template.yml

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Resources:

  Lambda:
    Type: AWS::Serverless::Function
    Properties:
      Handler: dist/handler_linux
      Runtime: go1.x
      Tracing: Active

  Role: 
    Type: AWS::IAM::Role
    Properties: 
      AssumeRolePolicyDocument: 
        Version: 2012-10-17
        Statement: 
          - Effect: Allow
            Principal:
              Service: appsync.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies: 
        - PolicyName: allow-access-to-lambda-from-appsync
          PolicyDocument: 
            Version: 2012-10-17
            Statement: 
              - Effect: Allow
                Action: lambda:invokeFunction
                Resource:
                  - !GetAtt [ Lambda, Arn ]
                  - !Join [ '', [ !GetAtt [ Lambda, Arn ], ':*' ] ]

  AppSyncAPI:
    Type: AWS::AppSync::GraphQLApi
    Properties:
      Name: !Join [ -, [ !Ref ParamProjectName, !Ref ParamENV ] ]
      AuthenticationType: API_KEY

  AppSyncSchema:
    Type: AWS::AppSync::GraphQLSchema
    Properties:
      ApiId: !GetAtt [ AppSyncAPI, ApiId ]
      DefinitionS3Location: schema.graphql

  AppSyncDataSource:
    Type: AWS::AppSync::DataSource
    Properties:
      ApiId: !GetAtt [ AppSyncAPI, ApiId ]
      Name: handler
      Type: AWS_LAMBDA
      LambdaConfig:
        LambdaFunctionArn: !GetAtt [ Lambda, Arn ]
      ServiceRoleArn: !GetAtt [ Role, Arn ]

  AppSyncResolverPeople:
    Type: AWS::AppSync::Resolver
    Properties:
      ApiId: !GetAtt [ AppSyncAPI, ApiId ]
      TypeName: Query
      FieldName: people
      DataSourceName: !GetAtt [ AppSyncDataSource, Name ]
      RequestMappingTemplate: '{ "version" : "2017-02-28", "operation": "Invoke", "payload": { "resolve": "query.people", "context": $utils.toJson($context) } }'
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverPerson:
    Type: AWS::AppSync::Resolver
    Properties:
      ApiId: !GetAtt [ AppSyncAPI, ApiId ]
      TypeName: Query
      FieldName: person
      DataSourceName: !GetAtt [ AppSyncDataSource, Name ]
      RequestMappingTemplate: '{ "version" : "2017-02-28", "operation": "Invoke", "payload": { "resolve": "query.person", "context": $utils.toJson($context) } }'
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncResolverFriends:
    Type: AWS::AppSync::Resolver
    Properties:
      ApiId: !GetAtt [ AppSyncAPI, ApiId ]
      TypeName: Person
      FieldName: friends
      DataSourceName: !GetAtt [ AppSyncDataSource, Name ]
      RequestMappingTemplate: '{ "version" : "2017-02-28", "operation": "Invoke", "payload": { "resolve": "field.person.friends", "context": $utils.toJson($context) } }'
      ResponseMappingTemplate: $util.toJson($context.result)

  AppSyncAPIKey:
      Type: AWS::AppSync::ApiKey
      Properties:
        ApiId: !GetAtt [ AppSyncAPI, ApiId ]
        Expires: !Ref ParamKeyExpiration

Parameters:

  ParamProjectName:
    Type: String
  ParamENV:
    Type: String
  ParamKeyExpiration:
    Type: Number

Outputs:

  APIKey:
    Description: API Key
    Value: !GetAtt [ AppSyncAPIKey, ApiKey ]

  GraphQL:
    Description: GraphQL URL
    Value: !GetAtt [ AppSyncAPI, GraphQLUrl ]