如何在无服务器框架中为多个 dynamodb 表定义 iamrolestatements 资源？答案

【问题标题】：How do I define resources for iamrolestatements for multiple dynamodb tables in serverless framework?如何在无服务器框架中为多个 dynamodb 表定义 iamrolestatements 资源？
【发布时间】：2018-03-05 18:31:20
【问题描述】：

我想在我的无服务器项目中使用多个 dynamodb 表。如何在 iamrolestatements 中正确定义多个资源？

我有一个例子serverless.yml

service: serverless-expense-tracker
frameworkVersion: ">=1.1.0 <2.0.0"

provider:
  name: aws
  runtime: nodejs6.10
  environment:
    EXPENSES_TABLE: "${self:service}-${opt:stage, self:provider.stage}-expenses"
    BUDGETS_TABLE: "${self:service}-${opt:stage, self:provider.stage}-budgets"

  iamRoleStatements:
    - Effect: Allow
      Action:
        - dynamodb:Query
        - dynamodb:Scan
        - dynamodb:GetItem
        - dynamodb:PutItem
        - dynamodb:UpdateItem
        - dynamodb:DeleteItem
      Resource: "arn:aws:dynamodb:${opt:region, self:provider.region}:*:table/${self:provider.environment.EXPENSES_TABLE}"
      # what is the best way to add the other DB as a resource

functions:
  create:
    handler: expenseTracker/create.create
    events:
      - http:
          path: expenses
          method: post
          cors: true

  list:
    handler: expenseTracker/list.list
    events:
      - http:
          path: expenses
          method: get
          cors: true

  get:
    handler: expenseTracker/get.get
    events:
      - http:
          path: expenses/{id}
          method: get
          cors: true

  update:
    handler: expenseTracker/update.update
    events:
      - http:
          path: expenses/{id}
          method: put
          cors: true

  delete:
    handler: expenseTracker/delete.delete
    events:
      - http:
          path: expenses/{id}
          method: delete
          cors: true

resources:
  Resources:
    DynamoDbExpenses:
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:provider.environment.EXPENSES_TABLE}

    DynamoDbBudgets:
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:provider.environment.BUDGETS_TABLE}

您可以在那里的 cmets 中看到相关区域。

【问题讨论】：

如果你有一个特定的问题（如何在 iam 角色声明中正确定义多个资源），然后做一个仔细的例子来展示你尝试过的东西，任何错误都不起作用，并准确解释你的意图
感谢@Vorsprung。我没有任何错误，但是让上面链接的 serverless.yml 工作的唯一方法是使用通配符定义 iam 资源。这似乎是我们工程师所说的坏主意。你能帮我以一种更加、呃、封装的方式在 iamrolestatements 中定义多个资源吗？
或者你的意思是我不应该链接到 yml 作为要点，而是直接在这里发布？
我的意思是，如果您需要某种帮助，请提出具体问题！请参阅网站指南stackoverflow.com/help/how-to-ask
已编辑，如果不够具体，请告诉我。

标签： amazon-web-services amazon-dynamodb serverless-framework

【解决方案1】：

我明白了！

关键只是在- Resource 下添加一个列表，但我还了解到，最好只使用配置表时使用的逻辑 ID。完整示例：

service: serverless-expense-tracker

frameworkVersion: ">=1.1.0 <2.0.0"

provider:
  name: aws
  runtime: nodejs6.10
  environment:
    EXPENSES_TABLE: { "Ref": "DynamoDbExpenses" } #DynamoDbExpenses is a logicalID also used when provisioning below
    BUDGETS_TABLE: { "Ref": "DynamoDbBudgets" }

  iamRoleStatements:
    - Effect: Allow
      Action:
        - dynamodb:DescribeTable
        - dynamodb:Query
        - dynamodb:Scan
        - dynamodb:GetItem
        - dynamodb:PutItem
        - dynamodb:UpdateItem
        - dynamodb:DeleteItem
      Resource:
        - { "Fn::GetAtt": ["DynamoDbExpenses", "Arn"] } #you will also see the logical IDs below where they are provisioned
        - { "Fn::GetAtt": ["DynamoDbBudgets", "Arn"] }
functions:
  create:
    handler: expenseTracker/create.create
    events:
      - http:
          path: expenses
          method: post
          cors: true

  createBudget:
    handler: expenseTracker/createBudget.createBudget
    events:
      - http:
          path: budgets
          method: post
          cors: true

  list:
    handler: expenseTracker/list.list
    events:
      - http:
          path: expenses
          method: get
          cors: true

  listBudgets:
    handler: expenseTracker/listBudgets.listBudgets
    events:
      - http:
          path: budgets
          method: get
          cors: true

  get:
    handler: expenseTracker/get.get
    events:
      - http:
          path: expenses/{id}
          method: get
          cors: true

  update:
    handler: expenseTracker/update.update
    events:
      - http:
          path: expenses/{id}
          method: put
          cors: true

  delete:
    handler: expenseTracker/delete.delete
    events:
      - http:
          path: expenses/{id}
          method: delete
          cors: true

resources:
  Resources:
    DynamoDbExpenses: #this is where the logicalID is defined
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1

    DynamoDbBudgets: #here too
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1

【讨论】：

管理两张DynamoDB表时，如何让每个函数知道需要连接哪个数据库？
在这种情况下，您会注意到我在 provider.environment 中定义了 EXPENSES_TABLE 和 BUDGETS_TABLE。在您的 lambda 中，您只需像这样引用它：TableName: process.env.EXPENSES_TABLE
但是 lambda 是在 sls 中自动创建的，我在哪里可以设置 TableName？你的意思是在更硬的脚本中？
是的，在处理程序脚本中，很抱歉造成混淆。
未在处理程序脚本中设置。我现在知道该怎么做了：serverless.com/framework/docs/providers/aws/guide/…。似乎您当前的代码将不起作用，直到您为每个函数添加环境 TABLE_NAME。

【解决方案2】：

我想发布我的更新，因为我花时间从这个问题中学到了很多东西。当前接受的答案未完全发挥作用。

我添加了什么：

1) 确保在您的处理程序中，有一个环境TABLE_NAME（或其他名称，您可以相应调整）如下，它是指 lambda 函数的环境变量

  const params = {
    TableName: process.env.TABLE_NAME,
    Item: {
      ...
    }
  }

2) 更新serverless.yml 为每个函数指定表名。

environment:
  TABLE_NAME: { "Ref": "DynamoDbExpenses" }

或

environment:
  TABLE_NAME: { "Ref": "DynamoDbBudgets" }

取决于函数的目标表。

完整的serverless.yml在这里更新：

service: serverless-expense-tracker

frameworkVersion: ">=1.1.0 <2.0.0"

provider:
  name: aws
  runtime: nodejs6.10
  environment:
    EXPENSES_TABLE: { "Ref": "DynamoDbExpenses" } #DynamoDbExpenses is a logicalID also used when provisioning below
    BUDGETS_TABLE: { "Ref": "DynamoDbBudgets" }

  iamRoleStatements:
    - Effect: Allow
      Action:
        - dynamodb:DescribeTable
        - dynamodb:Query
        - dynamodb:Scan
        - dynamodb:GetItem
        - dynamodb:PutItem
        - dynamodb:UpdateItem
        - dynamodb:DeleteItem
      Resource:
        - { "Fn::GetAtt": ["DynamoDbExpenses", "Arn"] } #you will also see the logical IDs below where they are provisioned
        - { "Fn::GetAtt": ["DynamoDbBudgets", "Arn"] }
functions:
  create:
    handler: expenseTracker/create.create
    environment:
      TABLE_NAME: { "Ref": "DynamoDbExpenses" }
    events:
      - http:
          path: expenses
          method: post
          cors: true

  createBudget:
    handler: expenseTracker/createBudget.createBudget
    environment:
      TABLE_NAME: { "Ref": "DynamoDbBudgets" }
    events:
      - http:
          path: budgets
          method: post
          cors: true

  list:
    handler: expenseTracker/list.list
    environment:
      TABLE_NAME: { "Ref": "DynamoDbExpenses" }
    events:
      - http:
          path: expenses
          method: get
          cors: true

  listBudgets:
    handler: expenseTracker/listBudgets.listBudgets
    environment:
      TABLE_NAME: { "Ref": "DynamoDbBudgets" }
    events:
      - http:
          path: budgets
          method: get
          cors: true

  get:
    handler: expenseTracker/get.get
    environment:
      TABLE_NAME: { "Ref": "DynamoDbExpenses" }
    events:
      - http:
          path: expenses/{id}
          method: get
          cors: true

  update:
    handler: expenseTracker/update.update
    environment:
      TABLE_NAME: { "Ref": "DynamoDbExpenses" }
    events:
      - http:
          path: expenses/{id}
          method: put
          cors: true

  delete:
    handler: expenseTracker/delete.delete
    environment:
      TABLE_NAME: { "Ref": "DynamoDbExpenses" }
    events:
      - http:
          path: expenses/{id}
          method: delete
          cors: true

resources:
  Resources:
    DynamoDbExpenses: #this is where the logicalID is defined
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:service}-${opt:stage, self:provider.stage}-expenses

    DynamoDbBudgets: #here too
      Type: 'AWS::DynamoDB::Table'
      DeletionPolicy: Retain
      Properties:
        AttributeDefinitions:
          -
            AttributeName: id
            AttributeType: S
        KeySchema:
          -
            AttributeName: id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        TableName: ${self:service}-${opt:stage, self:provider.stage}-budgets

参考：

serverless environment variables

【讨论】：

【解决方案3】：

如果您的意图是提供对正在部署的堆栈中所有表的访问，您可以使用：

Resource: !Sub arn:aws:dynamodb:${AWS::Region}:${AWS::AccountId}:table/${AWS::StackName}-*

这样，您的堆栈中的 lambdas 仅限于堆栈中的表，您不必在每次添加表时都更新它。

【讨论】：