I have two machines (with same application) register to eureka server.
all requests to these services are through zuul proxy.
my application.properties of my backend services is:
spring.application.name=core
my application.properties of my zuul proxy is:
zuul.sensitiveHeaders=Set-Cookie
zuul.routes.address.path=/to-address/**
zuul.routes.address.url=http://localhost:8888
zuul.routes.service.path=/by-service/**
zuul.routes.service.url=CORE
I have two questions:
All three request below are working, which one should I use?
What is the difference with upper case and lower case?
http://localhost:9090/api/by-service/customer/1
http://localhost:9090/api/core/customer/1
http://localhost:9090/api/CORE/customer/1
When I call the service in the following way:
http://localhost:9090/api/to-address/customer/1
I noticed that a new session is being created by my core server, which force my user to login again. Any idea why?
As you can see it's the same method (same filter, same application...) with just a routing difference.
you need to use req.getRequestedSessionId() instead of req.getSession().getId().
Related
I am following a course about microservice architecture using spring, covering netflix's eureka.
The clientui serves webpages and calls the 3 microservices when needed.
The config-server serves configuration for the 3 microservices from a git repo.
Of course the 3 microservices are registered as eureka clients.
My questions are :
should the config server and also be registered as an eureka client, or is there no benefit in doing so?
what about the clientui (which is the web entry point) ? can it be registered as an eureka client in order to benefit from load balancing system and if yes, how then should the app be accessed by clients?
About your first question :- Yes you can register config server as eureka client. Benefit of this will be that in terms of service management it will give you a single point of visibility of all the services. Also later if you try to expand your app in terms of distributed architecture and say you implement an api gateway like zuul, it will be easy for you to setup a fallback config server say if one config server goes down requests can be routed to other config server and so on.
About your second question :- Honestly speaking , I didn't understand it very well in first place. I have never seen any ui service registering to eureka so I am not very sure about this. Still if you have more doubts about it , you can let me know like is it a angular ui or is it a http based client or what.
I have setup multiple instances of my microservice and registered to my eureka server. It uses ribbon for client side load balancing and uses zuul as gateway server. All usual stuff. I would like to capture the logs of which instance of my service is responding for each request. So that I can able to bring some conclusion based on my usage of each instances. How to do that?
You can try to set the loglevel just of the LoadBalancerContext to debug in application.properties
#logging
logging.level.com.netflix.loadbalancer.LoadBalancerContext=DEBUG
I have a simple Zuul app that has a single route in the application.yml to route to my microservice. It's working.
However, what I'm looking for is a more dynamic solution where I can wire up routes dynamically, either through code or perhaps by POSTing to some Zuul endpoints during a build (possibly by using springfox and a swagger definition from microservices). I could not find an API for Zuul.
I'm somewhat aware of Eureka and that seems like a solution to abstract away the routing by doing discovery. However, I'm curious if there's a solution without introducing Eureka. If there's a way to wire up these routes in Zuul during a build vs. having to edit the application.yml every time.
Thanks in advance.
If you go for Eureka this will actually work ootb. Zuul as packaged in spring cloud will automatically expose every service using its name. So if you register a service called users in Eureka, Zuul will automatically create a route /users forwarding to the instances by default. That will only allow simple url structures but should solve your problem.
Please see the official documentation for details:
By convention, a service with the ID "users", will receive requests from the proxy located at /users (with the prefix stripped). The proxy uses Ribbon to locate an instance to forward to via discovery, and all requests are executed in a hystrix command, …
I'm actually editing a blog post about this exact topic (Routing and Filtering using Spring Cloud Zuul Server) but the source code has been available and working for some time now. Feel free to use it as a reference:
https://bitbucket.org/asimio/zuulserver
https://bitbucket.org/asimio/discoveryserver (in case routes are configured with serviceIds)
https://bitbucket.org/asimio/demo-config-properties/src (Zuul-Server-refreshable.yml where routes are dynamically updated).
Look at the refreshable Spring profile settings. This Zuul setup works with both, hard-coding routes url or discovered using Eureka.
It also acting as a Spring Cloud Config client so that routes could be dynamically updated via Git, which is also covered in another blog post: Refreshable Configuration using Spring Cloud Config Server, Spring Cloud Bus, RabbitMQ and Git.
I am new to spring cloud and going through some examples and material available online to make myself comfortable. However, while reading about ZUUL, some sites configured the routes in ZUUL's application.yml and some other sites mentioned that the requests will be forwarded to the respective microservice and no need to explicitly configure the routes. I was bit confused. For ex, in the below scenario what is the approach, to configure routes or to let zuul route automatically?
Let's say i have few micro services running and all of them along with ZUUL are registered to Eureka.
I have a front end which is running on a different port on the same server and needs to interact with the above micro services.
I also have few other applications (Running entirely on different servers) which need to interact with the above micro services for fetching the data.
TIA..
Did you use Zuul (which know microservices address through Eureka) to forward request between your micro-services ? if it's the case, you are using Server-Side Load Balancing pattern.
If you use a discovery service (Eureka in your case), i think the best approach it's to use Client-Side load balancing pattern for all inter-services requests (inside your system). (you can use Ribbon or RestTemplate for that).
You can use Zuul as a unified front door to your system, which allows a browser, mobile app or other user interface to consume services from multiple hosts without managing cross-origin resource sharing (CORS) and authentication for each one.
For example : a client (mobile app) request for all picture comments. The client dont need to know the Comments-service address. Only proxy address needed and Zuul will forward the request to the right service. You can do this in application.yml/.properties by
zuul.routes.comments.path=/comments/**
zuul.routes.comments.service-id=comments
The request will be GET www.myproxy.mycompany.com/comments. Dont forget the service name in your application.yml/.properties is very important (spring.application.name). It's the service-id in Zuul routes (which the same identifier in Eureka).
For some reason, your system need to request external services (as you mentionned in the 3th note). In this case, your external services are not a discovery client, Zuul can't look for the service-id from Eureka. you use routes as
zuul.routes.currencyprovider.path=/currencies/**
zuul.routes.currencyprovider.url=https://currencies.net/
with this route, all /currencies/** requests from your services THROUGH Zuul will be done.
with this approach you have one door for all your system. This is API Gateway pattern.
Sometimes your system need to aggregate multiple results from different services to response to client request. You can do this in Proxy (Zuul in your case).
I am trying to route existing services via Spring cloud Netflix Zuul.
I have an existing service available at below url,
http://localhost:3080/query-service/getquery/1
Out of the box, with zuul I can route to the service as below,
localhost:9000/queryservice-id/queryservice/getquery/1, with "queryservice-id" as the service-id of the service when it is registered in Service Registry. The zuul port is 9000.
I do not want to change the context path and service path information when accessing the service via ZUUL.
With ZUUL, I want to access the service as below,
http://localhost:9000/query-service/getquery/1
I do want to prefix with the "serviceId". This is because I do not want to impact any existing clients of the service. Only the host and port changes, without serviceId.
I was able to accomplish it as below with ZUUL Configuration,
zuul:
routes:
query-service:
path: /query-service/**
serviceId: query-service
stripPrefix: false
With the above configuration, I am able to only use the zuul host and port, the other service specific information remains as before. Seems like stripPrefix is helping in routing without the serviceId.
But, I have a lot of services and will be adding more services too.
For every such service, I do not want to be adding a rule like that to ZUUL configuration which will mean rebuilding and recycling the ZUUL Service.
I feel there should be a simpler and better way to accomplish this, without a big effort, because the change I want to do is common to all services
Is there a way to making this change common for alll the services I want
to be routed via ZUUL.
Thanks,
As checked with the Spring Cloud Netflix team this is recommended approach.
https://github.com/spring-cloud/spring-cloud-netflix/issues/1549