A demo project to test the AWS Lambda container support with Python FastAPI framework. The purpose of the project is to show how to develop a REST API with FastAPI, how to build & test it locally and how to deploy it on AWS using serverless services (AWS ECR, AWS Lambda & AWS API Gateway).
- Docker CLI
- Python 3.8
A requirements file declare all dependencies (Mangum, FastAPI, Uvicorn, ...). Use the following command to install the required dependencies (For Python 3.8.5)
pip install -r ./requirements.txt
TIP : Before installing required dependencies, do not forget to create a virtual environment using your favorite tool (Conda, ...).
You can either use the following command :
python -m app.app
Or deploy on uvicorn :
uvicorn app.app:app --reload --host 0.0.0.0 --port 5000
You can test the application by using the following command :
curl http://localhost:5000/hello/
This command builds a container which will run a Uvicorn server and deploy the ASGI app on it :
docker build -t hello-world-uvicorn .
The command starts the container :
docker run -p 5000:5000 hello-world-uvicorn:latest
You can make a test with this command :
curl http://localhost:5000/hello/
Now we can build the container for AWS Lambda which will use the Mangum handler. We use another Dockerfile which will use a base image provided by AWS :
docker build -t hello-world-lambda . -f Dockerfile.aws.lambda
Let's start the container to test the lambda locally :
docker run -p 9000:8080 hello-world-lambda:latest
We send the input event that the lambda would receive from the API Gateway with the following command :
curl -XPOST "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{
"resource": "/hello",
"path": "/hello/",
"httpMethod": "GET",
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"cache-control": "no-cache",
"CloudFront-Forwarded-Proto": "https",
"CloudFront-Is-Desktop-Viewer": "true",
"CloudFront-Is-Mobile-Viewer": "false",
"CloudFront-Is-SmartTV-Viewer": "false",
"CloudFront-Is-Tablet-Viewer": "false",
"CloudFront-Viewer-Country": "US",
"Content-Type": "application/json",
"headerName": "headerValue",
"Host": "gy415nuibc.execute-api.us-east-1.amazonaws.com",
"Postman-Token": "9f583ef0-ed83-4a38-aef3-eb9ce3f7a57f",
"User-Agent": "PostmanRuntime/2.4.5",
"Via": "1.1 d98420743a69852491bbdea73f7680bd.cloudfront.net (CloudFront)",
"X-Amz-Cf-Id": "pn-PWIJc6thYnZm5P0NMgOUglL1DYtl0gdeJky8tqsg8iS_sgsKD1A==",
"X-Forwarded-For": "54.240.196.186, 54.182.214.83",
"X-Forwarded-Port": "443",
"X-Forwarded-Proto": "https"
},
"multiValueHeaders":{
"Accept":[
"*/*"
],
"Accept-Encoding":[
"gzip, deflate"
],
"cache-control":[
"no-cache"
],
"CloudFront-Forwarded-Proto":[
"https"
],
"CloudFront-Is-Desktop-Viewer":[
"true"
],
"CloudFront-Is-Mobile-Viewer":[
"false"
],
"CloudFront-Is-SmartTV-Viewer":[
"false"
],
"CloudFront-Is-Tablet-Viewer":[
"false"
],
"CloudFront-Viewer-Country":[
"US"
],
"":[
""
],
"Content-Type":[
"application/json"
],
"headerName":[
"headerValue"
],
"Host":[
"gy415nuibc.execute-api.us-east-1.amazonaws.com"
],
"Postman-Token":[
"9f583ef0-ed83-4a38-aef3-eb9ce3f7a57f"
],
"User-Agent":[
"PostmanRuntime/2.4.5"
],
"Via":[
"1.1 d98420743a69852491bbdea73f7680bd.cloudfront.net (CloudFront)"
],
"X-Amz-Cf-Id":[
"pn-PWIJc6thYnZm5P0NMgOUglL1DYtl0gdeJky8tqsg8iS_sgsKD1A=="
],
"X-Forwarded-For":[
"54.240.196.186, 54.182.214.83"
],
"X-Forwarded-Port":[
"443"
],
"X-Forwarded-Proto":[
"https"
]
},
"queryStringParameters": {
},
"multiValueQueryStringParameters":{
},
"pathParameters": {
},
"stageVariables": {
"stageVariableName": "stageVariableValue"
},
"requestContext": {
"accountId": "12345678912",
"resourceId": "roq9wj",
"stage": "testStage",
"requestId": "deef4878-7910-11e6-8f14-25afc3e9ae33",
"identity": {
"cognitoIdentityPoolId": null,
"accountId": null,
"cognitoIdentityId": null,
"caller": null,
"apiKey": null,
"sourceIp": "192.168.196.186",
"cognitoAuthenticationType": null,
"cognitoAuthenticationProvider": null,
"userArn": null,
"userAgent": "PostmanRuntime/2.4.5",
"user": null
},
"resourcePath": "/hello/",
"httpMethod": "GET",
"apiId": "gy415nuibc"
},
"body": "{}",
"isBase64Encoded": false
}'
See the server logs :
(fastapi-lambda-container) gbdevw@gbdevw-dev:~/python-fastapi-aws-lambda-container$ docker run -p 9000:8080 hello-world:latest
time="2020-12-28T15:31:13.892" level=info msg="exec '/var/runtime/bootstrap' (cwd=/var/task, handler=)"
time="2020-12-28T15:31:18.345" level=info msg="extensionsDisabledByLayer(/opt/disable-extensions-jwigqn8j) -> stat /opt/disable-extensions-jwigqn8j: no such file or directory"
time="2020-12-28T15:31:18.345" level=warning msg="Cannot list external agents" error="open /opt/extensions: no such file or directory"
START RequestId: b7cd3c8d-6c70-4194-b5bd-6a0b8e766b1f Version: $LATEST
{"timestamp": "2020-12-28T15:31:18.650259", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "Waiting for application startup."}
{"timestamp": "2020-12-28T15:31:18.650726", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "LifespanCycleState.STARTUP: 'lifespan.startup.complete' event received from application."}
{"timestamp": "2020-12-28T15:31:18.650863", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "Application startup complete."}
{"timestamp": "2020-12-28T15:31:18.651481", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "api-request", "message": "Request", "uuid": "bd8ec07d-2b70-436d-8157-1d802be13240", "method": "GET", "url": "https://gy415nuibc.execute-api.us-east-1.amazonaws.com/hello/"}
{"timestamp": "2020-12-28T15:31:18.652105", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "api-response", "message": "Response sent", "uuid": "bd8ec07d-2b70-436d-8157-1d802be13240", "code": 200}
{"timestamp": "2020-12-28T15:31:18.652506", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "HTTPCycleState.REQUEST: 'http.response.start' event received from application."}
{"timestamp": "2020-12-28T15:31:18.652641", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "HTTPCycleState.RESPONSE: 'http.response.body' event received from application."}
{"timestamp": "2020-12-28T15:31:18.652750", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "HTTPCycleState.RESPONSE: 'http.response.body' event received from application."}
{"timestamp": "2020-12-28T15:31:18.652996", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "HTTPCycleState.RESPONSE: 'http.response.body' event received from application."}
{"timestamp": "2020-12-28T15:31:18.653305", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "Waiting for application shutdown."}
{"timestamp": "2020-12-28T15:31:18.653449", "level": "INFO", "service": "Helloworld", "instance": "84cc35a9-965e-4ac9-9f45-6554341c0dc2", "type": "internal", "message": "LifespanCycleState.SHUTDOWN: 'lifespan.shutdown.complete' event received from application."}
END RequestId: b7cd3c8d-6c70-4194-b5bd-6a0b8e766b1f
REPORT RequestId: b7cd3c8d-6c70-4194-b5bd-6a0b8e766b1f Init Duration: 0.42 ms Duration: 308.38 ms Billed Duration: 400 ms Memory Size: 3008 MB Max Memory Used: 3008 MB
And the lambda output :
{"isBase64Encoded": false, "statusCode": 200, "headers": {"content-length": "25", "content-type": "application/json", "x-correlation-id": "e6ccda71-c841-40de-8208-aff40a2b155b"}, "body": "{\"message\":\"Hello World\"}"}Step by step guide to deploy the application on AWS using console