api-gateway

Api Gateway

API Gateway is an edge service that provides a single-entry point for certain groups of microservices.

It acts as unified “front door” to our ecosystem.

Additionally, gateway is integrated with Hystrix for fault tolerance(Circuit Breaker) and Eureka for service discovery.

Getting Started

Prerequisites

• Running config-server.
• Running service-registry.
• Running zipkin server.
• Running admin-dashboard.
• Running user-service.
• Running hello-service.

Installation

Start application:

./gradlew bootRun

Usage

• Start service.

• Check available routes in Api Gateway.

• Check if application successfully registered in service-registry.

• Check load balancing.

  # Hello service
  curl "http://localhost:8082/api/v1/hello"
  
  # Users service    
  curl "http://localhost:8082/api/v1/usersusers"
  
  # Hystrix protecting custom route (Example how to use hystrix api in route definition, see RouteConfiguration.java)
  curl "http://localhost:8082/api/v1/hystrix/hello"
  
  # Simulate hystrix failure
  curl "http://localhost:8082/api/v1/hello/hystrix?shouldFail=true"
  
  # Simulate hystrix success
  curl "http://localhost:8082/api/v1/hello/hystrix?shouldFail=false"

• Check Hystrix dashboard:

  • Go to admin-dashboard.
  • Choose 'api-gateway' application.
  • Click 'Hystrix' tab and see visualized hystrix stream e.g.

• Open zipkin ui and investigate traces.

Build

# Clean build jar
./gradlew clean build

# Build docker image
./gradlew jibDockerBuild

Important Endpoints

Name	Endpoint
Api Gateway	http://localhost:8082/
Api Gateway - available routes	http://localhost:8082/actuator/gateway/routes
Api Gateway - Hello service	http://localhost:8082/api/v1/hello
Api Gateway - Users service	http://localhost:8082/api/v1/users
Api Gateway - Custom route behind hystrix using route definition, see RouteConfiguration.java:22	http://localhost:8082/api/v1/hystrix/hello
Api Gateway - Simulate hystrix error in Hello Service	http://localhost:8082/api/v1/hello/hystrix?shouldFail=true
Api Gateway - Simulate hystrix success in Hello Service	http://localhost:8082/api/v1/hello/hystrix?shouldFail=false