1 前言
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可配置是一個(gè)成熟軟件系統(tǒng)應(yīng)該提供的特性,而配置管理對(duì)于大型系統(tǒng)就顯得十分重要,特別是對(duì)于擁有多個(gè)應(yīng)用的微服務(wù)系統(tǒng)??上驳氖?,Spring為我們提供了很好的配置管理,如Springboot的配置就很強(qiáng)大。對(duì)于Spring Cloud,就有強(qiáng)大的Spring Cloud Config,在提供了一個(gè)在應(yīng)用之外的配置管理,如文件或Git倉(cāng)庫(kù),對(duì)分布式系統(tǒng)配置管理十分有益。
2 快速體驗(yàn)
Spring Cloud Config服務(wù)端就是一個(gè)Springboot應(yīng)用,啟動(dòng)、部署都十分簡(jiǎn)單。
整體的架構(gòu)如下圖所示:

2.1 服務(wù)端就是一個(gè)Springboot
在Springboot中添加依賴(lài)如下:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
<version>2.2.0.RELEASE</version>
</dependency>
只需要一個(gè)就行了,它已經(jīng)包含了web和actuator。
添加Java主類(lèi):
package com.pkslow.config;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;
@SpringBootApplication
@EnableConfigServer
public class ConfigServer {
public static void main(String[] args) {
SpringApplication.run(ConfigServer.class,args);
}
}
跟普通的Springboot應(yīng)用相比只是多了一個(gè)注解@EnableConfigServer而已。
2.2 配置倉(cāng)庫(kù)
通過(guò)我們會(huì)把配置通過(guò)版本控制管理起來(lái),一般使用Git倉(cāng)庫(kù),為簡(jiǎn)單展示使用本地倉(cāng)庫(kù)如下:
# 創(chuàng)建目錄
mkdir git-repo
# 初始化一個(gè)git目錄
git init
# 新建文件
touch application.properties
# 添加變更
git add .
# 提交變更
git commit -m "init"
配置一下項(xiàng)目的application.properties,注意是Config Server項(xiàng)目的,而不是在git-repo目錄里的:
server.port=8888
spring.application.name=config-server
spring.cloud.config.server.git.uri=/Users/pkslow/IdeaProjects/pkslow-modules/config-server/git-repo
接著就可以啟動(dòng)Config Server了。
但git倉(cāng)庫(kù)里的配置文件沒(méi)有什么內(nèi)容,我們加入以下內(nèi)容并提交(必須要提交,不然無(wú)法獲?。?/p>
pkslow.webSite=www.pkslow.com
pkslow.age=18
pkslow.email=admin@pkslow.com
2.3 配置路徑匹配
那我們?nèi)绾潍@取這些配置呢?可以通過(guò)以下URL讀?。?/p>
/{application}/{profile}[/{label}]
/{application}-{profile}.yml
/{label}/{application}-{profile}.yml
/{application}-{profile}.properties
/{label}/{application}-{profile}.properties
label指的是代碼分支,如master,feature-1等。application是應(yīng)用的名字,在以后客戶端讀取會(huì)用到。profile一般用于指定環(huán)境,如prod,dev,uat等。
所以,我們可以用以下URL來(lái)獲取我們剛添加的配置信息:
http://localhost:8888/application/default
http://localhost:8888/application/default/master
http://localhost:8888/master/application.properties
http://localhost:8888/application-default.properties
訪問(wèn)如下:
$ curl http://localhost:8888/application/default/master
{"name":"application","profiles":["default"],"label":"master","version":"8796f39b35095f6e9b7176457eb03dd6d62b1783","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/git-repo/application.properties","source":{"pkslow.webSite":"www.pkslow.com","pkslow.age":"18","pkslow.email":"admin@pkslow.com"}}]}
最后一個(gè)地址/{label}/{application}-{profile}.properties的返回結(jié)果格式不同,直接返回配置文件內(nèi)容:
$ curl http://localhost:8888/application-default.properties
pkslow.age: 18
pkslow.email: admin@pkslow.com
pkslow.webSite: www.pkslow.com
如果我們先建一個(gè)分支release-20200809,并修改age為實(shí)際年齡9,則如下:
$ curl http://localhost:8888/application/default/release-20200809
{"name":"application","profiles":["default"],"label":"release-20200809","version":"7e27e6972ed31ee1a51e9277a2f5c0a628cec67a","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/git-repo/application.properties","source":{"pkslow.webSite":"www.pkslow.com","pkslow.age":"9","pkslow.email":"admin@pkslow.com"}}]}
可以看到對(duì)應(yīng)的pkslow.age已經(jīng)變?yōu)?code>9了,但訪問(wèn)/application/default/master則還是18,分支之間不會(huì)相互影響。
2.4 遠(yuǎn)程倉(cāng)庫(kù)
本地倉(cāng)庫(kù)只是為了簡(jiǎn)單展示,在實(shí)際項(xiàng)目中,一般使用遠(yuǎn)程倉(cāng)庫(kù),在GitHub創(chuàng)建一個(gè)新的倉(cāng)庫(kù)如下:

特意創(chuàng)建了個(gè)private的倉(cāng)庫(kù)來(lái)檢測(cè)后面的鑒權(quán)是否正確。
重新配置倉(cāng)庫(kù)的地址如下:
spring.cloud.config.server.git.uri=https://github.com/pkslow/pkslow-config
spring.cloud.config.server.git.username=admin@pkslow.com
spring.cloud.config.server.git.password=***
spring.cloud.config.server.git.default-label=master
spring.cloud.config.server.git.search-paths=demo
創(chuàng)建一個(gè)demo目錄來(lái)放置配置,所以search-paths配置為demo。完成配置重啟服務(wù)器,就可以正常讀取遠(yuǎn)程倉(cāng)庫(kù)的配置了。
2.5 多個(gè)代碼配置倉(cāng)庫(kù)
有些時(shí)候,我們的配置可能并不只在一個(gè)倉(cāng)庫(kù)里,而是在各自客戶端的代碼庫(kù)中,比如我們有以下三個(gè)服務(wù):
- (1)服務(wù)發(fā)現(xiàn):discovery,代碼庫(kù)pkslow-discovery-service
- (2)API網(wǎng)關(guān):gateway,代碼庫(kù)pkslow-gateway-service
- (3)訂單服務(wù):order,代碼庫(kù)pkslow-order-service
它們各自的配置文件都放在各自的代碼庫(kù)里,那就需要配置多個(gè)代碼庫(kù)。我們還多配置一個(gè)默認(rèn)的配置庫(kù)pkslow-default,如果匹配不到,就會(huì)選擇默認(rèn)代碼庫(kù)的配置。具體配置如下:
server:
port: 8888
spring:
application:
name: config-server
cloud:
config:
server:
git:
uri: /Users/pkslow/multiple-repos/pkslow-default
repos:
pkslow-discovery-service:
pattern: pkslow-discovery-*
cloneOnStart: true
uri: /Users/pkslow/multiple-repos/pkslow-discovery-service
search-paths: config
pkslow-gateway-service:
pattern: pkslow-gateway-*/dev
cloneOnStart: true
uri: /Users/pkslow/multiple-repos/pkslow-gateway-service
search-paths: config
pkslow-order-service:
pattern: pkslow-order-*
cloneOnStart: true
uri: /Users/pkslow/IdeaProjects/pkslow-order-service
search-paths: config
可以各自定義配置文件所放的目錄search-paths,不配置默認(rèn)為根目錄。
這里的pattern的配置規(guī)則是{application}/{profile},支持正則符號(hào)*。注意只匹配一個(gè)結(jié)果,如果都滿足,只取第一個(gè)匹配的倉(cāng)庫(kù)。
啟動(dòng)后我們來(lái)看看配置結(jié)果:
# 默認(rèn)profile和label,正確匹配
$ curl http://localhost:8888/pkslow-order-service/default/master
{"name":"pkslow-order-service","profiles":["default"],"label":"master","version":"9d86e5d11974f0a0e7c20cd53d8f062755193e70","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-order-service/config/application.properties","source":{"pkslow.webSite":"www.pkslow.com","pkslow.app.name":"order-service"}}]}
# 正確匹配,但不存在的Label,配置庫(kù)沒(méi)有對(duì)應(yīng)代碼分支,404
$ curl http://localhost:8888/pkslow-order-service/default/release
{"timestamp":"2020-08-13T06:58:38.722+0000","status":404,"error":"Not Found","message":"No such label: release","path":"/pkslow-order-service/default/release"}
# profile為dev,正確匹配
$ curl http://localhost:8888/pkslow-order-service/dev/master
{"name":"pkslow-order-service","profiles":["dev"],"label":"master","version":"9d86e5d11974f0a0e7c20cd53d8f062755193e70","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-order-service/config/application.properties","source":{"pkslow.webSite":"www.pkslow.com","pkslow.app.name":"order-service"}}]}
# 對(duì)于gateway只能匹配profile=dev,無(wú)法匹配,讀取默認(rèn)配置
$ curl http://localhost:8888/pkslow-gateway-service/default/master
{"name":"pkslow-gateway-service","profiles":["default"],"label":"master","version":"8358f2b4701fac21a0c7776bc46cec6d9442c549","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-base/application.properties","source":{"pkslow.birthDate":"2020-08-10"}}]}
# 對(duì)于gateway只能匹配profile=dev,正確匹配
$ curl http://localhost:8888/pkslow-gateway-service/dev/master
{"name":"pkslow-gateway-service","profiles":["dev"],"label":"master","version":"1a4e26849b237dc2592ca0d391daaa1a879747d2","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-gateway-service/config/application.properties","source":{"pkslow.webSite":"www.pkslow.com","pkslow.app.name":"gateway-service"}}]}
# 不存在的服務(wù)名,無(wú)法匹配,讀取默認(rèn)配置
$ curl http://localhost:8888/unknown-service/dev/master
{"name":"unknown-service","profiles":["dev"],"label":"master","version":"8358f2b4701fac21a0c7776bc46cec6d9442c549","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-base/application.properties","source":{"pkslow.birthDate":"2020-08-10"}}]}
3 客戶端使用配置
經(jīng)過(guò)前面的例子我們已經(jīng)了解到服務(wù)端如何從代碼庫(kù)里獲取配置,但始終還是要使客戶端能獲取到對(duì)應(yīng)的配置并產(chǎn)生效果。我們來(lái)演示一下。
3.1 項(xiàng)目準(zhǔn)備
搭建一個(gè)最簡(jiǎn)單的Springboot Web項(xiàng)目,并加上Spring Cloud Config的支持,添加依賴(lài)如下:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
添加配置文件:bootstrap.properties(雖然我們要從服務(wù)端讀取配置,但有些配置還是必須在客戶添加的,如服務(wù)端地址),內(nèi)容如下:
server.port=8080
spring.application.name=pkslow-gateway-service
spring.cloud.config.uri=http://localhost:8888
在這里我們配置了客戶端的端口、服務(wù)端的地址以及客戶端應(yīng)用的名字,這個(gè)名字是非常關(guān)鍵的,待會(huì)講解。
添加Controller來(lái)暴露API以顯示讀到的配置內(nèi)容:
@RestController
public class PkslowController {
@Value("${pkslow.age}")
private Integer age;
@Value("${pkslow.email}")
private String email;
@Value("${pkslow.webSite}")
private String webSite;
@GetMapping("/pkslow")
public Map<String, String> getConfig() {
Map<String, String> map = new HashMap<>();
map.put("age", age.toString());
map.put("email", email);
map.put("webSite", webSite);
return map;
}
}
接著啟動(dòng)客戶端即可,訪問(wèn)結(jié)果如下:
$ curl http://localhost:8080/pkslow
{"webSite":"default.pkslow.com","age":"9","email":"admin@pkslow.com"}
這些配置內(nèi)容并不在客戶端,說(shuō)明可以從服務(wù)端獲取到配置信息了。
3.2 客戶端如何匹配
客戶端已經(jīng)獲取到配置信息了,那是否正確呢?客戶端又是怎樣匹配的呢?其實(shí)前面的內(nèi)容已經(jīng)提及,主要通過(guò)三個(gè)信息來(lái)匹配:
label指的是代碼分支。application是應(yīng)用的名字。profile一般用于指定環(huán)境。
上個(gè)例子客戶端名字為pkslow-gateway-service;label沒(méi)指定,默認(rèn)為master;profile沒(méi)有指定,默認(rèn)為default。
我們?cè)诜?wù)端匹配規(guī)則為pattern: pkslow-gateway-*/dev,所以可以匹配名字,但無(wú)法匹配profile,因此讀取了默認(rèn)倉(cāng)庫(kù)的配置:
$ cat pkslow-base/application.properties
pkslow.webSite=default.pkslow.com
pkslow.age=9
pkslow.email=admin@pkslow.com
修改一下客戶端的配置,配置profile為dev如下:
server.port=8080
spring.application.name=pkslow-gateway-service
spring.profiles.active=dev
spring.cloud.config.uri=http://localhost:8888
再次獲取客戶端的配置如下:
$ curl http://localhost:8080/pkslow
{"webSite":"gateway-master.pkslow.com","age":"9","email":"admin@pkslow.com"}
可見(jiàn)已經(jīng)讀取到pkslow-gateway-service倉(cāng)庫(kù)的配置內(nèi)容了:
$ cat pkslow-gateway-service/config/application.properties
pkslow.webSite=gateway-master.pkslow.com
pkslow.age=9
pkslow.email=admin@pkslow.com
在pkslow-gateway-service倉(cāng)庫(kù)新建代碼分支release并添加配置,再修改客戶端配置如下:
server.port=8080
spring.application.name=pkslow-gateway-service
spring.profiles.active=dev
spring.cloud.config.label=release
spring.cloud.config.uri=http://localhost:8888
重啟后再次訪問(wèn),正確讀取到了新分支的配置:
$ curl http://localhost:8080/pkslow
{"webSite":"gateway-release.pkslow.com","age":"9","email":"admin@pkslow.com"}
3.3 客戶端配置生效問(wèn)題
當(dāng)我們修改配置后,再次訪問(wèn)結(jié)果如下:
$ git commit -a -m "update"
[release 0e489fe] update
1 file changed, 2 insertions(+), 2 deletions(-)
$ curl http://localhost:8888/pkslow-gateway-service/dev/release
{"name":"pkslow-gateway-service","profiles":["dev"],"label":"release","version":"0e489fec5de73b1a6d11befa3f65e44836979e23","state":null,"propertySources":[{"name":"/Users/pkslow/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-gateway-service/config/application.properties","source":{"pkslow.webSite":"gateway-release.pkslow.com","pkslow.age":"10","pkslow.email":"admin@pkslow.com"}}]}
$ curl http://localhost:8080/pkslow
{"webSite":"gateway-release.pkslow.com","age":"9","email":"admin@pkslow.com"}
結(jié)果發(fā)現(xiàn),服務(wù)端已經(jīng)生效了,但客戶端并沒(méi)有。這是因?yàn)樵谶@種模式下客戶端只會(huì)在啟動(dòng)的時(shí)候讀取配置使其生效。如果想要客戶端也生效,我們要使用Springboot actuator提供的/refresh端點(diǎn)才行。
先添加actuator依賴(lài):
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
配置要保證/refresh可以訪問(wèn),添加如下配置:
management.endpoints.web.exposure.include=refresh
指定刷新的范圍,在Controller上添加注解@RefreshScope如下:
@RefreshScope
@RestController
public class PkslowController {
//xxx
}
重啟應(yīng)用。操作及效果如下:
# 修改配置并提交
$ git commit -a -m "update age to 18"
[release fc863bd] update age to 18
1 file changed, 1 insertion(+), 1 deletion(-)
# 服務(wù)端配置生效
$ curl http://localhost:8888/pkslow-gateway-service/dev/release
{"name":"pkslow-gateway-service","profiles":["dev"],"label":"release","version":"fc863bd8849fa1dc5eaf2ce0a97afb485f81c2f0","state":null,"propertySources":[{"name":"/Users/larry/IdeaProjects/pkslow-modules/config-server/multiple-repos/pkslow-gateway-service/config/application.properties","source":{"pkslow.webSite":"gateway-release.pkslow.com","pkslow.age":"18","pkslow.email":"admin@pkslow.com"}}]}
# 客戶端沒(méi)有生效
$ curl http://localhost:8080/pkslow
{"webSite":"gateway-release.pkslow.com","age":"10","email":"admin@pkslow.com"}
# 發(fā)送POST請(qǐng)求到客戶端/refresh
$ curl -X POST http://localhost:8080/actuator/refresh
["config.client.version","pkslow.age"]
# 客戶端已經(jīng)生效
$ curl http://localhost:8080/pkslow
{"webSite":"gateway-release.pkslow.com","age":"18","email":"admin@pkslow.com"}
3.4 自動(dòng)更新配置
每次提交代碼配置后,都需要手動(dòng)發(fā)一次POST請(qǐng)求到客戶端才能更新配置,顯然是不夠友好的。GitHub提供了webhook功能,可以在觸發(fā)事件后,發(fā)送請(qǐng)求到指定URL,這樣便可以實(shí)現(xiàn)自動(dòng)更新了。
通過(guò)webhook功能實(shí)現(xiàn)自動(dòng)更新是一對(duì)一的,如果客戶端很多(通常是這種場(chǎng)景),就無(wú)法這樣直接實(shí)現(xiàn)。有兩個(gè)方案:
(1)自己實(shí)現(xiàn)一個(gè)端口來(lái)接受來(lái)自Git的請(qǐng)求,然后再分發(fā)到各個(gè)服務(wù)端。這個(gè)方法比較麻煩,不是很推薦。
(2)通過(guò)引入Spring Cloud Bus來(lái)刷新多個(gè)客戶端。但需要引入MQ,如kafka或RabbitMQ。
3.5 在有服務(wù)發(fā)現(xiàn)時(shí)的不同
在微服務(wù)架構(gòu)中,如果配置服務(wù)端與客戶端都注冊(cè)在服務(wù)發(fā)現(xiàn)(如eureka)上時(shí),客戶端就無(wú)須再配置服務(wù)端的地址了,會(huì)從服務(wù)發(fā)現(xiàn)中心獲取識(shí)別。這與Springboot Admin在有eureka的情況下有異曲同工之妙。
代碼沒(méi)什么特別之外,就是把服務(wù)端和客戶端同時(shí)注冊(cè)到eureka即可。
4 總結(jié)
本文通過(guò)例子一步步展示如何使用Spring Cloud Config,主要是理解交互過(guò)程和匹配規(guī)則,其它都是代碼細(xì)節(jié),參考官方文檔即可。
關(guān)于配置的一些文章:
Java怎么從這四個(gè)位置讀取配置文件Properties(普通文件系統(tǒng)-classpath-jar-URL)
注解@ConfigurationProperties讓配置整齊而簡(jiǎn)單
Springboot整合Jasypt,讓配置信息安全最優(yōu)雅方便的方式
使用Spring Cloud Config統(tǒng)一管理配置,別再到處放配置文件了
Spring Cloud Config整合Spring Cloud Kubernetes,在k8s上管理配置
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