serverless/lib/plugins/aws/custom-resources/resources/s3/handler.js

'use strict'

const { addPermission, removePermission } = require('./lib/permissions')
const { updateConfiguration, removeConfiguration } = require('./lib/bucket')
const { getEnvironment, getLambdaArn, handlerWrapper } = require('../utils')

async function handler(event, context) {
  if (event.RequestType === 'Create') {
    return create(event, context)
  } else if (event.RequestType === 'Update') {
    return update(event, context)
  } else if (event.RequestType === 'Delete') {
    return remove(event, context)
  }
  throw new Error(`Unhandled RequestType ${event.RequestType}`)
}

async function create(event, context) {
  const { Partition, Region, AccountId } = getEnvironment(context)
  const { FunctionName, BucketName, BucketConfigs } = event.ResourceProperties

  const lambdaArn = getLambdaArn(Partition, Region, AccountId, FunctionName)

  return addPermission({
    functionName: FunctionName,
    bucketName: BucketName,
    partition: Partition,
    region: Region,
    accountId: AccountId,
  }).then(() =>
    updateConfiguration({
      lambdaArn,
      region: Region,
      functionName: FunctionName,
      bucketName: BucketName,
      bucketConfigs: BucketConfigs,
    }),
  )
}

async function update(event, context) {
  const { Partition, Region, AccountId } = getEnvironment(context)
  const { FunctionName, BucketName, BucketConfigs } = event.ResourceProperties

  const lambdaArn = getLambdaArn(Partition, Region, AccountId, FunctionName)

  return updateConfiguration({
    lambdaArn,
    region: Region,
    functionName: FunctionName,
    bucketName: BucketName,
    bucketConfigs: BucketConfigs,
  })
}

async function remove(event, context) {
  const { Region } = getEnvironment(context)
  const { FunctionName, BucketName } = event.ResourceProperties

  return removePermission({
    functionName: FunctionName,
    bucketName: BucketName,
    region: Region,
  }).then(() =>
    removeConfiguration({
      region: Region,
      functionName: FunctionName,
      bucketName: BucketName,
    }),
  )
}

module.exports = {
  handler: handlerWrapper(handler, 'CustomResourceExistingS3'),
}