Nacos configuration management

Unified configuration management
● Configuration change hot update

The steps of configuration acquisition are as follows ：

1. introduce Nacos The configuration management client depends on ：

<!--nacos The configuration management of depends on -->
 <dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
 </dependency>

2. stay userservice in resource Directory add a bootstrap.yml file , This file is the boot file , Priority over application.yml:

spring:
  application:
    name: userservice
  profiles:
    active: dev # Environmental Science 
  cloud:
    nacos:
      server-addr: 8001 # Address 
      config:
        file-extension: yaml # File suffix 

We are servervice Lieutenant general pattern.dateformat This attribute is injected into UserController Test in

@Slf4j
@RestController
@RequestMapping("/user")
public class UserController {
    

    @Value("${pattern.dateformat}")
    private String dateformat;

    @GetMapping("now")
    public String now(){
    
        return LocalDateTime.now().format(
                DateTimeFormatter.ofPattern(dateformat, Locale.CHINA)
        );
    }
}

Give the configuration to Nacos Management steps ：
① stay Nacos Add profile to
② Introduce... Into microservices nacos Of config rely on
③ Add... To microservices bootstrap.yml, To configure nacos The address of 、 The current environment 、 The service name 、 File suffix . These determine when the program starts nacos Which file to read

Configure auto update

Nacos After the configuration file of is changed , Microservices can sense... Without restarting . However, it needs to be implemented through the following two configurations ：

• Mode one ： stay @Value Add annotation on the class of the injected variable @RefreshScope

@RestController
@RequestMapping("/user")
@RefreshScope
public class UserController {
    

    @Value("${pattern.dateformat}")
    private String dateformat;
    
    @GetMapping("now")
    public String now(){
    
        return LocalDateTime.now().format(
                DateTimeFormatter.ofPattern(dateformat, Locale.CHINA)
        );
    }
}

• Mode two ： Use @ConfigurationProperties annotation

@Data
@Component
@ConfigurationProperties(prefix = "pattern")
public class PatternProperties {
    
    private String dateformat;
}

Nacos After configuration changes , Microservices can achieve hot updates , The way ：
① adopt @Value Annotation injection , combination @RefreshScope To refresh
② adopt @ConfigurationProperties Inject , Automatically refresh

matters needing attention

• Not all configurations fit into the configuration center , Maintenance is more troublesome
• It is suggested that some key parameters , Parameters that need to be adjusted at run time nacos Configuration center , It is generally custom configuration .

Multi environment configuration sharing

The microservice starts from nacos Read multiple configuration files ：

• [spring.application.name]-[spring.profiles.active].yml, for example ：userservice-dev.yml
• [spring.application.name].yml, for example ：userservice.yml
  No matter what profie How to change ,[spring.application.name].yml This file must be loaded , Therefore, the environment sharing configuration can be written to this file .
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Priority of multiple configurations :

• service name -profile.yaml> The service name .yaml> Local configuration
  

Microservices will start from Nacos Read the configuration file ：
① [ service name ]-[profile.active].yaml, Environment configuration
② [ service name ].yaml, The default configuration , Multi environment sharing
priority ：
① [ service name ]-[ Environmental Science ].yaml>[ service name ].yaml> The local environment

Thank you for your participation ：

Video address ：https://www.bilibili.com/video/BV1LQ4y127n4?p=25