template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: sample script to demo dynamodb streams functionality

Resources:
  
  DynamoDBTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: !Ref APIName
      ProvisionedThroughput:
        WriteCapacityUnits: 5
        ReadCapacityUnits: 5
      AttributeDefinitions:
        - AttributeName: "pk1"
          AttributeType: "S"
        - AttributeName: "sk1"
          AttributeType: "S"
      KeySchema:
        - AttributeName: "pk1"
          KeyType: "HASH"
        - AttributeName: "sk1"
          KeyType: "RANGE"

  RoleAppSyncCloudWatch:
    Type: AWS::IAM::Role
    Properties:
      ManagedPolicyArns:
        - "arn:aws:iam::aws:policy/service-role/AWSAppSyncPushToCloudWatchLogs"
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sts:AssumeRole
            Principal:
              Service:
                - appsync.amazonaws.com

  RoleAppSyncDynamoDB:
    Type: AWS::IAM::Role
    Properties:
      ManagedPolicyArns:
        - !Ref PolicyDynamoDB
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sts:AssumeRole
            Principal:
              Service:
                - appsync.amazonaws.com

  PolicyDynamoDB:
    Type: AWS::IAM::ManagedPolicy
    Properties:
      Path: /service-role/
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - dynamodb:Query
              - dynamodb:GetItem
              - dynamodb:PutItem
              - dynamodb:DeleteItem
            Resource:
              - !Sub arn:aws:dynamodb:${AWS::Region}:${AWS::AccountId}:table/${DynamoDBTable}

  GraphQLApi:
    Type: AWS::AppSync::GraphQLApi
    Properties:
      Name: !Ref APIName
      AuthenticationType: API_KEY
      LogConfig:
        CloudWatchLogsRoleArn: !GetAtt RoleAppSyncCloudWatch.Arn
        ExcludeVerboseContent: FALSE
        FieldLogLevel: ALL

  GraphQLApiSchema:
    Type: AWS::AppSync::GraphQLSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      Definition: |
        schema {
          query: Query
          mutation: Mutation
        }

        type Data {
          data: [AWSJSON]
          pk1: String
          sk1: String
        }

        type DataCollection {
          items: [Data]
          nextToken: String
        }

        input WriteDataInput {
          pk1: String!
          sk1: String!
          data: [AWSJSON]!
        }

        input UpdateDataInput {
          pk1: String!
          sk1: String!
          data: [AWSJSON]!
        }

        type Mutation {
          writeData(input: WriteDataInput!): Data
          updateData(input: UpdateDataInput!): Data
          deleteData(pk1: String!, sk1: String!): Data
        }

        type Query {
          readData(pk1: String!, sk1: String!): Data
          readAllPKData(pk1: String!): DataCollection
        }
  
  GraphQLDataSource:
    Type: AWS::AppSync::DataSource
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      Name: !Ref APIName
      Type: AMAZON_DYNAMODB
      ServiceRoleArn: !GetAtt RoleAppSyncDynamoDB.Arn
      DynamoDBConfig: 
        TableName: !Ref DynamoDBTable
        AwsRegion: !Sub ${AWS::Region}

  AppSyncResolverReadData:
    Type: AWS::AppSync::Resolver
    DependsOn: GraphQLApiSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      TypeName: Query
      FieldName: readData
      DataSourceName: !GetAtt GraphQLDataSource.Name
      RequestMappingTemplate: >
        {
          "version": "2017-02-28",
          "operation": "GetItem",
          "key": {
            "pk1": $util.dynamodb.toDynamoDBJson($ctx.args.pk1),
            "sk1": $util.dynamodb.toDynamoDBJson($ctx.args.sk1),
          },
        }
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverReadAllPKData:
    Type: AWS::AppSync::Resolver
    DependsOn: GraphQLApiSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      TypeName: Query
      FieldName: readAllPKData
      DataSourceName: !GetAtt GraphQLDataSource.Name
      RequestMappingTemplate: >
        {
            "version" : "2017-02-28",
            "operation" : "Query",
            "query" : {
                "expression": "pk1 = :pk1",
                "expressionValues" : {
                    ":pk1" : $util.dynamodb.toDynamoDBJson($ctx.args.pk1),
                }
            }
        }
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverWriteData:
    Type: AWS::AppSync::Resolver
    DependsOn: GraphQLApiSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      TypeName: Mutation
      FieldName: writeData
      DataSourceName: !GetAtt GraphQLDataSource.Name
      RequestMappingTemplate: >
        {
          "version": "2017-02-28",
          "operation": "PutItem",
          "key": {
            "pk1": $util.dynamodb.toDynamoDBJson($ctx.args.input.pk1),
            "sk1": $util.dynamodb.toDynamoDBJson($ctx.args.input.sk1),
          },
          "attributeValues": $util.dynamodb.toMapValuesJson($ctx.args.input),
          "condition": {
            "expression": "attribute_not_exists(#pk1) AND attribute_not_exists(#sk1)",
            "expressionNames": {
              "#pk1": "pk1",
              "#sk1": "sk1",
            },
          },
        }
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverUpdateData:
    Type: AWS::AppSync::Resolver
    DependsOn: GraphQLApiSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      TypeName: Mutation
      FieldName: updateData
      DataSourceName: !GetAtt GraphQLDataSource.Name
      RequestMappingTemplate: >
        {
          "version": "2017-02-28",
          "operation": "PutItem",
          "key": {
            "pk1": $util.dynamodb.toDynamoDBJson($ctx.args.input.pk1),
            "sk1": $util.dynamodb.toDynamoDBJson($ctx.args.input.sk1),
          },
          "attributeValues": $util.dynamodb.toMapValuesJson($ctx.args.input),
        }
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverDeleteData:
    Type: AWS::AppSync::Resolver
    DependsOn: GraphQLApiSchema
    Properties:
      ApiId: !GetAtt GraphQLApi.ApiId
      TypeName: Mutation
      FieldName: deleteData
      DataSourceName: !GetAtt GraphQLDataSource.Name
      RequestMappingTemplate: >
        {
          "version": "2017-02-28",
          "operation": "DeleteItem",
          "key": {
            "pk1": $util.dynamodb.toDynamoDBJson($ctx.args.pk1),
            "sk1": $util.dynamodb.toDynamoDBJson($ctx.args.sk1),
          },
        }
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncAPIKey:
      Type: AWS::AppSync::ApiKey
      Properties:
        ApiId: !GetAtt GraphQLApi.ApiId
        Expires: !Ref APIKeyExpiration

Parameters:
  APIName:
    Type: String
  APIKeyExpiration:
    Type: Number

Outputs:
  APIKey:
    Description: API Key
    Value: !GetAtt AppSyncAPIKey.ApiKey

  GraphQL:
    Description: GraphQL URL
    Value: !GetAtt GraphQLApi.GraphQLUrl