There are two ways to achieve this:
Method 1: By defining the "Lambda", "API Gateway", "API Resource" and "API Methods". Linking the Lambda using the URI statement under "API Method".
MyLambdaFunction:
Type: "AWS::Lambda::Function"
Properties:
Description: "Node.js Express REST API"
FunctionName: "get_list_function" (The name in AWS console)
Handler: lambda.handler
Runtime: nodejs12
MemorySize: 128
Role: <ROLE ARN>
Timeout: 60
apiGateway:
Type: "AWS::ApiGateway::RestApi"
Properties:
Name: "example-api-gw"
Description: "Example API"
ProxyResource:
Type: "AWS::ApiGateway::Resource"
Properties:
ParentId: !GetAtt apiGateway.RootResourceId
RestApiId: !Ref apiGateway
PathPart: '{proxy+}' OR "a simple string like "PetStore"
apiGatewayRootMethod:
Type: "AWS::ApiGateway::Method"
Properties:
AuthorizationType: NONE
HttpMethod: ANY
Integration:
IntegrationHttpMethod: POST
Type: AWS_PROXY
IntegrationResponses:
- StatusCode: 200
Uri: !Sub >-
arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${MyLambdaFunction.Arn}/invocations
ResourceId: !Ref ProxyResource
RestApiId: !Ref "apiGateway"
METHOD 2: Define "API Gateway" and "Lambda". In Lambda definitions, call Events of type API.
CoreApi:
Type: 'AWS::Serverless::Api'
Properties:
StageName: dev
Name: SaaSAPI
EndpointConfiguration: Regional
Cors:
AllowMethods: '''POST, GET, OPTIONS, PATCH, DELETE, PUT'''
AllowHeaders: '''Content-Type, X-Amz-Date, Authorization, X-Api-Key, x-requested-with'''
AllowOrigin: '''*'''
MaxAge: '''600'''
MyLambdaFunction:
Type: "AWS::Lambda::Function"
Properties:
Description: "Node.js Express REST API"
FunctionName: "get_list_function"
Handler: lambda.handler
Runtime: nodejs12
MemorySize: 128
Role: <ROLE ARN>
Timeout: 60
Events:
ProxyResourceA:
Type: Api
Properties:
Path: /Departments
Method: GET
RestApiId: !Ref CoreApi
ProxyResourceB:
Type: Api
Properties:
Path: /Departments (This becomes the resource in API Gateway)
Method: POST
RestApiId: !Ref CoreApi
(You can link multiple methods with the same lambda, provide a unique name to each event, like ProxyResoruceA & ProxyResourceB)