Warn about ignored password in auth command (like in login)

We ignore the password when authenticating against Kubernetes in both
commands.

[cloudfoundry/korifi#2195]

Co-authored-by: Dave Walter <walterda@vmware.com>

command/v7/auth_command.go

@@ -118,11 +118,18 @@ func (cmd AuthCommand) getUsernamePassword() (string, string, error) {
 	if password == "" {
 		if envPassword := cmd.Config.CFPassword(); envPassword != "" {
 			password = envPassword
-		} else if !cmd.Config.IsCFOnK8s() {
+		} else {
 			passwordMissing = true
 		}
 	}
 
+	if cmd.Config.IsCFOnK8s() {
+		if !passwordMissing {
+			cmd.UI.DisplayWarning("Warning: password is ignored when authenticating against Kubernetes.")
+		}
+		passwordMissing = false
+	}
+
 	if userMissing || passwordMissing {
 		return "", "", translatableerror.MissingCredentialsError{
 			MissingUsername: userMissing,

command/v7/auth_command_test.go

@@ -124,6 +124,24 @@ var _ = Describe("auth Command", func() {
 				})
 			})
 		})
+
+		When("the password is given", func() {
+			BeforeEach(func() {
+				cmd.RequiredArgs.Username = "myuser"
+				cmd.RequiredArgs.Password = "mypassword"
+			})
+
+			When("authenticating against korifi", func() {
+				BeforeEach(func() {
+					fakeConfig.IsCFOnK8sReturns(true)
+				})
+
+				It("succeeds but warns", func() {
+					Expect(err).NotTo(HaveOccurred())
+					Expect(testUI.Err).To(Say("Warning: password is ignored when authenticating against Kubernetes."))
+				})
+			})
+		})
 	})
 
 	When("there is an auth error", func() {