concurrency sample

Author: MEPalma

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/.vscode/launch.json

@@ -0,0 +1,21 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Python: Remote Attach",
+            "type": "debugpy",
+            "request": "attach",
+            "connect": {
+                "host": "localhost",
+                "port": 19891
+            },
+            "pathMappings": [
+                {
+                    "localRoot": "${workspaceFolder}",
+                    "remoteRoot": "."
+                }
+            ]
+        }
+    ]
+}
+

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/Makefile

@@ -0,0 +1,20 @@
+export AWS_ACCESS_KEY_ID ?= test
+export AWS_SECRET_ACCESS_KEY ?= test
+export AWS_DEFAULT_REGION = us-east-1
+VENV_DIR ?= .venv
+
+usage:       ## Show this help
+	@fgrep -h "##" $(MAKEFILE_LIST) | fgrep -v fgrep | sed -e 's/\\$$//' | sed -e 's/##//'
+
+install:     ## Install dependencies
+	@which awslocal || pip install awscli-local
+	test -e $(VENV_DIR) || virtualenv $(VENV_DIR)
+	. $(VENV_DIR)/bin/activate; pip install debugpy
+
+run:         ## Deploy and invoke the Lambda container locally
+	echo "Deploying Lambda locally"; \
+	./run.sh; \
+	echo "Done - test successfully finished."
+
+.PHONY: usage install run
+

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/README.md

@@ -0,0 +1,57 @@
+# LocalStack Demo: Lambda Debug Mode Automatically Handle Concurrent Function Invocations
+
+A simple demo application showcasing how to Lambda Debug Mode automatically controls concurrent lambda call invocations.
+The demo deploys a Lambda function with a one-second timeout, and continues to invoke this function
+three times. Upon connecting the remote debugger, the user should see how only the first call is received and can be
+debugged, with concurrency error messages being logged about the following two invocations.
+
+## Prerequisites
+
+* LocalStack
+* Docker
+* `make`
+* [`awslocal`](https://github.com/localstack/awscli-local)
+
+## Installing
+
+To install the dependencies:
+```
+make install
+```
+
+## Starting Up
+
+Make sure that LocalStack is started with the following configuration:
+```
+LAMBDA_DEBUG_MODE=1 \
+LAMBDA_DEBUG_MODE_CONFIG_PATH=path/to/lambda_debug_mode_config.yaml \
+localstack start
+```
+
+Lambda Debug Mode is enabled through the config option `LAMBDA_DEBUG_MODE=1`.
+
+The config option `LAMBDA_DEBUG_MODE_CONFIG_PATH` should point to the provided `yaml` config file for Lambda Debug Mode `lambda_debug_mode_config.yaml`.
+The config file contains instructions for Lambda Debug Mode to debug the Lambda function `arn:aws:lambda:us-east-1:000000000000:function:function-one` on port `19891`.
+
+
+## Running the Sample
+
+The project ships with a Visual Studio Code debug launch config (see `.vscode/launch.json`). This configuration can be used to attach to the code in the Lambda function while it is executing.
+
+The following command used to deploy and invoke the Lambda locally:
+
+```
+make run
+```
+
+### Attaching the VSCode Debugger
+
+After the Lambda function is invoked you can switch to Visual Studio Code, set a breakpoint in the Lambda handler, and run the preconfigured remote debugger.
+LocalStack will automatically waive the set one second timeout for the Lambda function, giving you ample time to connect the debugger and debug the logic in the function.
+You should also notice how the debugger connects to the first invocation (the message object would end with `Attempt 1`), whilst the following invocations
+are refused automatically by Lambda Debug Mode as explained in the corresponding log messages.
+
+## License
+
+The code in this sample is available under the Apache 2.0 license.
+

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/handler.py

@@ -0,0 +1,35 @@
+def handler(event, context):
+    """Lambda handler that will get invoked by the LocalStack runtime"""
+
+    # Wait for the debugger to get attached.
+    wait_for_debug_client()
+
+    # Print the incoming invocation event.
+    print(event)
+
+    # Return the incoming invocation event.
+    return event
+
+
+def wait_for_debug_client(timeout=15):
+    """Utility function to enable debugging with Visual Studio Code"""
+    import time, threading
+    import sys, glob
+    sys.path.append(glob.glob(".venv/lib/python*/site-packages")[0])
+    import debugpy
+
+    debugpy.listen(("0.0.0.0", 19891))
+    class T(threading.Thread):
+        daemon = True
+        def run(self):
+            time.sleep(timeout)
+            print("Canceling debug wait task ...")
+            debugpy.wait_for_client.cancel()
+    T().start()
+    print("Waiting for client to attach debugger ...")
+    debugpy.wait_for_client()
+
+
+if __name__ == "__main__":
+    handler({}, {})
+

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/lambda_debug_mode_config.yaml

@@ -0,0 +1,4 @@
+functions:
+  arn:aws:lambda:us-east-1:000000000000:function:function-one:
+    debug-port: 19891
+

lambda-debug-mode/python/base-concurrent-lambda-debug-mode/run.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+#
+# Set the name of the Lambda function.
+FUNCTION_NAME="function-one"
+
+# Create the Lambda function 'function-one' through hot-reload with one second timeout.
+echo "Creating Lambda function $FUNCTION_NAME through hot-reload with one second timeout."
+awslocal lambda create-function \
+    --function-name "$FUNCTION_NAME"\
+    --timeout 1 \
+    --code "S3Bucket=hot-reload,S3Key=$(pwd)/" \
+    --handler handler.handler \
+    --role arn:aws:iam::000000000000:role/test-role \
+    --runtime python3.9
+
+# Function to check the status of the Lambda function.
+check_lambda_status() {
+    status=$(awslocal lambda get-function --function-name "$FUNCTION_NAME" 2>&1)
+    # Check if "Active" is in the response
+    if echo "$status" | grep -q "Active"; then
+        return 0
+    fi
+    return 1
+}
+
+# Wait until the Lambda function is active
+echo "Waiting for Lambda function to become active..."
+while true; do
+    if check_lambda_status; then
+        echo "Lambda function is active."
+        break
+    else
+        echo "Lambda function is still pending. Waiting..."
+        sleep 1
+    fi
+done
+
+# Invoke the Lambda function 3 times every 5 seconds.
+for i in {1..3}; do
+    echo "Invoking the Lambda function, attempt $i."
+    awslocal lambda invoke \
+        --function-name function-one \
+        test.lambda.$i.log \
+        --payload "{\"message\": \"Testing Lambda Debug Mode lifting the 1-second timeout for function-one. Attempt $i.\"}" &
+    sleep 5
+done

lambda-debug-mode/python/base-enable-lambda-debug-mode/handler.py

@@ -7,7 +7,7 @@ def handler(event, context):
     # Print the incoming invocation event.
     print(event)
 
-    # Return the incomeing invocation evant.
+    # Return the incoming invocation event.
     return event
 
 

lambda-debug-mode/python/base-multiple-lambda-debug-mode/handler_function_one.py

@@ -10,7 +10,7 @@ def handler(event, context):
     # Print the incoming invocation event.
     print(event)
 
-    # Return the incomeing invocation evant.
+    # Return the incoming invocation event.
     return event
 
 

lambda-debug-mode/python/base-multiple-lambda-debug-mode/handler_function_two.py

@@ -10,7 +10,7 @@ def handler(event, context):
     # Print the incoming invocation event.
     print(event)
 
-    # Return the incomeing invocation evant.
+    # Return the incoming invocation event.
     return event