Lambda Integration vs. Lambda Proxy: Pros and Cons

Question

What do you think are the Pros and Cons of using Lambda integration with and without the proxy feature in AWS API Gateway (and more specifically, when using the Serverless f

Answer 1

Because of body mapping template - proxy is better.

I do not like body mapping template because in exported Swagger it is escaped, for example:

        uri: "arn:aws:apigateway:us-east-1:dynamodb:action/UpdateItem"
        responses:
          default:
            statusCode: "200"
        requestTemplates:
          application/json: "{\n    \"TableName\": \"happy-marketer\",\n    \"Key\"\
            : {\n        \"pk\": {\n            \"S\": \"project\"\n        },\n \
            \       \"sk\": {\n            \"S\": \"$context.authorizer.claims.email\
            \ $util.urlDecode($input.params('name'))\"\n        }\n    },\n    \"\
            UpdateExpression\": \"SET projectStatus = :c\",\n    \"ExpressionAttributeValues\"\
            : {\n        \":c\": {\n            \"S\": \"Completed\"\n\n        }\n\
            \    }\n}"
        passthroughBehavior: "never"
        httpMethod: "POST"
        type: "aws"
  /projects/{name}/status/restore:
    options:
      consumes:
      - "application/json"
      produces:
      - "application/json"
      parameters:
      - name: "name"
        in: "path"

And as you understand - this is bad to edit such "code" locally and deploy this swagger file. Also when you edit body mapping template in the browser - you will not receive errors about your wrong JSON / Apache Velocity. For example here we have a mistake:

{
  "email": "$context.authorizer.claims.email",
  "nameOld": "$util.urlDecode($input.params('name'))",

  #if ($input.path('$.nameNew') != "")
  "nameNew": "$util.urlDecode($input.path('$.nameNew'))",
  #end

  #if ($input.path('$.ownerNew') != "")
  "ownerNew": "$input.path('$.ownerNew')",
  #end

  #if ($input.path('$.shared') != "")
  "shared": $input.json('$.shared')
  #end

  #if ($input.path('$.StartDate') != "")
  , "startDate": "$input.path('$.StartDate')"
  #end

  #if ($input.path('$.DueDate') != "")
  , "dueDate": "$input.path('$.DueDate')"
  #end
}

The mistake is - wrong , before startDate. My backend code in Go is free from such mistakes. I do not want to write tests for Apache Velocity.

Also, maybe Proxy Integrations are faster - because of missing "service-in-the-middle".