A CloudFormation template sample to subscribe an AWS Lambda Function to an SQS Queue.

Lambda-SQS-Trigger

---
AWSTemplateFormatVersion: '2010-09-09'

Description: SQS Queue with Lambda Trigger

Parameters:

  LambdaS3BucketName:
    Type: String
    Description: S3 Bucket Name holding the Lambda Function Package

  LambdaS3Key:
    Type: String
    Description: S3 Key to the Lambda Function Package

  LambdaHandler:
    Type: String
    Description: The Lambda Handler

  LambdaDescription:
    Type: String
    Description: Lambda Handler for Cognito Testing

  LambdaRuntime:
    Type: String
    Description: The Lambda Function Runtime
    AllowedValues:
      - dotnetcore2.1
      - go1.x
      - nodejs6.10
      - nodejs8.10
      - java8
      - powershell
      - python2.7
      - python3.6
      - python3.7
      - ruby2.5

  LambdaMemorySize:
    Type: Number
    Description: The Lambda Function Memory Size
    Default: 512
    MinValue: 128
    MaxValue: 3008

  LambdaTimeout:
    Type: Number
    Description: The Lambda Function Timeout in Seconds
    Default: 60
    MinValue: 30
    MaxValue: 900

  PowerShellFunctionHandler:
    Type: String
    Default: ''
    Description: PowerShell Function Name for Lambda Handler. Ignored if Runtime is not set to powershell.

  UsePowerShellFunctionHandler:
    Type: String
    Description: Set to Yes if you require the PowerShell Function Handler
    Default: 'No'
    AllowedValues:
      - 'No'
      - 'Yes'

  SQSQueueArn:
    Type: String
    Description: SQS Queue Arn for the Lambda Function subscription

  SQSBatchSize:
    Type: Number
    Description: The number of SQS Messages to send to the Lambda Function
    Default: 10
    MinValue: 1
    MaxValue: 10

Metadata:

  AWS::CloudFormation::Interface:
    ParameterGroups:
      -
        Label:
          default: AWS Lambda Configuration
        Parameters:
          - LambdaS3BucketName
          - LambdaS3Key
          - LambdaHandler
          - LambdaDescription
          - LambdaRuntime
          - LambdaMemorySize
          - LambdaTimeout
      -
        Label:
          default: PowerShell Lambda
        Parameters:
          - PowerShellFunctionHandler
          - UsePowerShellFunctionHandler
      -
        Label:
          default: SQS Queue Source Trigger
        Parameters:
          - SQSQueueArn
          - SQSBatchSize
    ParameterLabels:
      LambdaS3BucketName:
        default: S3 Bucket Name
      LambdaS3Key:
        default: S3 Key
      LambdaHandler:
        default: Handler
      LambdaDescription:
        default: Description
      LambdaRuntime:
        default: Runtime
      LambdaMemorySize:
        default: Memory Size
      LambdaTimeout:
        default: Timeout
      PowerShellFunctionHandler:
        default: PowerShell Function Handler
      SQSQueueArn:
        default: SQS Queue Arn
      SQSBatchSize:
        default: Batch Size
      UsePowerShellFunctionHandler:
        default: Use PowerShell Function Handler

Conditions:

  IsPowerShellLambda: !Equals [!Ref LambdaRuntime, 'powershell']

  UsePowerShellFunctionHandler: !And
  - !Equals [!Ref LambdaRuntime, 'powershell']
  - !Equals [!Ref UsePowerShellFunctionHandler, 'Yes']

Resources:

  LambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        S3Bucket: !Ref LambdaS3BucketName
        S3Key: !Ref LambdaS3Key
      Description: !Ref LambdaDescription
      Handler: !Ref LambdaHandler
      MemorySize: !Ref LambdaMemorySize
      Environment:
        Variables:
          AWS_POWERSHELL_FUNCTION_HANDLER: !If [UsePowerShellFunctionHandler, !Ref PowerShellFunctionHandler, !Ref 'AWS::NoValue']
      Role: !GetAtt LambdaFunctionRole.Arn
      Runtime: !If [IsPowerShellLambda, 'dotnetcore2.1', !Ref LambdaRuntime]
      Timeout: !Ref LambdaTimeout

  LambdaFunctionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action: 'sts:AssumeRole'
      Path: /
      Policies:
        - PolicyName: LambdaRole
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              -
                Effect: Allow
                Action:
                  - cloudwatch:PutMetricData
                  - logs:CreateLogGroup
                  - logs:CreateLogStream
                  - logs:DescribeLogGroups
                  - logs:DescribeLogStreams
                  - logs:PutLogEvents
                Resource: '*'
              -
                Effect: Allow
                Action:
                  - s3:GetObject*
                  - s3:ListBuckets
                Resource: '*'
              -
                Effect: Allow
                Action:
                  - sqs:GetQueueAttributes
                  - sqs:DeleteMessage
                  - sqs:ReceiveMessage
                Resource: !Ref SQSQueueArn

  LogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub '/aws/lambda/${LambdaFunction}'
      RetentionInDays: 14

  SQSTrigger:
    Type: AWS::Lambda::EventSourceMapping
    DependsOn:
      - LogGroup
    Properties:
      BatchSize: !Ref SQSBatchSize
      Enabled: true
      EventSourceArn: !Ref SQSQueueArn
      FunctionName: !Ref LambdaFunction