cmd/headscale/cli: move errMissingParameter and Error type to their users

Move errMissingParameter from users.go to utils.go alongside the
other shared sentinel errors; the variable is referenced by
api_key.go and preauthkeys.go.

Move the Error constant-error type from debug.go to mockoidc.go,
its only consumer.

cmd/headscale/cli/debug.go

@@ -9,11 +9,6 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// Error is used to compare errors as per https://dave.cheney.net/2016/04/07/constant-errors
-type Error string
-
-func (e Error) Error() string { return string(e) }
-
 func init() {
 	rootCmd.AddCommand(debugCmd)
 

cmd/headscale/cli/mockoidc.go

@@ -16,6 +16,11 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// Error is used to compare errors as per https://dave.cheney.net/2016/04/07/constant-errors
+type Error string
+
+func (e Error) Error() string { return string(e) }
+
 const (
 	errMockOidcClientIDNotDefined     = Error("MOCKOIDC_CLIENT_ID not defined")
 	errMockOidcClientSecretNotDefined = Error("MOCKOIDC_CLIENT_SECRET not defined")

cmd/headscale/cli/users.go

@@ -61,8 +61,6 @@ func init() {
 	mustMarkRequired(renameUserCmd, "new-name")
 }
 
-var errMissingParameter = errors.New("missing parameters")
-
 var userCmd = &cobra.Command{
 	Use:     "users",
 	Short:   "Manage the users of Headscale",

cmd/headscale/cli/utils.go

@@ -33,7 +33,10 @@ const (
 	outputFormatYAML     = "yaml"
 )
 
-var errAPIKeyNotSet = errors.New("HEADSCALE_CLI_API_KEY environment variable needs to be set")
+var (
+	errAPIKeyNotSet     = errors.New("HEADSCALE_CLI_API_KEY environment variable needs to be set")
+	errMissingParameter = errors.New("missing parameters")
+)
 
 // mustMarkRequired marks the named flags as required on cmd, panicking
 // if any name does not match a registered flag.  This is only called