How to access member clusters through karmada?

[GitHubxsy]

Users can easily access member clusters through karmada. And supports all APIs of member clusters .Such as get, create, update, etc.
Similar issue #451

[GitHubxsy]

We can achieve cluster/proxy capabilities through AA（apiserver-aggregation）. As shown below：

proxy api：/apis/cluster.karmada.io/v1alpha1/cluster/{clustername}/proxy/api/v1/nodes
The proxy api is divided into three parts：

1. Specify cluster：for example, cluster1
2. proxy： Fixed value
3. proxyurl

reference：

• apiserver-proxy

[XiShanYongYe-Chang]

Our feature is ready now, we can refer user guide here:

https://github.com/karmada-io/karmada/blob/master/docs/userguide/aggregated-api-endpoint.md

[chaunceyjiang]

proxy api：/apis/cluster.karmada.io/v1alpha1/clusters/{clustername}/proxy/api/v1/nodes

https://github.com/karmada-io/karmada/blob/master/pkg/aggregatedapiserver/apiserver.go#L106-L108