Amateur Grass Springcloud Tutorial | Fifth article: Routing Gateway (Zuul) (Finchley version)

In the micro-service architecture, several basic service governance components are needed, including service registration and discovery, service consumption, load balancing, circuit breakers, intelligent routing, configuration management, etc., which are co-organized by these basic components to form a simple microservices system. A brief micro-service system such as:

Note: A service and b services can be called each other, when the drawing is forgotten. And the configuration service is also registered with the service registry.

In the spring Cloud microservices system, a common load balancing method is that the client's request is first load-balanced (Zuul, Ngnix), then the service Gateway (Zuul cluster), and then to the specific services. , the service is registered to a highly available service registry cluster, all the configuration files for the service are managed by the Configuration service (the next article), the configuration files of the Config service are placed in the Git repository, so that developers can change the configuration at any time.

I. Introduction of Zuul

The main function of Zuul is routing forwarding and filtering. The routing feature is part of the microservices, such as/api/user forwarding to the User Service, and/api/shop forwarding to the shop service. The Zuul default and ribbon combine to achieve load balancing capabilities.

Zuul has the following features:

• Authentication
• Insights
• Stress Testing
• Canary Testing
• Dynamic Routing
• Service Migration
• Load Shedding
• Security
• Static Response Handling
• Active/active Traffic Management

Ii. preparatory work

Continue with the previous section of the project. In the original project, create a new project.

Iii. Creation of Service-zuul project

Its pom.xml file is as follows:

1<?xml version= "1.0" encoding= "UTF-8"?>2<project xmlns= "http://maven.apache.org/POM/4.0.0" xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"3xsi:schemalocation= "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" >4<modelVersion>4.0.0</modelVersion>5  6<groupId>com.forezp</groupId>7<artifactId>service-zuul</artifactId>8<version>0.0.1-SNAPSHOT</version>9<packaging>jar</packaging>Ten   One<name>service-zuul</name> A<description>demo Project forSpring boot</description> -   -<parent> the<groupId>com.forezp</groupId> -<artifactId>sc-f-chapter5</artifactId> -<version>0.0.1-SNAPSHOT</version> -</parent> +   -<dependencies> +<dependency> A<groupId>org.springframework.cloud</groupId> at<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> -</dependency> -<dependency> -<groupId>org.springframework.boot</groupId> -<artifactId>spring-boot-starter-web</artifactId> -</dependency> in<dependency> -<groupId>org.springframework.cloud</groupId> to<artifactId>spring-cloud-starter-netflix-zuul</artifactId> +</dependency> -</dependencies> the</project>

In its entry Applicaton class plus annotation @enablezuulproxy, the function of Zuul is turned on:

1 @SpringBootApplication2 @EnableZuulProxy3 @EnableEurekaClient4 @EnableDiscoveryClient5  Public classservicezuulapplication {6  7      Public Static voidMain (string[] args) {8Springapplication.run (servicezuulapplication.class, args);9     }Ten}

Add the configuration file application.yml with the following configuration code:

1 Eureka:2 Client:3 serviceurl:4Defaultzone:http://localhost:8761/eureka/5 Server:6port:87697 Spring:8 Application:9name:service-ZuulTen Zuul: One routes: Aapi-A: -Path:/api-a/** - Serviceid:service-ribbon the Api-b: - Path:/api-b/** - serviceid:service-feign

First specify that the service registry address is http://localhost:8761/eureka/, the service port is 8769, the service name is Service-zuul, and the requests beginning with/api-a/are forwarded to the Service-ribbon service; api-b/the beginning of the request is forwarded to the Service-feign service;

Run these five projects sequentially; Open browser access: HTTP://LOCALHOST:8769/API-A/HI?NAME=FOREZP; Browser display:

Hi forezp,i am from port:8762

Open browser access: HTTP://LOCALHOST:8769/API-B/HI?NAME=FOREZP; Browser display:

Hi forezp,i am from port:8762

This means that Zuul is acting as a route.

Iv. Service Filtering

Zuul is not only a route, but also a filter to do some security verification. Continue to reform the project;

1 @Component2  Public classMyfilterextendsZuulfilter {3  4     Private StaticLogger log = Loggerfactory.getlogger (myfilter.class);5 @Override6      PublicString FilterType () {7         return"Pre";8     }9  Ten @Override One      Public intFilterorder () { A         return0; -     } -   the @Override -      Public BooleanShouldfilter () { -         return true; -     } +   - @Override +      PublicObject Run () { ARequestContext CTX =Requestcontext.getcurrentcontext (); atHttpServletRequest request =ctx.getrequest (); -Log.info (String.Format ("%s >>>%s", Request.getmethod (), Request.getrequesturl (). toString ( )); -Object Accesstoken = Request.getparameter ("token"); -         if(Accesstoken = =NULL) { -Log.warn ("token is empty"); -Ctx.setsendzuulresponse (false); inCtx.setresponsestatuscode (401); -             Try { toCtx.getresponse (). Getwriter (). Write ("token is empty"); +}Catch(Exception e) {} -   the             return NULL; *         } $Log.info ("OK");Panax Notoginseng         return NULL; -     } the}

• FilterType: Returns a String representing the type of filter, and defines the filter type for four different lifecycles in Zuul, as follows:
  • Pre: Before routing
  • Routing: The time of routing
  • Post: After routing
  • Error: Sending the wrong call
  • Filterorder: The Order of filtering
  • Shouldfilter: Here can write logical judgments, whether to filter, this article true, filter forever.
  • Run: The specific logic of the filter. Can be complicated, including checking sql,nosql to see if the request has access.

At this time visit: HTTP://LOCALHOST:8769/API-A/HI?NAME=FOREZP; page display:

Token is empty

Access to http://localhost:8769/api-a/hi?name=forezp&token=22;
Page display:

Hi forezp,i am from port:8762

This article source code download:
Https://github.com/forezp/SpringCloudLearning/tree/master/sc-f-chapter5

V. References:

Http://cloud.spring.io/spring-cloud-static/Finchley.RELEASE/single/spring-cloud.html

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Amateur Grass Springcloud Tutorial | Fifth article: Routing Gateway (Zuul) (Finchley version)