Wrong delimiter '&' in "labelSelector" of KubernetesCatalogWatchContext (spring-cloud-kubernetes-client-discovery)

[cmaune]

We use the lasted version of org.springframework.cloud:spring-cloud-starter-kubernetes-client in combination with the latest spring boot admin release.

We configured two labels for discovery:

spring:
    cloud:
      kubernetes:
        discovery:
            serviceLabels:
                key1: value1
                key2: label2
            namespaces:
                - test

This leads to repeatly can not list endpoints in namespace warn log messages from KubernetesEndpointsCatalogWatch

The APIException thrown in the used io.kubernetes:client-java did not have any (message/stacktrace) helpfull information.

After turning on some http traffic logging we saw this request:

api/v1/namespaces/test/endpoints?labelSelector=key1%3Dvalue1%26key2%3Dvalue2

resulting in

{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"unable to parse requirement: values[0][key1]: Invalid Value \"value1\u0026key2\": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue', or 'my_value', or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')","reason":"BadRequest","code":400}.

Leading to the hint that the delimiter & used here KubernetesCatalogWatchContext::labelSelector is wrong and should be ,

With spring-cloud-starter-kubernetes-fabric8 we had no problems, but there the filtering is done otherwise. Neverless the EndpointsTest from io.fabric8:kubernetes-client shows that the key value pairs should be seperated with ,

Using (same as KubernetesEndpointsCatalogWatch::namespacedEndpoints)

CoreV1Api.listNamespacedEndpoints(namespace, null, null, null, null, labelSelector(labels), null, null, null,	null, null, null)

from io.kubernetes:client-java with a labelSelector() returning a String with , separated Key=Value entries works for multiple labels.

I am unaware of this could be different for varying kubernetes versions.

Sample
Any app that uses org.springframework.cloud:spring-cloud-starter-kubernetes-client and has multiple serviceLables configured in application.yaml for discorvery should reproduce this problem.

[wind57]

When I first read this issue, I was thinking : wait, I remember some tests in this regard that were using a , as the separator and after a bit if digging: here is it

Unfortunately, we were using the correct separator, but only in code related to integration tests and here, this is indeed a bug. Thank you for raising it and fixing it!