Trouble Shooting Tips

General testing

https://www.npmjs.com/package/aws-sdk-mock

API Gateway

Trouble shooting methods

Test:

First start from Test in resource. Will find:

• Http request method, headers, body before transformation etc.
• Endpoint of back-end service
• Endpoint request headers, body after transformation
• Call result before / after transformation

CloudWatch:

• https://aws.amazon.com/premiumsupport/knowledge-center/api-gateway-cloudwatch-logs/
• First create a role that has the principle "apigateway.amazonaws.com" and has privilege to log to cloud watch
• In API Gateway setting (the service, not the specific API), provide that role to API Gateway
• In the specific API's stage, enable logging
• Most complete

Common errors & symptom

• Without authorization to call back-end service: 500, "API Configuration Error" (if response is set), "Execution failed due to configuration error: Invalid permissions on Lambda function" in Test logs. Check Lambda side, there is no event configured. No authorization. In SAM template, the 'AWS::Serverless::Function' resource should have "Events" provided even the API side's swagger document has integration.