Serverless で複数の AWS アカウントを使用する

# ~/.aws/credentials
[foo-dev]
aws_access_key_id = AKIAAAAAAAAAAAAAAAAA
aws_secret_access_key = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

[foo-pro]
aws_access_key_id = AKIBBBBBBBBBBBBBBBBB
aws_secret_access_key = yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

custom:
  awsAccountId:
    dev: 111111111111
    pro: 222222222222
  region:
    dev: us-east-1
    pro: ap-northeast-1
  deploymentBucket:
    dev: foo-deployment-dev
    pro: foo-deployment-pro
  dataBucket:
    dev: foo-dev
    pro: foo-pro

provider:
  name: aws
  runtime: python3.6

  stage: ${opt:stage, 'dev'}
  region: ${self:custom.region.${self:provider.stage}}
  # role iamRoleStatements で定義することも出来ますが、
  # 事前に作っておき、以下の行のように指定した方が管理が楽です。
  role: arn:aws:iam::${self:custom.awsAccountId.${self:provider.stage}}:role/Lambda_exec_role
  deploymentBucket:
    name: ${self:custom.deploymentBucket.${self:provider.stage}} # Deployment bucket name. Default is generated by the framework
    serverSideEncryption: AES256 # when using server-side encryption

functions:
  bar_func:
    handler: bar_func.${self:provider.stage}_handler_bar_func
    name: ${self:provider.stage}_bar_func
    # 以下省略

sls deploy --stage pro # 本番環境へデプロイ
sls deploy --stage dev # 開発環境へデプロイ