use the stage variable in serverless.yml at handler.js

Question

I'd like to use the variable stage in handler.js

serverless.yml

provider:
  name: aws
  runtime: nodejs10.x
  region: ap-northeast-2
  stage: ${opt:stage, "dev"}
...

handler.js

export const hello = () => {
  // I'd like to use the stage in here,
  const isDev = stage === 'dev';
  return {
    statusCode: 200,
    body: {
      message: `isDev ${isDev}`
    }
  }
}

Answer 1

If your method of integration is "Lambda Proxy Integration", You should be able to access stage via event.requestContext.stage.

export const hello = (event) => {
  // I'd like to use the stage in here,
  console.log('stage is: ', event.context.stage)
  const isDev = stage === 'dev';
  return {
    statusCode: 200,
    body: {
      message: `isDev ${isDev}`
    }
  }
}