apigateway

apigateway

API Gateway service provides a unified web backend API across all cloudnativedesign microservices for both web and mobile clients using a GraphQL API

It allows :

• schema first design of the API
• effective migration managment for iterative design
• optimized caching of the response objects
• integrated queries across multiple providers
• schema validation on item creation

Service usage

Setting up the service

Download the repository code, initiate the required go module dependencies locally and start the server to set up your local development environment.

git clone https://github.com/cloudnativedesign/apigateway.git

go mod download

go run server.go

Changing the schema

Start by adapting the Types in schema.graphqls along with the required mutations and inputs.

Then compile to generate the model files and the resolver stumps

go run github.com/99designs/gqlgen generate

Complete the code in schema.resolver.go with the custom logic to resolve the request to the abstracted microservice APIs using gRPC calls for internal resolution on service-to-service communication.

Architecture

The service implements the API gateway pattern to help us abstract the complex interactions across multiple backend microservices around a given POJO.

See micoservice Pattern : API Gateway for more details on the pattern

Implementation

The API is designed as a GraphQL API under a schema first approach using code generator frameworks. This allows us to use this touchpoint between microservice backend and UI to quickly iterate over user requirements while reducing the need to reimplement code in the resolvers. See qlgen