Tags: spring, spring-boot, microservices, spring-cloud, cloud, config-service

Setting Up Config Service

Introduction

Centralized configuration is central (no pun intended) in achieving a successful microservices architecture. Spring Cloud supports this via:

spring-cloud-config-server: a super easy way to set up your config server
spring-cloud-starter-config: easy plug-in dependency to set up your client to retrieve configuration from the server.

Config History

A good practice to preserve config evolution is to store it in a version control system. In this example, we’ll use git to host our configurations.

Setting up Config Git

# change the below directory to where you want to set up your git
mkdir -p /Users/macpro/git/config
cd /Users/macpro/git/config

git init

vim reservation-service.properties

## Add the below to reservation-service.properties
server.port=${PORT:8000}
## reservation-service.properties host configuration for a service named reservation-service

git add reservation-service.properties
git commit -m "Add reservation-service.properties"

NOTE: You need to commit your config changes in order for Spring Config Server to reflect the latest config.

Setting up Config Server

Go to https://start.spring.io/
Type config-service as the “Artifact” name, add Config Server dependencies, and “Generate Project”:
Open the project in your favorite Java IDE (mine is IntelliJ)

Add @EnableConfigServer in src/main/java/ConfigServiceApplication:

 package com.example.configservice;
    
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.config.server.EnableConfigServer;
    
 @EnableConfigServer
 @SpringBootApplication
 public class ConfigServiceApplication {
    
 	public static void main(String[] args) {
 		SpringApplication.run(ConfigServiceApplication.class, args);
 	}
 }

in application.properties, add the below:

 server.port=8888
    
 # CHANGEME: Change the below with your actual config's git location
 spring.cloud.config.server.git.uri=/Users/macpro/git/config

Run ConfigServiceApplication and voila! Your config server is started!
You can check the following URL to see what config is there for reservation-service: http://localhost:8888/reservation-service/default

THINGS TO NOTE:

It’s just so convenient to bootstrap a fully functioning config server by just a single annotation!
Port 8888 is defined in server.port property in application.properties.
reservation-service corresponds to the file name of the properties file in the config’s git and subsequently the microservice name.
I highly recommend JSONView Chrome Extension to view JSON nicely in your Chrome.
In a later tutorial, you’ll see how you can consume this configuration from another spring boot application. You will also be able to modify properties on-the-fly, that is, without restarting neither the consuming (client) service nor the config service itself. A git commit is all you need.
Finally, in actual production, you probably would want to protect your config service (e.g. using BASIC credentials), serve it via HTTPS, or even cipher sensitive texts such as passwords. Don’t worry, Spring’s config service supports all of that. It just takes a bit more configuration & further reading.

References:

https://spring.io/guides/gs/centralized-configuration/

Next Up

Setting Up Eureka Service (Service Discovery & Registration)

Microservices with Spring Boot & Spring Cloud

Part II: Setting Up Config Service