Gateway-88

Dynamic up and down line ： To send a request, you need to know the address of the goods and services , If the product server has 1,2,3 Number server ,1 Number After dropping the line , It has to be changed , So we need to Gateway dynamically manages , He can sense whether a service is online or offline in real time from the registry . The gateway can always help us route requests to the specified location correctly 【 Go through the gateway first , The gateway routes to the service provider 】

The second demand ： authentication 、 monitor ; If every service does , There will be a lot of repeated development

The client requests the gateway first , And then the gateway transfers it to other services

Performance comparison

Intercept ： The request should also be added with query permission , See if the user has access to the request , You also need gateways .

So we use spring cloud Of gateway Components do gateway functions .

The gateway is the gateway to request traffic , Common functions include Routing and forwarding , Permission to check , Current limiting control etc. .springcloud gateway To replace the zuul gateway .

https://spring.io/projects/spring-cloud-gateway

Reference manual ：https://cloud.spring.io/spring-cloud-gateway/2.2.x/reference/html/

Three core concepts ：

• Route: The basic building block of the gateway. It is defined by an ID, a destination URI, a collection of predicates Assertion , and a collection of filters. A route is matched if the aggregate predicate is true. Send a request to the gateway , The gateway routes the request to the specified service . Routing has id, Destination uri, A collection of assertions , Match the assertion to reach the specified location ,（ The route has an identifier id, Between routes by id To distinguish between . A collection of assertions ：, A collection of filters ：, As long as the route matches the assertion , The assertion is true , The route matches , Can reach the designated position , Request for issue API gateway , Whether to route to one place or not , We have to have a conditional judgment , This conditional judgment is assertion ）

• Predicate Assertion : This is a Java 8 Function Predicate. The input type is a Spring Framework ServerWebExchange. This lets you match on anything from the HTTP request, such as headers or parameters. Namely java8 Assertion function in , Match any information in the current request , Including requesting first class . Which service is routed according to the request header

• Filter: These are instances of Spring Framework GatewayFilter that have been constructed with a specific factory. Here, you can modify requests and responses before or after sending the downstream request. Filter requests and responses can be modified .

The client sends the request to the server . There is a gateway in the middle . Give it to the mapper first , If you can handle it, give it to handler Handle , Then give it to a series of filer, Then give it to the specified service , Then return to the client .

To sum up ： Request arrival gateway , Gateway assertion , Whether the request conforms to a The rules , If meet , Just follow this routing rule , Route to the specified place , The journey to the designated place requires a series of Filter . All the difficulties ： How do we define routing rules , How do assertions determine success or failure , How to configure , What to use filter I have to be clear in my heart

The function of assertion ： Satisfy the assertion condition 3, Just assign to the route 2

There are many assertions .

spring:
  cloud:
    gateway:
      routes:
      - id: after_route
        uri: https://example.org
        predicates:
        - Cookie=mycookie,mycookievalue

- Representative array , You can set Cookie The content such as . Only the assertion succeeds , To the specified address .

spring:
  cloud:
    gateway:
      routes:
      - id: after_route
        uri: https://example.org
        predicates:
        - name: Cookie
          args:
            name: mycookie
            regexp: mycookievalue

Create microservices , Use initilizer,Group：com.atguigu.gulimall,Artifact： gulimall-gateway,package：com.atguigu.gulimall.gateway. Search for gateway Choose .

pom.xml Riga common rely on , modify jdk edition ,

stay gateway Start the registration service discovery in the service @EnableDiscoveryClient, To configure nacos Address of Registration Center applicaion.properties. such gateway Also registered to nacos in , Other services can be found nacos, The gateway can also pass through nacos Find other services

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
spring.application.name=gulimall-gateway
server.port=88

bootstrap.properties Fill in nacos Configure center address

spring.application.name=gulimall-gateway

spring.cloud.nacos.config.server-addr=127.0.0.1:8848
spring.cloud.nacos.config.namespace=bfa85f10-1a9a-460c-a7dc-efa961b45cc1

This project is in nacos Service name in

spring:
    application:
        name: gulimall-gateway

Go again nacos Create a namespace in gateway（ Projects are separated from projects by namespaces ）, Then create a file in the namespace guilmall-gateway.yml

Create... In the project application.yml, Forward to uri etc.

spring:
  cloud:
    gateway:
      routes:
        - id: test_route
          uri: https://www.baidu.com
          predicates:
            - Query=url,baidu

        - id: qq_route
          uri: https://www.qq.com
          predicates:
            - Query=url,qq

        - id: product_route
          uri: lb://gulimall-product
          predicates:
            - Path=/api/product/**
          filters:
            - RewritePath=/api/(?<segment>.*),/$\{
    segment}

        - id: third_party_route
          uri: lb://gulimall-third-party
          predicates:
            - Path=/api/thirdparty/**
          filters:
            - RewritePath=/api/thirdparty/(?<segment>.*),/$\{
    segment}

        - id: member_route
          uri: lb://gulimall-member
          predicates:
            - Path=/api/member/**
          filters:
            - RewritePath=/api/(?<segment>.*),/$\{
    segment}

        - id: ware_route
          uri: lb://gulimall-ware
          predicates:
            - Path=/api/ware/**
          filters:
            - RewritePath=/api/(?<segment>.*),/$\{
    segment}

        - id: admin_route
          uri: lb://renren-fast
          predicates:
            - Path=/api/**
          filters:  #  This filter is related to the verification code ,api Content Cache /renren-fast, And pay attention to /renren-fast Also registered to nacos in 
            - RewritePath=/api/(?<segment>.*),/renren-fast/$\{
    segment}



##  The front-end project ,/api Prefix . First come to the gateway and then assert to match , Filter modification url, Like jump to renren Microservices , So pay attention to renren Back end projects are also registered to  nacos in 
## http://localhost:88/api/captcha.jpg http://localhost:8080/renren-fast/captcha.jpg
## http://localhost:88/api/product/category/list/tree http://localhost:10000/product/category/list/tree

test localhost:8080/hello?url=baidu

The gateway uses Netty,Netty Than Tomcat High performance

2021-12-31 16:20:37.276  INFO 19364 --- [           main] o.s.b.web.embedded.netty.NettyWebServer  : Netty started on port(s): 88

 predicates:
            - Query=url(key),baidu(value)