CLoudFormation Template for AWS AppSync OpenWeatherMap API

openweathermap-api.yaml

---
Description: GraphQL based OpenWeatherMap API

Parameters:
  APIName:
    Type: String
    Description: Name of the API - used to generate unique names for resources
    MinLength: 3
    MaxLength: 20
    AllowedPattern: '^[a-zA-Z][a-zA-Z0-9_]*$'
  APIKey:
    Type: String
    Description: The API Key for OpenWeatherMap
    MinLength: 32
    MaxLength: 32
    AllowedPattern: '^[a-f0-9]*$'

Resources:
  AppSyncApi:
    Type: "AWS::AppSync::GraphQLApi"
    Description: "The GraphQL API"
    Properties:
      AuthenticationType: "API_KEY"
      Name: !Sub ${APIName}

  AppSyncApiKey:
    Type: "AWS::AppSync::ApiKey"
    Properties:
      Description: "Basic OpenWeatherMap API Key"
      Expires: 1564608763
      ApiId: !GetAtt AppSyncApi.ApiId

  AppSyncSchema:
    Type: "AWS::AppSync::GraphQLSchema"
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      Definition: |
        type Query {
          weatherByCity(city: String!): Weather
        }
        type Weather {
          timestamp: Int
          location: String
          condition: Int
          description: String
          temperature: Float
          pressure: Float
          humidity: Float
          wind_speed: Float
          wind_direction: Int
          cloud_cover: Float
          rain_volume: Float
          snow_volume: Float
        }
        schema {
          query: Query
        }
  AppSyncOpenWeatherMapDataSource:
    Type: "AWS::AppSync::DataSource"
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      Name: openweathermap
      Description: "The OpenWeatherMap Data Source"
      Type: HTTP
      HttpConfig:
        Endpoint: "https://api.openweathermap.org"

  AppSyncWeatherByCityQueryResolver:
    Type: "AWS::AppSync::Resolver"
    DependsOn: AppSyncSchema
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      TypeName: Query
      FieldName: weatherByCity
      DataSourceName: !GetAtt AppSyncOpenWeatherMapDataSource.Name
      RequestMappingTemplate: !Sub |
        {
          "version": "2018-05-29",
          "method": "GET",
          "resourcePath": "/data/2.5/weather",
          "params":{
            "query": {
              "q": "$context.args.city",
              "APPID": "${APIKey}"
            },
            "headers": {
              "Content-Type": "application/json"
            }
          }
        }
      ResponseMappingTemplate: |
        #if($context.result.statusCode == 200)
        ## Success - decode the body and reconstruct the response with the schema in mind
        #set($response = $util.parseJson($context.result.body))
        #set($result = {
          "timestamp": $response.dt,
          "location": $response.name,
          "condition": $response.weather[0].id,
          "description": $response.weather[0].description,
          "temperature": $response.main.temp,
          "pressure": $response.main.pressure,
          "humidity": $response.main.humidity,
          "wind_speed": $response.wind.speed,
          "wind_direction": $response.wind.deg,
          "cloud_cover": $response.clouds.all,
          "rain_volume": $util.defaultIfNullOrEmpty($response.rain["3h"], 0),
          "snow_volume": $util.defaultIfNullOrEmpty($response.rain["3h"], 0)
        })
        $util.toJson($result)
        #else
        ## Error - send the proper error message
        $utils.appendError($ctx.result.body, $ctx.result.statusCode)
        #end

Outputs:
  GraphQLApiEndpoint:
    Description: The URL to the GraphQL Endpoint
    Value: !GetAtt AppSyncApi.GraphQLUrl
  GraphQLApiId:
    Description: The API ID of the GraphQL API
    Value: !GetAtt AppSyncApi.ApiId
  GraphQLApiKey:
    Description: The API Key for the GraphQL API
    Value: !GetAtt AppSyncApiKey.ApiKey