In a spring-cloud-netflix setup (everything uses feign,ribbon,eureka,zuul), is there any simple/elegant/out-of-the-box way (i.e. discovery based on serviceId vs URL) for CompositeAB to communicate to ServiceA and ServiceB through Zuul? In all of the examples I've seen, CompositeAB discovers and calls ServiceA directly vs. via the Zuul route for ServiceA.
Put another way, if ServiceA registers itself in Eureka as service-a, is the automatically created Zuul proxy for service-a exposed in Eureka in any discoverable way?
For real world context, this relates to network topology and firewalls (there's no direct route between CompositeAB and ServiceA - everything needs to go through the gateway). Using URLs in CompositeAB isn't awful, but seems to defeat the purpose of having the registry present (ideally, Zuul would register the proxy for service-a as something like "zuul-service-a" in the registry). That said, i do get how this particular use case doesn't really fit Zuul's purpose as an edge gateway.
Finally, i think i know how to get my desired effect through code - just wanted to check that i wasn't reinventing any wheels first.
Make sure that your Zuul proxy is registering with Eureka and fetching the registry. Any service that registers with eureka will get a route.
You don't have to allow every service that registers with eureka to be accessible via the proxy either.
A sample application.yml for your Zuul proxy that only allows service-a and service-b:
eureka:
client:
fetchRegistry: true
zuul:
add-proxy-headers: true
ignored-services: "*"
routes:
service-a:
serviceId: service-a
service-b:
serviceId: service-b
Related
I have a Spring Cloud Gateway sitting in front of other microservices. The gateway is also used as an authentication layer. I have my gateway at localhost:9000 and my microservice I would like to direct traffic to that has the predicate path (/api/scd/secure/**) on localhost:8050. I would like to prefix /ms/platform to get to the actual rest endpoint that sits in my microservice (so /ms/platform/api/scd/secure/**). The problem I have is that even if I set my uri to localhost:8050, it is using the gateway uri as the final destination (so localhost:9000/ms/platform/api/scd/secure/**)
I have tried to do lots of reading on the spring cloud gateway about how the PrefixPath filter works but everything i read suggests my configuration should work.
spring:
cloud:
gateway:
routes:
- id: scd_secure
uri: http://localhost:8500
predicates:
- Path=/api/scd/secure/**
filters:
- PrefixPath=/ms/platform
- GatewaySecurityFilter
I would expect in my GatewaySecurityFilter, the exchange.getRequest uri to be localhost:8050/ms/platform/api/scd/secure/**, but it ends up with localhost:9000/ms/platform/api/scd/secure/**
Lets consider the following situation.This example will only have urls containing localhost. I have a zuul proxy setup and lets say its running on port 8080. So
Zuul proxy-
localhost:8080
I have an eureka server setup running on port 81.
Eureka server-
localhost:8081.
I have an application lets call it by name-example which is a REST web service. Its running on 3 different ports 82,83 and 84. All 3 instances are registered with eureka server. I have a filter setup in zuul for the uri /example.
So i expect consumers to call the zuul proxy at locahost:8080/example.
Now, in the application example for the request mapping /example, there is a controller setup.
So what i want to do is basically have the consumers call localhost:8080/example and route that request to localhost:8082/example, localhost:8083/example, localhost:8084/example . I know how to load balance using ribbon and eureka and have all the appropriate properties set to achieve that.
zuul.routes.example.serviceid=example
ribbon.eureka.enabled=true.
What i want to do is have ribbon look up the list of url(s) from eureka server and then call localhost:8082/example rather localhost:8082.
Is this possible?
Thank you in advance.
You need to specify the path & serviceId
zuul:
routes:
examplepath:
path: /example/**
serviceId: name-example
stripPrefix: false
The serviceId is the name registered with Eureka. Hope you are specifying Eureka server details in you Zuul gateway.
I have a python web app, and registered with eureka using restfull api[https://github.com/Netflix/eureka/wiki/Eureka-REST-operations], and I found it status UP on the eureka web page, but my gateway server(also registered with eureka) can not find it, I call the url "gateway-server-host/myapp-url" and the following response is:
com.netflix.zuul.exception.ZuulException: Forwarding error at
org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.handleException(RibbonRoutingFilter.java:188)
at
org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.forward(RibbonRoutingFilter.java:163)
at
org.springframework.cloud.netflix.zuul.filters.route.RibbonRoutingFilter.run(RibbonRoutingFilter.java:111)
...
Caused by: com.netflix.client.ClientException: Load balancer does not
have available server for client: test at
com.netflix.loadbalancer.LoadBalancerContext.getServerFromLoadBalancer(LoadBalancerContext.java:483)
at
com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:184)
at
com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180)
any advise for this problem???
Have you looked over Spring Cloud's Sidecar ?
It basically a service over your non-jvm language service (in your case python) and with sidecar service (you have to deploy your python service and the sidecar service on the same host, if I am not mistaken) and you will include in your Zuul the endpoint to the sidecar service, which will try to handle things like eureka and such.
You spin up a new spring-boot app, with #EnableSidecar annotated, you configure the health-uri and port
example application.yml
server:
port: 5678
spring:
application:
name: sidecar
sidecar:
port: 8000
health-uri: http://localhost:8000/health.json
You can checkout Spring Cloud's documentation regarding Sidecar here for more details how to set it up
Since you are using Zuul you need to manually register routes. Its okay for them to just include the application name, from Eureka.
Example of Zuul route config:
zuul:
routes:
application1: /app1/**
application2: /app2/**
application3:
path: /app3/**
url: http://10.0.8.11:3000/
applicationN is the name registred in Eureka. The url will be resolved and load balanced automatically. For app3 the url is manually specified.
Adding Sidecar solves this problem to an extent where your Zuul /routes shows the registered Application Name.
You must have experienced , even if you do not have an actual app and just put any name with a payload following this document - [https://github.com/Netflix/eureka/wiki/Eureka-REST-operations] , that too gets registered in Eureka as an app.
I have Zuul and Eureka running, with a bunch of smaller services. Using Eureka, I can see all of the services and their associated host/IP address. Usually, I can boot up multiple instances of another service and Eureka will pick them up for Zuul to route to. I'm currently having an issue where I have three instances of a service registered in Eureka, but Zuul only routes to one of them. I don't know where to go to get diagnostic information from Zuul to understand why it isn't routing to the other two instances. I've tried simple things, like manually sending requests from the Zuul box to the service boxes to make sure they can communicate.
Does Zuul expose an endpoint to list hosts/IP addresses and their status? What are my diagnostic options?
You can try to list all your endpoints with the routes endpoint
So, if you running zuul on your localhost on port 8080 you can do a GET call to http://localhost:8080/routes and you will get something like
{
/stores/**: "http://localhost:8081"
}
Depending on the version you are using, you also need to set
management.security.enabled = false
in the application.properties
EDIT:
You can also use the logging mechanism.
Set the loglevel just of the LoadBalancerContext to debug in application.properties
#logging
logging.level.com.netflix.loadbalancer.LoadBalancerContext=DEBUG
It will log each call that is routed.
We have an infrastructure with service discovery and load balancing (i.e. server side with STM and weblogic cluster). Now we are in the process of refactoring into micro-services. We would need an API gateway which does basic routing to other microservices. Netflix Zuul looks a good candidate however I could not get Zuul working without Eureka - but we do not need Eureka since we already have service discovery and load balancing in place.
Is it possible to use Zuul without Eureka and Ribbon?
If yes please provide some guild-lines since the there's no mention about in the wiki.
Thanks.
Yes, it is totally possible.You have to use #EnableZuulProxy on your config class and config it something like this :
zuul:
routes:
yourService:
path: /yourService/**
serviceId: yourService
ribbon:
eureka:
enabled: false
yourService:
ribbon:
listOfServers: localhost:8080
A sample usage can be like this:
shared.microservice.customer.service1.url=zttp://127.0.0.1:8080/shared/microservice/customer/
shared.microservice.customer.service2.url=zttp://127.0.0.1:8181/shared/microservice/customer/
ribbon.eureka.enabled = false
zuul.routes.customer-micro-service.path: /shared/microservice/customer/**
zuul.routes.customer-micro-service.serviceId: customers
customers.ribbon.listOfServers =
zttp://ip:port1/shared/microservice/customer/,zttp://ip2:port2/shared/microservice/customer/
Yes, Of course you can. Actually, by default, if you use #EnableZuulProxy with the Spring Boot Actuator, you enable two additional endpoints:
Routes
Filters
application.yaml
zuul:
routes:
users:
path: /myusers/**
url: https://example.com/users_service
These simple url-routes do not get executed as a HystrixCommand, nor do they load-balance multiple URLs with Ribbon.
Yo can get more information from here.