feat: add discovery k8s dump data interface

[hanqingwu]

Description

Fix: #11057

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[shreemaan-abhishek]

Test cases are also needed.

[hanqingwu]

I have not find a k8s mock apiserver like one in the test case

[shreemaan-abhishek]

is this what you are looking for? https://github.com/shreemaan-abhishek/apisix/blob/5319503293c41cf41a2caa5cb944a12d40686c83/t/kubernetes/discovery/kubernetes.t#L38-L97

[hanqingwu]

@shreemaan-abhishek ，Thanks , I have found the method build k8s test env in workflows/kubernetes-ci.yml .

[shreemaan-abhishek]

--- response_body_like
.*"endpoints".*

this doesn't seem sufficient to show that the feature works fine. The verification should be more descriptive.

[shreemaan-abhishek]

@hanqingwu should we add docs as well? Also, could you please show how the response body looks like?

[hanqingwu]

yes, we should add docs
response like this:
{"endpoints":[{"id":"first","endpoints":[{"name":"default/kubernetes","value":"{\"https\":[{\"host\":\"172.18.0.2\",\"port\":6443,\"weight\":50}]}"},{"name":"kube-system/kube-dns","value":"{\"dns-tcp\":[{\"host\":\"10.244.0.3\",\"port\":53,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":53,\"weight\":50}],\"dns\":[{\"host\":\"10.244.0.3\",\"port\":53,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":53,\"weight\":50}],\"metrics\":[{\"host\":\"10.244.0.3\",\"port\":9153,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":9153,\"weight\":50}]}"},{"name":"local-path-storage/rancher.io-local-path","value":"{}"},{"name":"ns-a/ep","value":"{}"},{"name":"ns-b/ep","value":"{}"},{"name":"ns-c/ep","value":"{}"}]},{"id":"second","endpoints":[{"name":"default/kubernetes","value":"{\"https\":[{\"host\":\"172.18.0.2\",\"port\":6443,\"weight\":50}]}"},{"name":"kube-system/kube-dns","value":"{\"dns-tcp\":[{\"host\":\"10.244.0.3\",\"port\":53,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":53,\"weight\":50}],\"dns\":[{\"host\":\"10.244.0.3\",\"port\":53,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":53,\"weight\":50}],\"metrics\":[{\"host\":\"10.244.0.3\",\"port\":9153,\"weight\":50},{\"host\":\"10.244.0.4\",\"port\":9153,\"weight\":50}]}"},{"name":"local-path-storage/rancher.io-local-path","value":"{}"},{"name":"ns-a/ep","value":"{}"},{"name":"ns-b/ep","value":"{}"},{"name":"ns-c/ep","value":"{}"}]}],"config":[{"id":"first","client":{"token_file":"/tmp/var/run/secrets/kubernetes.io/serviceaccount/token"},"service":{"host":"127.0.0.1","schema":"https","port":"6443"},"watch_endpoint_slices":true,"default_weight":50,"shared_size":"1m"},{"id":"second","client":{"token_file":"/tmp/var/run/secrets/kubernetes.io/serviceaccount/token"},"service":{"host":"127.0.0.1","schema":"http","port":"6445"},"watch_endpoint_slices":true,"default_weight":50,"shared_size":"1m"}]}

[shreemaan-abhishek]

Please add docs then.

[shreemaan-abhishek]

Suggested change

	GET /v1/discovery/kubernetes/dump
	curl http://127.0.0.1:9090/v1/discovery/kubernetes/dump | jq