STEPFUNCTIONS") or 8083)
 # Stepfunctions lambda endpoint override
@@ -778,6 +783,7 @@ def in_docker():
     "LAMBDA_JAVA_OPTS",
     "LAMBDA_REMOTE_DOCKER",
     "LAMBDA_REMOVE_CONTAINERS",
+    "LAMBDA_DEV_PORT_EXPOSE",
     "LAMBDA_RUNTIME_EXECUTOR",
     "LAMBDA_RUNTIME_ENVIRONMENT_TIMEOUT",
     "LAMBDA_STAY_OPEN_MODE",

diff --git a/localstack/services/awslambda/invocation/docker_runtime_executor.py b/localstack/services/awslambda/invocation/docker_runtime_executor.py
@@ -10,6 +10,7 @@
 from localstack.aws.api.lambda_ import PackageType, Runtime
 from localstack.services.awslambda import hooks as lambda_hooks
 from localstack.services.awslambda.invocation.executor_endpoint import (
+    INVOCATION_PORT,
     ExecutorEndpoint,
     ServiceEndpoint,
 )
@@ -25,10 +26,12 @@
 from localstack.services.awslambda.packages import awslambda_runtime_package
 from localstack.utils.container_utils.container_client import (
     ContainerConfiguration,
+    PortMappings,
     VolumeBind,
     VolumeMappings,
 )
 from localstack.utils.docker_utils import DOCKER_CLIENT as CONTAINER_CLIENT
+from localstack.utils.net import get_free_tcp_port
 from localstack.utils.strings import truncate
 
 LOG = logging.getLogger(__name__)
@@ -249,7 +252,11 @@ def start(self, env_vars: dict[str, str]) -> None:
 
         if not container_config.image_name:
             container_config.image_name = self.get_image()
-
+        if config.LAMBDA_DEV_PORT_EXPOSE:
+            self.executor_endpoint.container_port = get_free_tcp_port()
+            if container_config.ports is None:
+                container_config.ports = PortMappings()
+            container_config.ports.add(self.executor_endpoint.container_port, INVOCATION_PORT)
         CONTAINER_CLIENT.create_container_from_config(container_config)
         if (
             not config.LAMBDA_PREBUILD_IMAGES
@@ -267,6 +274,8 @@ def start(self, env_vars: dict[str, str]) -> None:
         self.ip = CONTAINER_CLIENT.get_container_ipv4_for_network(
             container_name_or_id=self.id, container_network=network
         )
+        if config.LAMBDA_DEV_PORT_EXPOSE:
+            self.ip = "127.0.0.1"
         self.executor_endpoint.container_address = self.ip
 
     def stop(self) -> None:

diff --git a/localstack/services/awslambda/invocation/executor_endpoint.py b/localstack/services/awslambda/invocation/executor_endpoint.py
@@ -29,6 +29,7 @@ def __init__(self, message):
 class ExecutorEndpoint:
     service_endpoint: ServiceEndpoint
     container_address: str
+    container_port: int
     rules: list[Rule]
     endpoint_id: str
     router: Router
@@ -38,9 +39,11 @@ def __init__(
         endpoint_id: str,
         service_endpoint: ServiceEndpoint,
         container_address: Optional[str] = None,
+        container_port: Optional[int] = INVOCATION_PORT,
     ) -> None:
         self.service_endpoint = service_endpoint
         self.container_address = container_address
+        self.container_port = container_port
         self.rules = []
         self.endpoint_id = endpoint_id
         self.router = ROUTER
@@ -118,7 +121,7 @@ def shutdown(self) -> None:
     def invoke(self, payload: Dict[str, str]) -> None:
         if not self.container_address:
             raise ValueError("Container address not set, but got an invoke.")
-        invocation_url = f"http://{self.container_address}:{INVOCATION_PORT}/invoke"
+        invocation_url = f"http://{self.container_address}:{self.container_port}/invoke"
         response = requests.post(url=invocation_url, json=payload)
         if not response.ok:
             raise InvokeSendError(