AWS SAM Template for Video Processing Lambda

template.yaml

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Description: >
  SAM project for Medium article about uploading and processing videos

Parameters:
  EnvironmentValue:
    AllowedValues:
      - "staging"
      - "production"
    Default: "staging"
    Description: "What environment is this?"
    Type: String

Mappings:
  Environments:
    staging:
      APIHOSTNAME: api-staging.example.com.br
      LAMBDASHAREDSECRET: your-super-secret-shared-key
    production:
      APIHOSTNAME: api.example.com.br
      LAMBDASHAREDSECRET: your-super-secret-shared-key

Resources:
  VideoDerivativeGenerator:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: src/video_derivative_generator
      Handler: index.handler
      Runtime: nodejs12.x
      MemorySize: 3008
      Timeout: 600
      Environment:
        Variables:
          VIDEO_MIME_TYPE: video/mp4
          LAMBDA_SHARED_SECRET:
            !FindInMap [Environments, !Ref EnvironmentValue, LAMBDASHAREDSECRET]
          OUTPUT_BUCKET: !Sub "example-${EnvironmentValue}-videos"
          API_HOSTNAME:
            !FindInMap [Environments, !Ref EnvironmentValue, APIHOSTNAME]
      Policies:
        - AWSLambdaExecute # Managed Policy
        - Version: "2012-10-17" # Policy Document
          Statement:
            - Effect: Allow
              Action:
                - logs:CreateLogGroup
                - logs:CreateLogStream
                - logs:PutLogEvents
                - s3:*
              Resource: "*"
      Events:
        VideoUploaded:
          Type: S3
          Properties:
            Bucket:
              Ref: VideosBucket
            Events:
              - "s3:ObjectCreated:*"
            Filter:
              S3Key:
                Rules:
                  - Name: prefix
                    Value: uploads/
      Layers:
        - arn:aws:lambda:<your-aws-region>:<your-aws-account-id>:layer:ffmpeg:1

  VideosBucket:
    Type: "AWS::S3::Bucket"
    Properties:
      BucketName: !Sub "example-${EnvironmentValue}-videos"
      AccelerateConfiguration:
        AccelerationStatus: Enabled