Add jsonpath approach for apiserver query (#12350)

* Add `jsonpath` approach for apiserver query

* Refine the wording with the approach description

* Refine the command log

* Move the itemized number back

content/en/docs/tasks/access-application-cluster/access-cluster.md

@@ -78,9 +78,35 @@ $ curl http://localhost:8080/api/
 
 Use `kubectl describe secret...` to get the token for the default service account:
 
+Use `kubectl describe secret` with grep/cut:
+
 ```shell
 $ APISERVER=$(kubectl config view --minify | grep server | cut -f 2- -d ":" | tr -d " ")
-$ TOKEN=$(kubectl describe secret $(kubectl get secrets | grep "^default" | cut -f1 -d ' ') | grep -E '^token' | cut -f2 -d':' | tr -d " ")
+$ SECRET_NAME=$(kubectl get secrets | grep ^default | cut -f1 -d ' ')
+$ TOKEN=$(kubectl describe secret $SECRET_NAME | grep -E '^token' | cut -f2 -d':' | tr -d " ")
+
+$ curl $APISERVER/api --header "Authorization: Bearer $TOKEN" --insecure
+{
+  "kind": "APIVersions",
+  "versions": [
+    "v1"
+  ],
+  "serverAddressByClientCIDRs": [
+    {
+      "clientCIDR": "0.0.0.0/0",
+      "serverAddress": "10.0.1.149:443"
+    }
+  ]
+}
+```
+
+Using `jsonpath`:
+
+```shell
+$ APISERVER=$(kubectl config view --minify -o jsonpath='{.clusters[0].cluster.server}')
+$ SECRET_NAME=$(kubectl get serviceaccount default -o jsonpath='{.secrets[0].name}')
+$ TOKEN=$(kubectl get secret $SECRET_NAME -o jsonpath='{.data.token}' | base64 --decode)
+
 $ curl $APISERVER/api --header "Authorization: Bearer $TOKEN" --insecure
 {
   "kind": "APIVersions",

content/en/docs/tasks/administer-cluster/access-cluster-api.md

@@ -85,6 +85,8 @@ The output is similar to this:
 It is possible to avoid using kubectl proxy by passing an authentication token
 directly to the API server, like this:
 
+Using `grep/cut` approach:
+
 ``` shell
 # Check all possible clusters, as you .KUBECONFIG may have multiple contexts
 kubectl config view -o jsonpath='{range .clusters[*]}{.name}{"\t"}{.cluster.server}{"\n"}{end}'
@@ -116,6 +118,26 @@ The output is similar to this:
 }
 ```
 
+Using `jsonpath` approach:
+
+```
+$ APISERVER=$(kubectl config view --minify -o jsonpath='{.clusters[0].cluster.server}')
+$ TOKEN=$(kubectl get secret $(kubectl get serviceaccount default -o jsonpath='{.secrets[0].name}') -o jsonpath='{.data.token}' | base64 --decode )
+$ curl $APISERVER/api --header "Authorization: Bearer $TOKEN" --insecure
+{
+  "kind": "APIVersions",
+  "versions": [
+    "v1"
+  ],
+  "serverAddressByClientCIDRs": [
+    {
+      "clientCIDR": "0.0.0.0/0",
+      "serverAddress": "10.0.1.149:443"
+    }
+  ]
+}
+```
+
 The above example uses the `--insecure` flag. This leaves it subject to MITM
 attacks. When kubectl accesses the cluster it uses a stored root certificate
 and client certificates to access the server. (These are installed in the