SpringCloud+Nacos+Gateway

- SpringBoot integrates Gateway+Nacos

SpringBoot integrates Gateway+Nacos

This article only demonstrates access to other services through the gateway service, and does not demonstrate other functions of the gateway

1. Environment preparation

1. Version environment

Jdk: <java.version>1.8</java.version>
SpringBoot: <version>2.4.2</version>
SpringCloud: <spring.cloud.version>2020.0.1</spring.cloud.version>
SpringCloudAlibaba: <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>

The following is the pom configuration in the project, which can be used directly

1. Independent order/user service pom file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.scg</groupId>
    <artifactId>spring-cloud-order-center</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-cloud-order-center</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring.cloud.version>2020.0.1</spring.cloud.version>
        <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2. Independent gateway service pom file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.scg</groupId>
    <artifactId>spring-cloud-nacos</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-cloud-gateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring.cloud.version>2020.0.1</spring.cloud.version>
        <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <!--得不加上这个配置，不然会报503-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2. Service environment

This section uses a simple case to demonstrate the use of Spring Cloud Gateway. First, we prepare three SpringBoo applications:

spring-cloud-user-center : stand-alone user service
spring-cloud-order-center : Standalone order service
spring-cloud-gateway : an independent gateway service

2. Actual combat

1. Create User Service

Introduce related dependencies

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

yml configuration

server:
  port: 8085

spring:
  application:
    name: spring-cloud-user-center
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        ip: 127.0.0.1
management:
  endpoints:
    web:
      exposure:
        include: "*"

write test class

/**
 * @author gf
 * @date 2023/2/14
 */
@Slf4j
@RestController
public class UserController {
    
    
    @RequestMapping("/user")
    public String user(){
    
    
        log.info("hello Mr gateway,this is user serve");
        return "hello Mr gateway,this is user serve";
    }
}

Since we want to register the service to the registry, we need to add the @EnableDiscoveryClient annotation to the startup class after introducing the nacos dependency

@EnableDiscoveryClient
@SpringBootApplication
public class SpringCloudUserCenterApplication {
    
    

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

}

2. Create order service

The process of creating an order service is the same as that of creating a user service. We can make some changes in the test class to distinguish the test
class that calls the order service later.

@Slf4j
@RestController
public class OrderController {
    
    
    @RequestMapping("/order")
    public String getOrder(){
    
    
        log.info("hello Mr gateway,this is order serve");
        return "hello Mr gateway,this is order serve";
    }
}

3. Create a gateway service

Introduce related dependencies

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.scg</groupId>
    <artifactId>spring-cloud-nacos</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-cloud-gateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <spring.cloud.version>2020.0.1</spring.cloud.version>
        <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <!--得不加上这个配置，不然会报503-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

Configure the yml file

server:
  port: 8082
spring:
  application:
    name: gateway_server
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    gateway:
      discovery:
        locator:
          #开启从注册中心动态创建路由的功能，利用微服务名进行路由
          enabled: true
          #开启小写验证，默认feign根据服务名查找都是用的全大写
          lowerCaseServiceId: true
      routes:
        - id: spring-cloud-order-center
          uri: lb://spring-cloud-order-center
          # 断言,路径相匹配的进行路由
          predicates:
            - Path=/order-center/**
          filters:
            - StripPrefix=1

        - id: spring-cloud-user-center
          uri: lb://spring-cloud-user-center
          # 断言,路径相匹配的进行路由
          predicates:
            - Path=/user-center/**
          filters:
            - StripPrefix=1
management:
  endpoints:
    web:
      exposure:
        include: "*"


`3. 启动类添加@EnableDiscoveryClient注解

```java
@EnableDiscoveryClient
@SpringBootApplication
public class SpringCloudGatewayApplication {
    
    

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

}

4. Test

Start three services at the same time, we can see that the three services have been registered in the nacos registration center

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According to our configuration, visiting http://localhost:8082/user-center/user will call the user interface of the user center, visiting http://localhost:8082/order-center/order will call the order interface of the order center, Next we test

Access user services through the gateway
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Access order service through gateway
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3. Pit avoidance guide

Question 1 – Question 503

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Solution: Add the following dependencies

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

Cause of the problem:
Reference: gateway 503 problem

Question 2 – The gateway service starts to report an error

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of method modifyRequestBodyGatewayFilterFactory in org.springframework.cloud.gateway.config.GatewayAutoConfiguration required a bean of type 'org.springframework.http.codec.ServerCodecConfigurer' that could not be found.


Action:

Consider defining a bean of type 'org.springframework.http.codec.ServerCodecConfigurer' in your configuration.


Process finished with exit code 1

problem causes:

This is due to the dependencies of spring-boot-starter-web in the dependent modules, and Spring Cloud Gateway does not yet support spring-boot-starter-web

solution:

Gateway service removes spring-boot-starter-web dependency

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