feat: lambda emulator and test directory

Author: shawnhankim

.gitignore

@@ -8,6 +8,8 @@
 *.crt
 *.key
 settings.test
+__pycache__/*
+*.pyc
 
 # User-specific stuff
 .idea/**/workspace.xml

docs/img/lambda_emulator.png

@@ -0,0 +1,13 @@
+FROM public.ecr.aws/lambda/python:3.8
+
+# Install the function's dependencies using file requirements.txt
+# from your project folder.
+
+COPY requirements.txt  .
+RUN  pip3 install -r requirements.txt --target "${LAMBDA_TASK_ROOT}"
+
+# Copy function code
+COPY app/lambda_function.py ${LAMBDA_TASK_ROOT}
+
+# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
+CMD [ "lambda_function.lambda_handler" ] 

tests/integration/.gitkeep

@@ -0,0 +1,16 @@
+start:
+	docker-compose up -d
+
+ps:
+	docker ps --format "table {{.ID}}\t{{.Image}}\t{{.Ports}}\t{{.Names}}"
+
+watch:
+	watch 'docker ps --format "table {{.ID}}\t{{.Image}}\t{{.Ports}}\t{{.Names}}"'
+
+down:
+	docker-compose down
+
+clean: 
+	docker kill $$(docker ps -q) 2> /dev/null || true
+	docker system prune -a
+	docker volume rm $(docker volume ls -qf dangling=true)

tests/lambda-emulator/Dockerfile

@@ -0,0 +1,57 @@
+# AWS Lambda Runtime Interface Emulator
+
+The AWS Lambda Runtime Interface Emulator (RIE) is a proxy for the Lambda Runtime API that allows you to locally test your Lambda function packaged as a container image. The emulator is a lightweight web server that converts HTTP requests into JSON events to pass to the Lambda function in the container image.
+
+> Note: The RIE does not emulate **Lambda’s security and authentication configurations**, or Lambda orchestration.
+
+
+## Getting Started
+
+- **Implement a Lambda Function:**
+  
+  e.g., [`app/lambda_function.py`](./app/lambda_function.py):
+
+  ```python
+    import json
+
+    def lambda_handler(event, context):
+        return {
+            'statusCode': 200,
+            'body': {
+                'request': event,
+                'response': 'Hello from NGINX Lambda Gateway Emulator!'
+            }
+        }
+  ```
+
+- **Start a Lambda Emulator:**
+  ```bash
+  make start
+  ```
+
+- **Check if Lambda Emulator is started:**
+  ```bash
+  make watch
+  ```
+  ![](../../docs/img/lambda_emulator.png)
+
+- **Test a function via Lambda Emulator:**
+  ```bash
+  curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"message": "This is to test a Lambda Function ARN."}'
+
+  curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
+  ```
+
+- **Stop a Lambda Emulator:**
+  ```bash
+  make down
+  ```
+
+- **Clean Lambda Emulator Container Image:**
+  ```bash
+  make clean
+  ```
+
+## References
+- [Testing Lambda container images locally](https://docs.aws.amazon.com/lambda/latest/dg/images-test.html)
+- [Using AWS Lambda environment variables](https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html)

tests/lambda-emulator/Makefile

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+import json
+
+def lambda_handler(event, context):
+    return {
+        'statusCode': 200,
+        'body': {
+            'request': event,
+            'response': 'Hello from NGINX Lambda Gateway Emulator - /foo!'
+        }
+    }

tests/lambda-emulator/README.md

@@ -0,0 +1,23 @@
+version: '3'
+services:
+
+  lambda_emulator:
+    hostname: lambda_emulator
+    container_name: lambda_emulator
+    image: lambda_emulator
+    build:
+      context: ./
+      dockerfile: Dockerfile
+    env_file:
+      - settings.env
+    volumes:
+      - type: bind
+        source: ./app
+        target: /var/task/
+    ports:
+      - "9000:8080"
+    networks:
+      - mynetwork
+
+networks:
+  mynetwork:

tests/lambda-emulator/app/lambda_function.py

@@ -0,0 +1,5 @@
+AWS_ACCESS_KEY_ID=aaaaa
+AWS_SECRET_ACCESS_KEY=bbbbb
+AWS_SESSION_TOKEN=ccccc
+AWS_REGION=us-east-2
+AWS_LAMBDA_FUNCTION_NAME=foo