SpringCloud Zuul服务网关
程序员文章站
2022-06-21 14:42:11
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前言:一个服务网关的基本要素:稳定性、高可用、性能、并发性、安全、扩展性。了解了服务网关的基本要素后,我们来看看一次HTTP请求在zuul里的生命周期是怎么样的。
1.pom文件修改:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>
2.在启动类上增加@EnableZuulProxy注解
@SpringBootApplication
@EnableZuulProxy
public class ApiGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ApiGatewayApplication.class, args);
}
}
3.在applications.yml文件里自定义配置一些路由规则:
zuul:
routes:
myProduct:
path: /myProduct/**
serviceId: product
sensitiveHeaders: #敏感头的过滤,可以查看cookie
# product: /myProduct/**
#排除某些路由
ignored-patterns:
- /**/product/listForOrder
management:
endpoints:
web:
exposure:
include: "*"
4.动态路由的实现
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
@SpringBootApplication
@EnableZuulProxy
public class ApiGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ApiGatewayApplication.class, args);
}
@ConfigurationProperties("zuul")
@RefreshScope
public ZuulProperties zuulProperties(){
return new ZuulProperties();
}
5.前置过滤器:这里以请求参数里必须带个token为例,否则没有权限访问:
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.apache.commons.lang.StringUtils;
import org.apache.http.HttpStatus;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_DECORATION_FILTER_ORDER;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
@Component
public class TokenFilter extends ZuulFilter {
@Override
public String filterType() {
return PRE_TYPE;
}
@Override
public int filterOrder() {
return PRE_DECORATION_FILTER_ORDER-1;
}
@Override
public boolean shouldFilter() {
return true;
}
@Override
public Object run() throws ZuulException {
RequestContext requestContext=RequestContext.getCurrentContext();
HttpServletRequest request=requestContext.getRequest();
//这里从url参数里获取,也可以从cookie,header里获取
String token=request.getParameter("token");
if(StringUtils.isEmpty(token)){
requestContext.setSendZuulResponse( false);
requestContext.setResponseStatusCode(HttpStatus.SC_UNAUTHORIZED);
}
return null;
}
}
6.后置过滤器:这里一向response header里添加内容为例:
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletResponse;
import java.util.UUID;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.POST_TYPE;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_RESPONSE_FILTER_ORDER;
@Component
public class addResponseHeaderFilter extends ZuulFilter {
@Override
public String filterType() {
return POST_TYPE;
}
@Override
public int filterOrder() {
return SEND_RESPONSE_FILTER_ORDER-1;
}
@Override
public boolean shouldFilter() {
return true;
}
@Override
public Object run() throws ZuulException {
RequestContext requestContext=RequestContext.getCurrentContext();
HttpServletResponse response=requestContext.getResponse();
response.setHeader("X-Foo", UUID.randomUUID().toString());
return null;
}
}
7.限流(令牌桶策略)
原理示意图:
代码样例如下:
import com.google.common.util.concurrent.RateLimiter;
import com.imooc.apigateway.exception.RateLimitException;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SERVLET_DETECTION_FILTER_ORDER;
//限流
@Component
public class RateLimitFilter extends ZuulFilter {
private static final RateLimiter RATE_LIMITER=RateLimiter.create(100);
@Override
public String filterType() {
return PRE_TYPE;
}
@Override
public int filterOrder() {
return SERVLET_DETECTION_FILTER_ORDER-1;
}
@Override
public boolean shouldFilter() {
return true;
}
@Override
public Object run() throws ZuulException {
if(!RATE_LIMITER.tryAcquire()){
throw new RateLimitException(); //自定义一个exception类
}
return null;
}
}