Swagger UI served by Lambda

This example shows how to set up Swagger UI for API Gateway. It uses Lambda for serving Swagger UI.

Prerequisites

• Make sure you have AWS CLI installed and configured with an aws account you want to use.
• Ensure you have nodejs installed.

install cdk

npm install -g aws-cdk
cdk --version

create virtualenv

python3 -m venv .venv
source .venv/bin/activate

install requirements

pip install -r requirements.txt

make Lambda Layer zip file

cd layers
./install.sh
cd ..

you will get swagger.zip, this file will be used to create Lambda Layer.

setting AWS_PROFILE

export AWS_PROFILE=<the configuration profile for aws-cli>

How to deploy

First, Deploy stateful resources

cdk deploy SwaggerUI/Stateful

After deployment finished. Copy the S3 Bucket Name from the output. The output looks like below.

Outputs:
SwaggerUIStateful3F479D90.ExportsOutputFnGetAttNetworkingSwaggerUISG96F8CF33GroupIdFEF076D7 = sg-07dcde4aa56cc65eb
SwaggerUIStateful3F479D90.ExportsOutputFnGetAttS3APIDocsCB10F954ArnA7FEBE62 = arn:aws:s3:::swaggerui-stateful-s3apidocscb10f954-1q9j1u6i6ctu
SwaggerUIStateful3F479D90.ExportsOutputRefNetworkingVPCPrivateSubnet1SubnetA4560E1F1EC76AC4 = subnet-0958de613203332ff
SwaggerUIStateful3F479D90.ExportsOutputRefNetworkingVPCPrivateSubnet2Subnet388EEB72AB01EAC9 = subnet-07606fe133947524e
SwaggerUIStateful3F479D90.S3BucketName099EDA80 = swaggerui-stateful-s3apidocscb10f954-1q9j1u6i6ctu
Stack ARN:
arn:aws:cloudformation:ap-northeast-2:927208760804:stack/SwaggerUI-Stateful/bb01f180-f105-11ec-ad94-0a9de810c42a

Second, Deploy stateless resources

cdk deploy SwaggerUI/Stateless

After deployment finished. Copy the API Gateway Endpoint from the output. The output looks like below.

Outputs:
SwaggerUIStatelessAD411EB5.APIGwEndpoint2CC41FEF = https://fyp0p7n8q8.execute-api.ap-northeast-2.amazonaws.com/prod/
Stack ARN:
arn:aws:cloudformation:ap-northeast-2:927208760804:stack/SwaggerUI-Stateless/13efd670-f1c1-11ec-9bb7-0a2886132568

Then go to AWS Console.

1. In the console, go to API Gateway and select SwaggerUI.
2. In SwaggerUI, select Stages -> prod.
3. Click Export tab and download json file from Export as Swagger.

Upload json file to S3

Upload json file to S3 bucket, the bucket name is the one you copied from the deployment output.

Update environment variables of lambda function.

Execute command like below. you need to change BUCKET_NAME and KEY_NAME (json file name).

aws lambda update-function-configuration --function-name APIDocsFunc \
    --environment "Variables={BUCKET_NAME=swaggerui-stateful-s3apidocscb10f954-1q9j1u6i6ctu,KEY_NAME=SwaggerUI-prod-swagger.json}"

Load Swagger UI

Using copied API Gateway Endpoint, open Swagger UI in browser. the URL will be,

API Gateway Endpoint + /api-docs/

you can see POST and GET api description for sample API.

POST

GET