diff --git a/spring-cloud.html b/spring-cloud.html index 5b0d66d..f25f031 100644 --- a/spring-cloud.html +++ b/spring-cloud.html @@ -2066,24 +2066,84 @@ public class Application extends FeignConfigurer {

Embedded Zuul Reverse Proxy

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Spring Cloud has created an embedded Zuul proxy to ease the development of a very common use case where a UI application wants to proxy calls to one or more back end services. To enable it, annotate a Spring Boot main class with @EnableZuulProxy. This forwards local calls to the appropriate service. By convention, a service with the spring.application.name of users, will receive requests from the proxy located at /users. The proxy uses Ribbon to locate an instance to forward to via Eureka. To skip having a service automatically added from eureka, set zuul.ignored-services = service1. Forwarding to the service is protected by a Hystrix circuit breaker. Additional rules can be configured via the Spring environment. The Config Server is an ideal place for the Zuul configuration. Zuul Embedded Proxy configuration rules look like the following:

+

Spring Cloud has created an embedded Zuul proxy to ease the development of a very common use case where a UI application wants to proxy calls to one or more back end services. To enable it, annotate a Spring Boot main class with @EnableZuulProxy, and this forwards local calls to the appropriate service. By convention, a service with the Eureka ID "users", will receive requests from the proxy located at /users. The proxy uses Ribbon to locate an instance to forward to via Eureka. To skip having a service automatically added from eureka, set zuul.ignored-services = service1.

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+
+

To augment or change the proxy routes, you can add external +configuration like the following:

+
+
+
application.yml
-
zuul.route.users: /myusers/**
+
 zuul:
+  routes:
+    users: /myusers/**
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This means that http calls to /myusers get forwarded to the users service. This proxy configuration is useful for services that host a user interface to proxy to the backend services it requires. To add a prefix to the mapping, set zuul.proxy.mapping to a value, such as /api. To strip the proxy mapping from the request before forwarding set zuul.proxy.strip-mapping = true.

+

This means that http calls to "/myusers" get forwarded to the "users" +service. This configuration is useful for a user interface to proxy to +the backend services it requires (avoiding the need to manage CORS and +authentication concerns independently for all the backends).

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The Zuul proxy supports Ant-style patterns.

+

To get more fine-grained control over a route you can specify the path +and the serviceId independently:

+
+
+
application.yml
+
+
 zuul:
+  routes:
+    users:
+      path: /myusers/**
+      serviceId: users_service
+
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The X-Forwarded-Host header added to the forwarded requests by default. To turn it off set zuul.proxy.add-proxy-headers = false.

+

This means that http calls to "/myusers" get forwarded to the +"users_service" service. The route has to have a "path" which can be +specified as an ant-style pattern, so "/myusers/" only matches one +level, but "/myusers/*" matches hierarchically.

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An application with the @EnableZuulProxy could act as a standalone server if you set a default route, for example zuul.route.home: / would route / to the home service.

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The location of the backend can be specified as either a "serviceId" +(for a Eureka service) or a "url" (for a physical location), e.g.

+
+
+
application.yml
+
+
 zuul:
+  routes:
+    users:
+      path: /myusers/**
+      url: http://example.com/users_service
+
+
+
+

Forwarding to the service is protected by a Hystrix circuit breaker so if a service is down the client will see an error, but once the circuit is open the proxy will not try to contact the service.

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+
+

To add a prefix to all mappings, set zuul.prefix to a value, such as /api. To strip the proxy prefix from the request before the request is forwarded set zuul.stripPrefix = true. You can also strip the non-wildcard prefix from individual routes, e.g.

+
+
+
application.yml
+
+
 zuul:
+  routes:
+    users:
+      path: /myusers/**
+      stripPrefix: true
+
+
+
+

In this example requests to "/myusers/101" will be forwarded to "/101" on the "users" service (the path is stripped up to the first wildcard character).

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+
+

The X-Forwarded-Host header added to the forwarded requests by default. To turn it off set zuul.addProxyHeaders = false.

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+
+

An application with the @EnableZuulProxy could act as a standalone server if you set a default route ("/"), for example zuul.route.home: / would route all traffic (i.e. "/**") to the "home" service.

@@ -2628,7 +2688,7 @@ service or the "resource" service if you have one).