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Nacos Configuration Center
Build a Nacos cluster

Nacos Configuration Center

Nacos configuration management
In addition to being a registration center, Nacos can also be used for configuration management.

Unified configuration management

When more and more instances of microservices are deployed, reaching tens or hundreds, modifying the configuration of microservices one by one will be frustrating and error-prone. We need a unified configuration management solution that can centrally manage the configuration of all instances.

On the one hand, Nacos can centrally manage configurations, and on the other hand, it can promptly notify microservices when configuration changes to achieve hot updates of configurations.

Add configuration files in nacos

How to manage configuration in nacos?

Then fill in the configuration information in the pop-up form:

Note: The core configuration of the project needs to be hot-updated before it is necessary to put it into nacos management. Some configurations that rarely change are better stored locally in the microservice.

Pull configuration from microservice

The microservice must pull the configuration managed in nacos and merge it with the local application.yml configuration to complete the project startup.

But if application.yml has not been read, how to know the nacos address?

Therefore, spring introduces a new configuration file: the bootstrap.yaml file, which will be read before application.yml. The process is as follows:

insert image description here

1) Introduce nacos-config dependency

First, in the user-service service, introduce the client dependency of nacos-config:

<!--nacos配置管理依赖-->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

2) Add bootstrap.yaml

Then, add a bootstrap.yaml file in user-service with the following content:

spring:
  application:
    name: userservice # 服务名称
  profiles:
    active: dev #开发环境，这里是dev 
  cloud:
    nacos:
      server-addr: localhost:8848 # Nacos地址
      config:
        file-extension: yaml # 文件后缀名

Here, the nacos address will be obtained based on spring.cloud.nacos.server-addr, and then based on

spring.application.name−{spring.profiles.active}.${spring.cloud.nacos.config.file-extension} is used as the file id to read the configuration.
In this example, it is to read userservice-dev.yaml

Configure Hot Update

Our ultimate goal is to modify the configuration in nacos so that the configuration can take effect in the microservice without restarting, that is, configuration hot update.

After the configuration file is changed in Nacos, the microservice can be detected without restarting. However, you need to implement the following two configurations:

Method 1 : Add annotations to the class where the variable injected by @Value is located@RefreshScope

@Slf4j
@RestController
@RequestMapping("/user")
@RefreshScope
public class UserController {
    
    
    // 注入nacos中的配置属性
    @Value("${pattern.dateformat}")
    private String dateformat;

    // 编写controller，通过日期格式化器来格式化现在时间并返回
    @GetMapping("now")
    public String now() {
    
    
        return LocalDateTime.now().format(
                DateTimeFormatter.ofPattern(dateformat)
        );
    }
}

Method 2 : Use @ConfigurationProperties to automatically inject

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


@Slf4j
@RestController
@RequestMapping("/user")
public class UserController {
    
    
    @Autowired
    private PatternProperties properties;

    // 编写controller，通过日期格式化器来格式化现在时间并返回
    @GetMapping("now")
    public String now() {
    
    
        return LocalDateTime.now().format(
                DateTimeFormatter.ofPattern(properties.getDateformat())
        );
    }

}

Summarize:

After the Nacos configuration is changed, the microservices can be hot updated in the following ways:

Inject through @Value annotation and refresh with @RefreshScope
Injected through @ConfigurationProperties, automatically refreshed

Precautions:

Not all configurations are suitable to be placed in the configuration center, and maintenance is more troublesome.
It is recommended to put some key parameters that need to be adjusted at runtime into the nacos configuration center, which are generally custom configurations.

Shared configuration across multiple environments

Multiple environments refer to spring.profiles.active

Such as dev development environment, test test environment

When the microservice starts, multiple configuration files will be read from nacos:

[spring.application.name]-[spring.profiles.active].yaml，例如：userservice-dev.yaml、userservice-test.yaml
[spring.application.name].yaml，例如：userservice.yaml

No matter how the profile changes, the [spring.application.name].yaml file (userservice.yaml) will definitely be loaded, so the multi-environment sharing configuration can be written to this file

Priority of various configurations:

Summary :

The configuration file that the microservice will read from nacos:

[Service name]-[spring.profile.active].yaml, environment configuration
[Service name].yaml, default configuration, shared in multiple environments

priority:

[Service name]-[Environment].yaml >[Service name].yaml > Local configuration

Build a Nacos cluster

Nacos production environment must be deployed in cluster state:

The addresses of the three nacos nodes:

node	ip	port
nacos1	127.0.0.1	8845
nacos2	127.0.0.1	8846
nacos3	1270.0.1	8847

Build a cluster

Basic steps to build a cluster:

Build the database and initialize the database table structure
Download nacos installation package
Configure nacos
Start nacos cluster
nginx reverse proxy

Initialize the database

Nacos default data is stored in the embedded database Derby, which is not a production-available database.

The officially recommended best practice is to use a high-availability database cluster with master-slave.

Here we take a single-point database as an example to explain.

First create a new database, name it nacos, and then import the following SQL:

CREATE TABLE `config_info` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `data_id` varchar(255) NOT NULL COMMENT 'data_id',
  `group_id` varchar(255) DEFAULT NULL,
  `content` longtext NOT NULL COMMENT 'content',
  `md5` varchar(32) DEFAULT NULL COMMENT 'md5',
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '修改时间',
  `src_user` text COMMENT 'source user',
  `src_ip` varchar(50) DEFAULT NULL COMMENT 'source ip',
  `app_name` varchar(128) DEFAULT NULL,
  `tenant_id` varchar(128) DEFAULT '' COMMENT '租户字段',
  `c_desc` varchar(256) DEFAULT NULL,
  `c_use` varchar(64) DEFAULT NULL,
  `effect` varchar(64) DEFAULT NULL,
  `type` varchar(64) DEFAULT NULL,
  `c_schema` text,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_configinfo_datagrouptenant` (`data_id`,`group_id`,`tenant_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='config_info';

/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = config_info_aggr   */
/******************************************/
CREATE TABLE `config_info_aggr` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `data_id` varchar(255) NOT NULL COMMENT 'data_id',
  `group_id` varchar(255) NOT NULL COMMENT 'group_id',
  `datum_id` varchar(255) NOT NULL COMMENT 'datum_id',
  `content` longtext NOT NULL COMMENT '内容',
  `gmt_modified` datetime NOT NULL COMMENT '修改时间',
  `app_name` varchar(128) DEFAULT NULL,
  `tenant_id` varchar(128) DEFAULT '' COMMENT '租户字段',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_configinfoaggr_datagrouptenantdatum` (`data_id`,`group_id`,`tenant_id`,`datum_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='增加租户字段';


/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = config_info_beta   */
/******************************************/
CREATE TABLE `config_info_beta` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `data_id` varchar(255) NOT NULL COMMENT 'data_id',
  `group_id` varchar(128) NOT NULL COMMENT 'group_id',
  `app_name` varchar(128) DEFAULT NULL COMMENT 'app_name',
  `content` longtext NOT NULL COMMENT 'content',
  `beta_ips` varchar(1024) DEFAULT NULL COMMENT 'betaIps',
  `md5` varchar(32) DEFAULT NULL COMMENT 'md5',
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '修改时间',
  `src_user` text COMMENT 'source user',
  `src_ip` varchar(50) DEFAULT NULL COMMENT 'source ip',
  `tenant_id` varchar(128) DEFAULT '' COMMENT '租户字段',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_configinfobeta_datagrouptenant` (`data_id`,`group_id`,`tenant_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='config_info_beta';

/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = config_info_tag   */
/******************************************/
CREATE TABLE `config_info_tag` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `data_id` varchar(255) NOT NULL COMMENT 'data_id',
  `group_id` varchar(128) NOT NULL COMMENT 'group_id',
  `tenant_id` varchar(128) DEFAULT '' COMMENT 'tenant_id',
  `tag_id` varchar(128) NOT NULL COMMENT 'tag_id',
  `app_name` varchar(128) DEFAULT NULL COMMENT 'app_name',
  `content` longtext NOT NULL COMMENT 'content',
  `md5` varchar(32) DEFAULT NULL COMMENT 'md5',
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '修改时间',
  `src_user` text COMMENT 'source user',
  `src_ip` varchar(50) DEFAULT NULL COMMENT 'source ip',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_configinfotag_datagrouptenanttag` (`data_id`,`group_id`,`tenant_id`,`tag_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='config_info_tag';

/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = config_tags_relation   */
/******************************************/
CREATE TABLE `config_tags_relation` (
  `id` bigint(20) NOT NULL COMMENT 'id',
  `tag_name` varchar(128) NOT NULL COMMENT 'tag_name',
  `tag_type` varchar(64) DEFAULT NULL COMMENT 'tag_type',
  `data_id` varchar(255) NOT NULL COMMENT 'data_id',
  `group_id` varchar(128) NOT NULL COMMENT 'group_id',
  `tenant_id` varchar(128) DEFAULT '' COMMENT 'tenant_id',
  `nid` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`nid`),
  UNIQUE KEY `uk_configtagrelation_configidtag` (`id`,`tag_name`,`tag_type`),
  KEY `idx_tenant_id` (`tenant_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='config_tag_relation';

/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = group_capacity   */
/******************************************/
CREATE TABLE `group_capacity` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `group_id` varchar(128) NOT NULL DEFAULT '' COMMENT 'Group ID，空字符表示整个集群',
  `quota` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '配额，0表示使用默认值',
  `usage` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '使用量',
  `max_size` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '单个配置大小上限，单位为字节，0表示使用默认值',
  `max_aggr_count` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '聚合子配置最大个数，，0表示使用默认值',
  `max_aggr_size` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '单个聚合数据的子配置大小上限，单位为字节，0表示使用默认值',
  `max_history_count` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '最大变更历史数量',
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '修改时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_group_id` (`group_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='集群、各Group容量信息表';

/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = his_config_info   */
/******************************************/
CREATE TABLE `his_config_info` (
  `id` bigint(64) unsigned NOT NULL,
  `nid` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `data_id` varchar(255) NOT NULL,
  `group_id` varchar(128) NOT NULL,
  `app_name` varchar(128) DEFAULT NULL COMMENT 'app_name',
  `content` longtext NOT NULL,
  `md5` varchar(32) DEFAULT NULL,
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `src_user` text,
  `src_ip` varchar(50) DEFAULT NULL,
  `op_type` char(10) DEFAULT NULL,
  `tenant_id` varchar(128) DEFAULT '' COMMENT '租户字段',
  PRIMARY KEY (`nid`),
  KEY `idx_gmt_create` (`gmt_create`),
  KEY `idx_gmt_modified` (`gmt_modified`),
  KEY `idx_did` (`data_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='多租户改造';


/******************************************/
/*   数据库全名 = nacos_config   */
/*   表名称 = tenant_capacity   */
/******************************************/
CREATE TABLE `tenant_capacity` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `tenant_id` varchar(128) NOT NULL DEFAULT '' COMMENT 'Tenant ID',
  `quota` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '配额，0表示使用默认值',
  `usage` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '使用量',
  `max_size` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '单个配置大小上限，单位为字节，0表示使用默认值',
  `max_aggr_count` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '聚合子配置最大个数',
  `max_aggr_size` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '单个聚合数据的子配置大小上限，单位为字节，0表示使用默认值',
  `max_history_count` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '最大变更历史数量',
  `gmt_create` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
  `gmt_modified` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '修改时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_tenant_id` (`tenant_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='租户容量信息表';


CREATE TABLE `tenant_info` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `kp` varchar(128) NOT NULL COMMENT 'kp',
  `tenant_id` varchar(128) default '' COMMENT 'tenant_id',
  `tenant_name` varchar(128) default '' COMMENT 'tenant_name',
  `tenant_desc` varchar(256) DEFAULT NULL COMMENT 'tenant_desc',
  `create_source` varchar(32) DEFAULT NULL COMMENT 'create_source',
  `gmt_create` bigint(20) NOT NULL COMMENT '创建时间',
  `gmt_modified` bigint(20) NOT NULL COMMENT '修改时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_tenant_info_kptenantid` (`kp`,`tenant_id`),
  KEY `idx_tenant_id` (`tenant_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='tenant_info';

CREATE TABLE `users` (
	`username` varchar(50) NOT NULL PRIMARY KEY,
	`password` varchar(500) NOT NULL,
	`enabled` boolean NOT NULL
);

CREATE TABLE `roles` (
	`username` varchar(50) NOT NULL,
	`role` varchar(50) NOT NULL,
	UNIQUE INDEX `idx_user_role` (`username` ASC, `role` ASC) USING BTREE
);

CREATE TABLE `permissions` (
    `role` varchar(50) NOT NULL,
    `resource` varchar(255) NOT NULL,
    `action` varchar(8) NOT NULL,
    UNIQUE INDEX `uk_role_permission` (`role`,`resource`,`action`) USING BTREE
);

INSERT INTO users (username, password, enabled) VALUES ('nacos', '$2a$10$EuWPZHzz32dJN7jexM34MOeYirDdFAZm2kuWj7VEOJhhZkDrxfvUu', TRUE);

INSERT INTO roles (username, role) VALUES ('nacos', 'ROLE_ADMIN');

Download nacos
nacos has a download address on GitHub: https://github.com/alibaba/nacos/tags. You can choose any version to download.

Only version 1.4.1 is used in this example:

Configure Nacos

Unzip this package to any non-Chinese directory

Directory description:

bin: startup script
conf: configuration file
Enter the conf directory of nacos, modify the configuration file cluster.conf.example, and rename it to cluster.conf:

Then add content:

127.0.0.1:8845
127.0.0.1.8846
127.0.0.1.8847

Then modify the application.properties file and add database configuration

spring.datasource.platform=mysql

db.num=1

db.url.0=jdbc:mysql://127.0.0.1:3306/nacos?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC
db.user.0=root
db.password.0=123

start up

Copy the nacos folder into three copies and name them respectively: nacos1, nacos2, nacos3

Then modify the application.properties in the three folders respectively,

nacos1:

server.port=8845

nacos2:

server.port=8846

nacos3:

server.port=8847

Then start three nacos nodes respectively:

startup.cmd

nginx reverse proxy

Download the nginx installation package:

Unzip to any non-Chinese directory:

Modify the conf/nginx.conf file, the configuration is as follows

upstream nacos-cluster {
    server 127.0.0.1:8845;
	server 127.0.0.1:8846;
	server 127.0.0.1:8847;
}

server {
    listen       80;
    server_name  localhost;

    location /nacos {
        proxy_pass http://nacos-cluster;
    }
}

Then visit: http://localhost/nacos in the browser.

The application.yml file configuration in the code is as follows:

spring:
  cloud:
    nacos:
      server-addr: localhost:80 # Nacos地址

In actual deployment, you need to set a domain name for the nginx server that acts as a reverse proxy, so that if there is a server to migrate to the Nacos client later, there is no need to change the configuration. Each node of
Nacos should be deployed to multiple different servers for disaster recovery and isolation

Chapter 3 Microservice Configuration Center