Add Lambda debug mode, hot reload, and rename website bucket to 'app'

- Add .localstack/lambda_debug_mode.yaml for order-handler debug on port 19891
- Add debug-start and hot-reload Makefile targets
- Update .vscode/launch.json to debugpy remote attach config
- Add .vscode/extensions.json with recommended extensions
- Add ms-python.python to devcontainer extensions
- Rename S3 website bucket from orders-ui to app

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: whummer

.devcontainer/devcontainer.json

@@ -10,7 +10,8 @@
       "extensions": [
         "amazonwebservices.aws-toolkit-vscode",
         "localstack.localstack",
-        "hashicorp.terraform"
+        "hashicorp.terraform",
+        "ms-python.python"
       ]
     },
     "codespaces": {

.localstack/lambda_debug_mode.yaml

@@ -0,0 +1,4 @@
+functions:
+  order-handler:
+    debug-port: 19891
+    enforce-timeouts: false

.vscode/extensions.json

@@ -0,0 +1,8 @@
+{
+  "recommendations": [
+    "amazonwebservices.aws-toolkit-vscode",
+    "localstack.localstack",
+    "hashicorp.terraform",
+    "ms-python.python"
+  ]
+}

.vscode/launch.json

@@ -2,30 +2,19 @@
   "version": "0.2.0",
   "configurations": [
     {
-      "name": "Debug order-handler (LocalStack)",
-      "type": "aws-sam",
-      "request": "direct-invoke",
-      "invokeTarget": {
-        "target": "code",
-        "lambdaHandler": "handler.handler",
-        "projectRoot": "${workspaceFolder}/01-serverless-app/lambdas/order_handler"
+      "name": "Attach to order-handler (LocalStack debug mode)",
+      "type": "debugpy",
+      "request": "attach",
+      "connect": {
+        "host": "localhost",
+        "port": 19891
       },
-      "lambda": {
-        "runtime": "python3.12",
-        "payload": {
-          "json": {
-            "body": "{\"item\": \"debug-test\", \"quantity\": 1}"
-          }
-        },
-        "environmentVariables": {
-          "ORDERS_TABLE": "orders",
-          "ORDERS_QUEUE_URL": "http://localhost:4566/000000000000/orders-queue",
-          "AWS_ENDPOINT_URL": "http://localhost:4566"
+      "pathMappings": [
+        {
+          "localRoot": "${workspaceFolder}/01-serverless-app/lambdas/order_handler",
+          "remoteRoot": "/var/task"
         }
-      },
-      "sam": {
-        "localArguments": ["--debug-port", "5890"]
-      }
+      ]
     }
   ]
 }

01-serverless-app/README.md

@@ -93,7 +93,7 @@ awslocal s3 ls s3://order-receipts/
 
 ```bash
 echo "Website: $(tflocal output -raw website_url)"
-# Open http://localhost:4566/orders-ui/index.html in your browser
+# Open http://localhost:4566/app/index.html in your browser
 ```
 
 ---

01-serverless-app/terraform/main.tf

@@ -591,7 +591,7 @@ locals {
 }
 
 resource "aws_s3_bucket" "website" {
-  bucket = "orders-ui"
+  bucket = "app"
 }
 
 resource "aws_s3_bucket_public_access_block" "website" {
@@ -634,5 +634,5 @@ output "api_endpoint" {
 }
 
 output "website_url" {
-  value = "http://localhost:4566/orders-ui/index.html"
+  value = "http://localhost:4566/app/index.html"
 }

Makefile

@@ -12,6 +12,21 @@ help: ## Show this help
 start: ## Start LocalStack in the background
 	LOCALSTACK_APPINSPECTOR_ENABLE=1 LOCALSTACK_APPINSPECTOR_DEV_ENABLE=1 localstack start -d
 
+debug-start: ## Start LocalStack with Lambda debug mode enabled (port 19891)
+	LOCALSTACK_APPINSPECTOR_ENABLE=1 LOCALSTACK_APPINSPECTOR_DEV_ENABLE=1 \
+	  LAMBDA_DOCKER_FLAGS='-p 19891:19891' \
+	  LAMBDA_DEBUG_MODE_CONFIG_PATH=$(PWD)/.localstack/lambda_debug_mode.yaml \
+	  localstack start -d
+
+hot-reload: ## Switch order-handler to hot-reload mode (edits take effect immediately)
+	awslocal lambda update-function-code \
+	  --function-name order-handler \
+	  --s3-bucket hot-reload \
+	  --s3-key $(PWD)/01-serverless-app/lambdas/order_handler
+
+hot-reload-off: ## Restore order-handler to the packaged ZIP (disable hot reload)
+	cd $(TERRAFORM_DIR) && tflocal apply -auto-approve -target=aws_lambda_function.order_handler
+
 stop: ## Stop LocalStack
 	localstack stop
 
@@ -111,6 +126,7 @@ iam-status: ## Show current IAM enforcement state and Lambda role policies
 publish-token: ## Upload LOCALSTACK_AUTH_TOKEN to S3 for workshop participants
 	bash scripts/publish-workshop-token.sh
 
-.PHONY: help start stop status logs setup init build deploy destroy redeploy outputs \
+.PHONY: help start stop status logs setup debug-start hot-reload hot-reload-off \
+        init build deploy destroy redeploy outputs \
         test test-fast open-ui api-endpoint inject-fault remove-fault replay-dlq \
         iam-enforce iam-off iam-fix iam-status publish-token

README.md

@@ -120,5 +120,8 @@ make replay-dlq     # Replay messages from the DLQ
 make iam-enforce    # Enable IAM policy enforcement
 make iam-fix        # Grant missing dynamodb:PutItem to the Lambda role
 make iam-off        # Disable IAM enforcement (permissive mode)
+make debug-start    # Start LocalStack with Lambda debug mode (port 19891)
+make hot-reload     # Switch order-handler to hot-reload mode
+make hot-reload-off # Restore order-handler to packaged ZIP
 make logs           # Tail LocalStack logs
 ```