add configs and debug options for aws-replicator proxy container (#54)

aws-replicator/README.md

@@ -108,6 +108,13 @@ make_bucket: test123
 
 A more comprehensive sample, involving local Lambda functions combined with remote SQS queues and S3 buckets, can be found in the `example` folder of this repo.
 
+### Configuration
+
+In addition to the proxy services configuration shown above, the following configs can be used to customize the behavior of the extension itself (simply pass them as environment variables to the main LocalStack container):
+* `REPLICATOR_CLEANUP_PROXY_CONTAINERS`: whether to clean up (remove) the proxy Docker containers once they shut down (default `1`). Can be set to `0` to help debug issues, e.g., if a proxy container starts up and exits immediately.
+* `REPLICATOR_LOCALSTACK_HOST`: the target host to use when the proxy container connects to the LocalStack main container (automatically determined by default)
+* `REPLICATOR_PROXY_DOCKER_FLAGS`: additional flags that should be passed when creating the proxy Docker containers
+
 ## Resource Replicator CLI
 
 The figure below illustrates how the extension can be used to replicate the state, e.g., an SQS queue and the messages contained in it, from AWS into your LocalStack instance.
@@ -143,6 +150,9 @@ localstack extensions install "git+https://github.com/localstack/localstack-exte
 
 ## Change Log
 
+* `0.1.10`: Add `REPLICATOR_PROXY_DOCKER_FLAGS` option to pass custom flags to proxy Docker containers
+* `0.1.9`: Enhance proxy networking and add `REPLICATOR_LOCALSTACK_HOST` config option
+* `0.1.8`: Add `REPLICATOR_CLEANUP_PROXY_CONTAINERS` option to skip removing proxy containers for debugging
 * `0.1.7`: Add rolo dependency to tests
 * `0.1.6`: Adjust config to support `LOCALSTACK_AUTH_TOKEN` in addition to legacy API keys
 * `0.1.5`: Minor fix to accommodate recent upstream changes

aws-replicator/aws_replicator/client/auth_proxy.py

@@ -27,13 +27,14 @@
 from localstack.utils.docker_utils import DOCKER_CLIENT, reserve_available_container_port
 from localstack.utils.files import new_tmp_file, save_file
 from localstack.utils.functions import run_safe
-from localstack.utils.net import get_free_tcp_port
+from localstack.utils.net import get_docker_host_from_container, get_free_tcp_port
 from localstack.utils.server.http2_server import run_server
 from localstack.utils.serving import Server
 from localstack.utils.strings import short_uid, to_bytes, to_str, truncate
 from localstack_ext.bootstrap.licensingv2 import ENV_LOCALSTACK_API_KEY, ENV_LOCALSTACK_AUTH_TOKEN
 from requests import Response
 
+from aws_replicator import config as repl_config
 from aws_replicator.client.utils import truncate_content
 from aws_replicator.config import HANDLER_PATH_PROXIES
 from aws_replicator.shared.models import AddProxyRequest, ProxyConfig
@@ -142,6 +143,7 @@ def register_in_instance(self):
             raise Exception("Proxy currently not running")
         url = f"{external_service_url()}{HANDLER_PATH_PROXIES}"
         data = AddProxyRequest(port=port, config=self.config)
+        LOG.debug("Registering new proxy in main container via: %s", url)
         try:
             response = requests.post(url, json=data)
             assert response.ok
@@ -313,6 +315,7 @@ def start_aws_auth_proxy_in_container(
         entrypoint="",
         command=["bash", "-c", f"touch {CONTAINER_LOG_FILE}; tail -f {CONTAINER_LOG_FILE}"],
         ports=ports,
+        additional_flags=repl_config.PROXY_DOCKER_FLAGS,
     )
 
     # start container in detached mode
@@ -346,7 +349,13 @@ def start_aws_auth_proxy_in_container(
     ]
     env_vars = env_vars or os.environ
     env_vars = select_attributes(dict(env_vars), env_var_names)
-    env_vars["LOCALSTACK_HOST"] = "host.docker.internal"
+
+    # Determine target hostname - we make the host configurable via PROXY_LOCALSTACK_HOST,
+    #  and if not configured then use get_docker_host_from_container() as a fallback.
+    target_host = repl_config.PROXY_LOCALSTACK_HOST
+    if not repl_config.PROXY_LOCALSTACK_HOST:
+        target_host = get_docker_host_from_container()
+    env_vars["LOCALSTACK_HOST"] = target_host
 
     try:
         print("Proxy container is ready.")
@@ -379,7 +388,8 @@ def start_aws_auth_proxy_in_container(
             LOG.info("Error in called process - output: %s\n%s", e.stdout, e.stderr)
     finally:
         try:
-            DOCKER_CLIENT.remove_container(container_name, force=True)
+            if repl_config.CLEANUP_PROXY_CONTAINERS:
+                DOCKER_CLIENT.remove_container(container_name, force=True)
         except Exception as e:
             if "already in progress" not in str(e):
                 raise

aws-replicator/aws_replicator/config.py

@@ -1,5 +1,17 @@
+import os
+
+from localstack.config import is_env_not_false
 from localstack.constants import INTERNAL_RESOURCE_PATH
 
 # handler path within the internal /_localstack endpoint
 HANDLER_PATH_REPLICATE = f"{INTERNAL_RESOURCE_PATH}/aws/replicate"
 HANDLER_PATH_PROXIES = f"{INTERNAL_RESOURCE_PATH}/aws/proxies"
+
+# whether to clean up proxy containers (set to "0" to investigate startup issues)
+CLEANUP_PROXY_CONTAINERS = is_env_not_false("REPLICATOR_CLEANUP_PROXY_CONTAINERS")
+
+# additional Docker flags to pass to the proxy containers
+PROXY_DOCKER_FLAGS = (os.getenv("REPLICATOR_PROXY_DOCKER_FLAGS") or "").strip()
+
+# LS hostname to use for proxy Docker container to register itself at the main container
+PROXY_LOCALSTACK_HOST = (os.getenv("REPLICATOR_LOCALSTACK_HOST") or "").strip()

aws-replicator/aws_replicator/server/request_handler.py

@@ -19,6 +19,7 @@
 from localstack.utils.strings import to_str
 from localstack.utils.threads import start_worker_thread
 
+from aws_replicator import config as repl_config
 from aws_replicator.client.auth_proxy import (
     CONTAINER_CONFIG_FILE,
     CONTAINER_NAME_PREFIX,
@@ -145,7 +146,9 @@ def get_proxy_containers() -> List[Dict]:
 def stop_proxy_containers():
     for container in get_proxy_containers():
         try:
-            DOCKER_CLIENT.remove_container(container["name"], force=True)
+            DOCKER_CLIENT.stop_container(container["name"])
+            if repl_config.CLEANUP_PROXY_CONTAINERS:
+                DOCKER_CLIENT.remove_container(container["name"], force=True)
         except Exception as e:
             LOG.debug("Unable to remove container %s: %s", container["name"], e)
 

aws-replicator/setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = localstack-extension-aws-replicator
-version = 0.1.7
+version = 0.1.10
 summary = LocalStack Extension: AWS replicator
 description = Replicate AWS resources into your LocalStack instance
 long_description = file: README.md