Spring Cloud tutorial series six: Distributed Configuration Center Spring Cloud Config (F version)

Introduction

In a distributed system, due to the number of services, in order to facilitate unified management service profile, updated in real time, so they need a distributed configuration center.

github address: https: //github.com/erlieStar/spring-cloud-learning

Set up the configuration repository

Configuring placed in https://github.com/erlieStar/spring-cloud-learning/ warehouse conf-repo directory

Put a javashitang service of three environmental profile

Jvshitng-Devkyml

from: javashitang-git-dev

Jvshitng-Testkyml

from: javashitang-git-test

Jvshitng-Prodkyml

from: javashitang-git-prod

Setting up the Configuration Center

在https://github.com/erlieStar/spring-cloud-learning
示例项目：config-service（spring-cloud-config）
consumer-config-service（spring-cloud-config）

config-service

1. Project configuration is as follows

pom.xml

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-config-server</artifactId>
</dependency>

application.yaml

server:
  port: 8080

spring:
  application:
    name: config-service
  cloud:
    config:
      server:
        git:
          uri: https://github.com/erlieStar/spring-cloud-learning # 配置github地址
          search-paths: config-repo # 仓库的相对地址
          username: # github仓库的账号，公有仓库可以不用配置
          password: # github仓库的密码，公有仓库可以不用配置
      label: master # 配置仓库的分支

2. Start class add comments @EnableConfigServer

@EnableConfigServer
@SpringBootApplication
public class ConfigService {

    public static void main(String[] args) {
        SpringApplication.run(ConfigService.class);
    }
}

consumer-config-service

1. Project configuration is as follows

pom.xml

<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-config</artifactId>
</dependency>

bootstrap.yaml

server:
  port: 8090

spring:
  application:
    name: javashitang # 要获取的配置的应用名
  cloud:
    config:
      uri: http://localhost:8080 # 配置中心config-server的地址
      profile: dev # 对应配置文件中的{profile}部分
      label: master # 对应配置文件中的{label}部分，git即分支名

启动config-service（spring-cloud-config）
consumer-config-service（spring-cloud-config）

Repository configuration files will be converted into Web interfaces, access can refer to the following rules:

• /{application}/{profile}[/{label}]
• /{application}-{profile}.yml
• /{label}/{application}-{profile}.yml
• /{application}-{profile}.properties
• /{label}/{application}-{profile}.properties

The above URL mapped {application} - {profile} .yml corresponding profile, wherein the corresponding {label} Git on different branches, the default is master. In javashitang-dev.yml as an example, its application is javashitang, profile is dev.

Visit http: // localhost: 8080 / javashitang / dev
results are as follows, configured to provide normal service center

{
    "name": "javashitang",
    "profiles": [
        "dev"
    ],
    "label": null,
    "version": "2040b0fe167c8641f1c0d8f5e8844e4f35f80896",
    "state": null,
    "propertySources": [
        {
            "name": "https://github.com/erlieStar/spring-cloud-learning/config-repo/javashitang-dev.yaml",
            "source": {
                "from": "javashitang-git-dev"
            }
        }
    ]
}

Visit http: // localhost: 8090 / from
the following results

javashitang-git-dev

Dynamic refresh configuration

We content javashitang-dev.yaml changed as follows, and submit to github

from: javashitang-git-dev-update

Again go to http: // localhost: 8090 / from
the following results

javashitang-git-dev

You can not get to see the latest configuration, how to get the client to get the latest configuration? Only the need for reform on the basis of consumer-config-service (spring-cloud-config) on.

1. Add dependence

pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

2. The need to give top class load variables plus @RefreshScope notes, access / actuator / refresh the client will be updated when following these variable values.

@RefreshScope
@RestController
@SpringBootApplication
public class ConsumerConfigService {

    public static void main(String[] args) {
        SpringApplication.run(ConsumerConfigService.class);
    }

    @Value("${from}")
    private String from;

    @RequestMapping("from")
    public String from() {
        return this.from;
    }
}

Increase follows 3.bootstrap.yaml

management:
  endpoints:
    web:
      exposure:
        include: refresh

4. Use the postman calls with post http way: // localhost: 8090 / actuator / refresh

Again go to http: // localhost: 8090 / from
the following results

javashitang-git-dev-update

We can see that the client has got the latest value. However, each manual refresh client too much, as long as there is no way to submit code to automatically call clients to update it, Github is a way of Webhook

Webhook

Webhook when an event occurs, the notification information to the recipient by sending an HTTP POST request. Webhook you to monitor events on the Github.com, the most common way to push events. If you set up a monitoring events Webhook push, so whenever you have any commits to the project, this Webhook will be triggered, then Github will send a HTTP POST request to the address you configured.

In this way, you will be able to automate some repetitive work this way, for example, you can automatically trigger a number of continuous integration (CI) operation with Webhook tools, such as Travis CI; or is deployed you go through Webhook online server. The figure is above Webhook Github configuration.

• Payload URL: after triggering the callback URL
• Content type: data format, two general use json
• Secret: used to encrypt the body of the POST string. Using HMAC
• events: a list of event triggers.

events event type	description
push	Triggered when push warehouse. Default Event
create	Fires when there is a branch or tag is created
delete	Fires when there is a branch or tag is deleted

So that we can take advantage of the hook mechanism to trigger the update client, but when more and more clients when, elegant hook mechanism is not enough, the other in increments of client needs change hook it is unrealistic. In fact, Spring Cloud gives us a better solution --Spring Cloud Bus. We will continue to follow learn how to implement a message bus in the manner of notification of configuration change information, to automate the update on the cluster by Spring Cloud Bus.

To build a highly available configuration center

The above example can be seen in the presence of a single point config-service, then we can consider to make a micro-distribution center service, which clustered.

示例项目：config-cluster（spring-cloud-config）
consumer-config-cluster（spring-cloud-config）

config-cluster

1. Project configuration is as follows

pom.xml

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-config-server</artifactId>
</dependency>

application.yaml

server:
  port: 9080

spring:
  application:
    name: config-service
  cloud:
    config:
      server:
        git:
          uri: https://github.com/erlieStar/spring-cloud-learning # 配置github地址
          search-paths: config-repo # 仓库的相对地址
          username: # github仓库的账号，公有仓库可以不用配置
          password: # github仓库的密码，公有仓库可以不用配置
      label: master # 配置仓库的分支

eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka

Plus @EnableEurekaClient and @EnableConfigServer comment on 2. Start class

@EnableEurekaClient
@EnableConfigServer
@SpringBootApplication
public class ConfigCluster {

    public static void main(String[] args) {
        SpringApplication.run(ConfigCluster.class);
    }
}

consumer-config-cluster

1. Project configuration is as follows

pom.xml

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-config</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

bootstrap.yaml

server:
  port: 9090

spring:
  application:
    name: javashitang # 要获取的配置的应用名
  cloud:
    config:
      # uri: http://localhost:8080 # 配置中心config-server的地址
      profile: dev # 对应配置文件中的{profile}部分
      label: master # 对应配置文件中的{label}部分
      discovery:
        enabled: true
        service-id: config-cluster

eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka

management:
  endpoints:
    web:
      exposure:
        include: refresh

Plus @EnableEurekaClient and @RefreshScope comment on 2. Start class

@RefreshScope
@RestController
@EnableEurekaClient
@SpringBootApplication
public class ConsumerConfigCluster {

    public static void main(String[] args) {
        SpringApplication.run(ConsumerConfigCluster.class);
    }

    @Value("${from}")
    private String from;

    @RequestMapping("from")
    public String from() {
        return this.from;
    }
}

启动eureka-service（spring-cloud-eureka）
config-cluster（spring-cloud-config）
consumer-config-cluster（spring-cloud-config）

Visit http: // localhost: 9080 / javashitang / dev
results are as follows, configured to provide normal service center

{
    "name": "javashitang",
    "profiles": [
        "dev"
    ],
    "label": null,
    "version": "0760c0643488f25bfba1cf95b5af51006e0f312a",
    "state": null,
    "propertySources": [
        {
            "name": "https://github.com/erlieStar/spring-cloud-learning/config-repo/javashitang-dev.yaml",
            "source": {
                "from": "javashitang-git-dev-update"
            }
        }
    ]
}

Visit http: // localhost: 9090 / from
the following results

javashitang-git-dev-update

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