AWS Lambda（五）---用cloudformation部署lambda函数

任务描述：

（1）在S3上面新建两个bucket，一个bucket A是存放lambda代码压缩文件的地方，一个bucketB当做收货的地方；

（2）cloudformation中写yaml脚本创建template，yaml脚本中实现的功能有：把lambda代码压缩包从bucket A取出来，创建lambda函数并启动，在s3新建一个指定名字的bucket。接着利用此template继续新建一个stack。

（3）步骤（2）完毕后，可以在s3中看到一个带有source字眼的bucket生成了，在这个bucket中上传一张.jpg图片，跑起来的lambda函数从此bucket中取到图片，并把大小改了，再存入bucket B。

1. 在s3页面，创建两个bucket，一个作为source，一个作为destination。选择一个bucket，上传lambda的zip文件(下载地址为https://download.csdn.net/download/daiqinge/12006492)。

我自己的情况，两个bucket的那么分别是：cfst-694-d88cad3582794cda5c0a9f2b857647df-bucketa-skln4rf5zz8g

和cfst-694-d88cad3582794cda5c0a9f2b857647df-bucketb-i65demszsd95

2. 创建一个cloudformation

cloudformation页面，点击新建stack：

下图中的template区域的代码如下，里面配置了只监控上传bucket中的图片后缀为.jpg的文件，才会触发调用lambda函数：

AWSTemplateFormatVersion: '2010-09-09'
Description: CloudFormation Template for Student Use
Resources:
  LambdaRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - sts:AssumeRole
      Path: /
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              - Effect: Allow
                Action:
                  - cloudwatch:DeleteAlarms
                  - cloudwatch:DescribeAlarmHistory
                  - cloudwatch:DescribeAlarms
                  - cloudwatch:DescribeAlarmsForMetric
                  - cloudwatch:GetMetricStatistics
                  - cloudwatch:ListMetrics
                  - cloudwatch:PutMetricAlarm
                  - logs:CreateLogGroup
                  - logs:CreateLogStream
                  - logs:PutLogEvents
                  - iam:GetRole
                  - iam:ListRoles
                  - lambda:*
                  - s3:GetBucketPolicy
                  - s3:GetObject
                  - s3:HeadBucket
                  - s3:ListAllMyBuckets
                  - s3:ListBucket
                  - s3:ListObjects
                  - s3:PutBucketNotification
                  - s3:GetBucketNotification
                  - s3:PutObject
                  - s3:PutObjectTagging
                Resource: '*'
      RoleName: lambda_exec_role
  SourceBucket:
    Type: AWS::S3::Bucket
    DependsOn: S3InvokeRole
    Properties:
      Tags:
        -
          Key: "Bucket"
          Value: "TriggerBucket"
      NotificationConfiguration:
        LambdaConfigurations:
          -
            Event: "s3:ObjectCreated:*"
            Function: !GetAtt LambdaFunction.Arn
            Filter:
              S3Key:
                Rules:
                  -
                    Name: suffix
                    Value: .jpg
      
  S3InvokeRole:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt 'LambdaFunction.Arn'
      Principal: s3.amazonaws.com
  LambdaRolePolicy:
    DependsOn:
      - LambdaRole
    Type: AWS::IAM::Policy
    Properties:
      PolicyName: LambdaRolePolicy
      Roles:
        - !Ref 'LambdaRole'
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Action:
              - cloudwatch:DeleteAlarms
              - cloudwatch:DescribeAlarmHistory
              - cloudwatch:DescribeAlarms
              - cloudwatch:DescribeAlarmsForMetric
              - cloudwatch:GetMetricStatistics
              - cloudwatch:ListMetrics
              - cloudwatch:PutMetricAlarm
              - logs:CreateLogGroup
              - logs:CreateLogStream
              - logs:PutLogEvents
              - iam:GetRole
              - iam:ListRoles
              - lambda:*
            Resource: '*'
  LambdaFunction:
    Type: AWS::Lambda::Function
    DependsOn:
      - LambdaRole
      - LambdaRolePolicy
    Properties:
      Code:
        S3Bucket: !Ref 'CodeBucket'
        S3Key: !Ref 'LambdaFileName'
      Role: !GetAtt 'LambdaRole.Arn'
      Description: This function creates a thumbnail version of an uploaded image!
      Timeout: 15
      Handler: index.handler
      Runtime: nodejs8.10
      MemorySize: 1024
      ReservedConcurrentExecutions: 500
      Environment:
        Variables:
          DST_BUCKET: !Ref 'DestinationBucket'
Parameters:
  DestinationBucket:
    Type: String
    Description: Enter the destination bucket for the thumbnail here!
  CodeBucket:
    Type: String
    Description: Enter the bucket name where you uploaded your Lambda function ZIP
      file.
  LambdaFileName:
    Type: String
    Description: Enter the file name of the Lambda function ZIP file.
    Default: lambda_function.zip