Integrate an API with lambda

An API gateway end point can be have multiple integration types. To integrate an API with lambda as backend there are two ways. One is lambda integration and the other is lambda proxy integration. With lambda integration as the type of set up, AWS provides an ability to perform body mapping template. Below is the screenshot depicting a resource with GET method having lambda integration.


Once the resource creation is complete we should see the below screen

There are several options and configurations possible. Let us list each one of them and go through them in detail
1. Ability to quickly do a test of the end point (resource with method)
2. Method Request
3. Integration Request
4. Integration Response
5. Method Response
6. Link to Lambda function associated with the endpoint (hello in above example)

When we enable the checkbox and choose lambda proxy as the integration type then the section Integration Response become disabled.  Let us dive in to the details of each of the above mentioned parts

 1. Test button


This button takes us to a screen which provides an easy way to quickly test the api being developed.
On providing the necessary values and running the test we should be able to see the lambda invoked and the results along with log details related to the request



If the method that is being invoked requires header values or query parameters we can provide them in the text box. In our scenario we did not have any such requirement and hence they were empty.


Comments

Post a Comment

Popular posts from this blog

Integrate an API with lambda - Part 5

Image
In this part of the blog we will cover the section Integration Response  in detail. This is where we configuration how the response needs to be mapped. On clicking the  details we get a similar screen In here we could add multiple integration responses. This is a very important section for output error code mapping.  If we intend to capture some keyword coming from backend we can use regex expression to filter response and handle the conversion. For example, we could expression .*exception*. to filter responses which has exception occurring any where and map it to error code like 500. Below screenshots shows the steps involved in achieving this.
Read more

Custom authorizer

Creating custom authorizer using SAM AWSTemplateFormatVersion: '2010-09-09' Transform: AWS::Serverless-2016-10-31 Resources:   Api:     Type: AWS::Serverless::Api     Properties:       StageName: devtesting       DefinitionBody:         swagger: "2.0"         info:           title:             Ref: AWS::StackName         description: My API that uses custom authorizer         version: 1.0.0         paths:           "/getmesomething":             get:               x-amazon-apigateway-integration:                 httpMethod: GET                 type: aws_proxy         ...
Read more

Dynamically clean up lambda

Below snippet shows how to clean up a lambda resource and its associated ENI --- Resources:   LambdaFunction:     Type: "AWS::Lambda::Function"     Properties:       Handler: "index.lambda_handler"       Role: !GetAtt LambdaFunctionRole.Arn       Code:         ZipFile: !Sub |           def lambda_handler(event, context):             print('Hello World')       Runtime: "python2.7"       Timeout: "60"       VpcConfig:         SecurityGroupIds:           - !Ref SecurityGroup1           - !Ref SecurityGroup2         SubnetIds:           - !Ref Subnet1           - !Ref Subnet2   VPCLambdaCleanupCustomResource:     Type: Custom::...
Read more