Run Multiple Microservices on single Port Using Zuul

Information
As you must have seen in these blogs links Multiple Microservices with Eureka Client Configuration that how we develop microservices and register those services on eureka server and we have seen how every service run on different port Number.
Introduction
Zuul is a JVM- based router and server-side load balance form Netflix.
Zuul's rule engine provides flexibility to write rules and filters to enhance routing in a spring cloud microservices architecture.
Routing it is an integral port of a microservice architecture.
How to Include Zuul Dependency
Enbedded Zuul Reverse Proxy To enable it, annotate a spring boot man class with @EnableZuulProxy.
How to write Main Class Name is:A143mkGatewayApplication.java
package com.javatechie.spring.zulu.api; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.zuul.EnableZuulProxy; @SpringBootApplication @EnableZuulProxy @EnableDiscoveryClient public class A143mkGatewayApplication { public static void main(String[] args) { SpringApplication.run(A143mkGatewayApplication.class, args); } }
Filter Class
Base abstract class for Zuulfilters. the base class defines abstract methods to define: filterType()- to classify a filter by type. standard type in Zuul are

1. ErrorFilter
2. PostFilter
3. PreFilter
4. RouteFilter

ErrorFilter.java
package com.javatechie.spring.zulu.api.filter; import javax.servlet.http.HttpServletResponse; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; @Component public class ErrorFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(PostFilter.class); @Override public String filterType() { return "error"; } @Override public int filterOrder() { return 1; } @Override public boolean shouldFilter() { return true; } @Override public Object run() { HttpServletResponse response = RequestContext.getCurrentContext().getResponse(); log.info("ErrorFilter: " + String.format("response status is %d", response.getStatus())); return null; } }
PostFilter.java
package com.javatechie.spring.zulu.api.filter; import javax.servlet.http.HttpServletResponse; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; @Component public class PostFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(PostFilter.class); @Override public String filterType() { return "post"; } @Override public int filterOrder() { return 1; } @Override public boolean shouldFilter() { return true; } @Override public Object run() { HttpServletResponse response = RequestContext.getCurrentContext().getResponse(); log.info("PostFilter: " + String.format("response's content type is %s", response.getStatus())); return null; } }
PreFilter.java
package com.javatechie.spring.zulu.api.filter; import javax.servlet.http.HttpServletRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; @Component public class PreFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(PreFilter.class); @Override public String filterType() { return "pre"; } @Override public int filterOrder() { return 1; } @Override public boolean shouldFilter() { return true; } @Override public Object run() { RequestContext ctx = RequestContext.getCurrentContext(); HttpServletRequest request = ctx.getRequest(); log.info("PreFilter: " + String.format("%s request to %s", request.getMethod(), request.getRequestURL().toString())); return null; } }
RouteFilter.java
package com.javatechie.spring.zulu.api.filter; import javax.servlet.http.HttpServletRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; @Component public class RouteFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(RouteFilter.class); @Override public String filterType() { return "route"; } @Override public int filterOrder() { return 1; } @Override public boolean shouldFilter() { return true; } @Override public Object run() { RequestContext ctx = RequestContext.getCurrentContext(); HttpServletRequest request = ctx.getRequest(); log.info("RouteFilter: " + String.format("%s request to %s", request.getMethod(), request.getRequestURL().toString())); return null; } }
application.properties

Create pom.xml
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId> <artifactId>a143mk-gateway</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>a143mk-gateway</name> <description>API Gateway using zulu proxy</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.6.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-cloud.version>Finchley.SR1</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-zuul</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <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> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>