add option to oc whoami that prints server url

Fixes #11148

Currently there is no "simple" way to obtain the rest api's URL.
This patch adds an option `--show-server-url` || `-u` to `oc whoami`
that retrieves the server url from the first cluster in `config.Cluster`

**Before**

```
$ oc config view --minify -o jsonpath='{.clusters[*].cluster.server}'
https://10.13.137.149:8443% # no linebreak at the end
```

**After**

```
$ oc whoami -u # or --show-server-url
https://10.13.137.149:8443
```

contrib/completions/bash/oc

@@ -13715,6 +13715,8 @@ _oc_whoami()
     flags+=("--show-context")
     flags+=("-c")
     local_nonpersistent_flags+=("--show-context")
+    flags+=("--show-server")
+    local_nonpersistent_flags+=("--show-server")
     flags+=("--show-token")
     flags+=("-t")
     local_nonpersistent_flags+=("--show-token")

contrib/completions/bash/openshift

@@ -18267,6 +18267,8 @@ _openshift_cli_whoami()
     flags+=("--show-context")
     flags+=("-c")
     local_nonpersistent_flags+=("--show-context")
+    flags+=("--show-server")
+    local_nonpersistent_flags+=("--show-server")
     flags+=("--show-token")
     flags+=("-t")
     local_nonpersistent_flags+=("--show-token")

contrib/completions/zsh/oc

@@ -13876,6 +13876,8 @@ _oc_whoami()
     flags+=("--show-context")
     flags+=("-c")
     local_nonpersistent_flags+=("--show-context")
+    flags+=("--show-server")
+    local_nonpersistent_flags+=("--show-server")
     flags+=("--show-token")
     flags+=("-t")
     local_nonpersistent_flags+=("--show-token")

contrib/completions/zsh/openshift

@@ -18428,6 +18428,8 @@ _openshift_cli_whoami()
     flags+=("--show-context")
     flags+=("-c")
     local_nonpersistent_flags+=("--show-context")
+    flags+=("--show-server")
+    local_nonpersistent_flags+=("--show-server")
     flags+=("--show-token")
     flags+=("-t")
     local_nonpersistent_flags+=("--show-token")

docs/man/man1/oc-whoami.1

@@ -26,6 +26,10 @@ user context.
 \fB\-c\fP, \fB\-\-show\-context\fP=false
     Print the current user context name
 
+.PP
+\fB\-\-show\-server\fP=false
+    Print the current server's REST API URL
+
 .PP
 \fB\-t\fP, \fB\-\-show\-token\fP=false
     Print the token the current session is using. This will return an error if you are using a different form of authentication.

docs/man/man1/openshift-cli-whoami.1

@@ -26,6 +26,10 @@ user context.
 \fB\-c\fP, \fB\-\-show\-context\fP=false
     Print the current user context name
 
+.PP
+\fB\-\-show\-server\fP=false
+    Print the current server's REST API URL
+
 .PP
 \fB\-t\fP, \fB\-\-show\-token\fP=false
     Print the token the current session is using. This will return an error if you are using a different form of authentication.

pkg/cmd/cli/cmd/whoami.go

@@ -53,6 +53,7 @@ func NewCmdWhoAmI(name, fullName string, f *clientcmd.Factory, out io.Writer) *c
 
 	cmd.Flags().BoolP("show-token", "t", false, "Print the token the current session is using. This will return an error if you are using a different form of authentication.")
 	cmd.Flags().BoolP("show-context", "c", false, "Print the current user context name")
+	cmd.Flags().Bool("show-server", false, "Print the current server's REST API URL")
 
 	return cmd
 }
@@ -89,6 +90,17 @@ func RunWhoAmI(f *clientcmd.Factory, out io.Writer, cmd *cobra.Command, args []s
 		fmt.Fprintf(out, "%s\n", cfg.CurrentContext)
 		return nil
 	}
+	if kcmdutil.GetFlagBool(cmd, "show-server") {
+		cfg, err := f.OpenShiftClientConfig.RawConfig()
+		if err != nil {
+			return err
+		}
+		for _, c := range cfg.Clusters {
+			fmt.Fprintf(out, "%s\n", c.Server)
+			return nil
+		}
+		return fmt.Errorf("unable to get clusters. Cannot retrieve server URL.")
+	}
 
 	client, _, err := f.Clients()
 	if err != nil {

test/cmd/whoami.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+source "$(dirname "${BASH_SOURCE}")/../../hack/lib/init.sh"
+trap os::test::junit::reconcile_output EXIT
+
+# Cleanup cluster resources created by this test
+(
+  set +e
+  oc delete all,templates --all
+  exit 0
+) &>/dev/null
+
+
+os::test::junit::declare_suite_start "cmd/whoami"
+# This test validates the whoami command's --show-server flag
+os::cmd::expect_success_and_text 'oc whoami --show-server' 'http(s)?:\/\/[0-9\.]+\:[0-9]+'
+
+echo "whoami: ok"
+os::test::junit::declare_suite_end