Kubernetes Services Discovery - Cross Namespace

12/3/2019

I have a kubernetes cluster with serviceA on namespaceA and serviceB on namespaceB.

I want, from serviceA, use kubernetes service discovery to programmatically list serviceB. I am planning to use spring cloud kubernetes ( @EnableDiscoveryClient ).

However, there is a company wide policy to block the use of the configuration below that should have solved the problem: spring.cloud.kubernetes.discovery.all-namespaces=true

Is there any way to circumvent the problem? Maybe assign serviceB to two different namespaces or some other permission/configuration that I am not aware of?

-- guilhermecgs
kubernetes
service-discovery
spring

1 Answer

12/5/2019

If you are trying to simply look up a service IP by service name through Kubernetes API than it should not really matter if you're doing it through kubectl or a Java client, the options you pass to the API are the same.

The thing that matters however is whether the service name would be looked up in the same namespace only or in all namespaces. Accessing a service from a different namespace can be done by specifying its name along with the namespace - instead of my-service they would need to write my-service.some-namespace.

Services without selectors are also an option to expose a service from one namespace to another so that the namespace would be specified in Kubernetes objects and not in app code.

Please let me know if that helps.

-- OhHiMark
Source: StackOverflow