Provide several sub-commands only on Linux

They won't work on non-Linux systems anyways.

Use build flags to add platform-specific sub-commands instead of runtime
checks. Also add build tag to files that only make sense on specific
platforms. This includes Autopilot, as this relies on the status socket,
which is not available on Windows at the moment.

Signed-off-by: Tom Wieczorek <twieczorek@mirantis.com>

cmd/controller/controller.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 /*
 Copyright 2021 k0s authors
 

cmd/controller/controller_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package controller_test
 
 import (
+	"runtime"
 	"strconv"
 	"strings"
 	"testing"
@@ -28,6 +29,10 @@ import (
 )
 
 func TestControllerCmd_Help(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip("Running controllers is only supported on Linux")
+	}
+
 	defaultConfigPath := strconv.Quote(constant.K0sConfigPathDefault)
 	defaultDataDir := strconv.Quote(constant.DataDirDefault)
 

cmd/install/controller.go

@@ -1,3 +1,5 @@
+//go:build linux
+
 /*
 Copyright 2021 k0s authors
 

cmd/install/controller_test.go

@@ -1,3 +1,5 @@
+//go:build linux
+
 /*
 Copyright 2024 k0s authors
 

cmd/install/install.go

@@ -37,8 +37,9 @@ func NewInstallCmd() *cobra.Command {
 		Run:   func(*cobra.Command, []string) { /* Enforce arg validation. */ },
 	}
 
-	cmd.AddCommand(installControllerCmd(&installFlags))
 	cmd.AddCommand(installWorkerCmd(&installFlags))
+	addPlatformSpecificCommands(cmd, &installFlags)
+
 	cmd.PersistentFlags().BoolVar(&installFlags.force, "force", false, "force init script creation")
 	cmd.PersistentFlags().StringArrayVarP(&installFlags.envVars, "env", "e", nil, "set environment variable")
 	cmd.PersistentFlags().AddFlagSet(config.GetPersistentFlagSet())

cmd/restore/restore_windows.go → cmd/install/install_linux.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2021 k0s authors
+Copyright 2025 k0s authors
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,22 +14,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package restore
+package install
 
 import (
-	"errors"
-
 	"github.com/spf13/cobra"
 )
 
-var restoredConfigPath string
-
-func NewRestoreCmd() *cobra.Command {
-	return &cobra.Command{
-		Use:   "restore",
-		Short: "restore k0s state from given backup archive. Not supported in Windows OS",
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return errors.New("unsupported Operating System for this command")
-		},
-	}
+func addPlatformSpecificCommands(install *cobra.Command, installFlags *installFlags) {
+	install.AddCommand(installControllerCmd(installFlags))
 }

cmd/install/install_other.go

@@ -0,0 +1,25 @@
+//go:build !linux
+
+/*
+Copyright 2025 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package install
+
+import "github.com/spf13/cobra"
+
+func addPlatformSpecificCommands(*cobra.Command, *installFlags) {
+	// no-op
+}

cmd/install/worker.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"runtime"
 
 	"github.com/spf13/cobra"
 
@@ -37,7 +38,7 @@ All default values of worker command will be passed to the service stub unless o
 Windows flags like "--api-server", "--cidr-range" and "--cluster-dns" will be ignored since install command doesn't yet support Windows services`,
 		Args: cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			if os.Geteuid() != 0 {
+			if runtime.GOOS != "windows" && os.Geteuid() != 0 {
 				return errors.New("this command must be run as root")
 			}
 

cmd/reset/reset.go

@@ -1,3 +1,5 @@
+//go:build linux
+
 /*
 Copyright 2021 k0s authors
 

cmd/root.go

@@ -20,22 +20,16 @@ import (
 	"errors"
 	"net/http"
 	"os"
-	"runtime"
 
 	"github.com/k0sproject/k0s/cmd/airgap"
 	"github.com/k0sproject/k0s/cmd/api"
-	"github.com/k0sproject/k0s/cmd/backup"
 	configcmd "github.com/k0sproject/k0s/cmd/config"
-	"github.com/k0sproject/k0s/cmd/controller"
 	"github.com/k0sproject/k0s/cmd/ctr"
 	"github.com/k0sproject/k0s/cmd/etcd"
 	"github.com/k0sproject/k0s/cmd/install"
 	"github.com/k0sproject/k0s/cmd/kubeconfig"
 	"github.com/k0sproject/k0s/cmd/kubectl"
-	"github.com/k0sproject/k0s/cmd/reset"
-	"github.com/k0sproject/k0s/cmd/restore"
 	"github.com/k0sproject/k0s/cmd/start"
-	"github.com/k0sproject/k0s/cmd/status"
 	"github.com/k0sproject/k0s/cmd/stop"
 	"github.com/k0sproject/k0s/cmd/sysinfo"
 	"github.com/k0sproject/k0s/cmd/token"
@@ -82,24 +76,13 @@ func NewRootCmd() *cobra.Command {
 
 	cmd.AddCommand(airgap.NewAirgapCmd())
 	cmd.AddCommand(api.NewAPICmd())
-	cmd.AddCommand(backup.NewBackupCmd())
-	cmd.AddCommand(controller.NewControllerCmd())
 	cmd.AddCommand(ctr.NewCtrCommand())
 	cmd.AddCommand(configcmd.NewConfigCmd())
 	cmd.AddCommand(etcd.NewEtcdCmd())
 	cmd.AddCommand(install.NewInstallCmd())
 	cmd.AddCommand(kubeconfig.NewKubeConfigCmd())
 	cmd.AddCommand(kubectl.NewK0sKubectlCmd())
-	if runtime.GOOS == "linux" {
-		// Currently only supported on Linux
-		cmd.AddCommand(reset.NewResetCmd())
-	}
-	cmd.AddCommand(restore.NewRestoreCmd())
 	cmd.AddCommand(start.NewStartCmd())
-	if runtime.GOOS == "linux" {
-		// Currently only supported on Linux
-		cmd.AddCommand(status.NewStatusCmd())
-	}
 	cmd.AddCommand(stop.NewStopCmd())
 	cmd.AddCommand(sysinfo.NewSysinfoCmd())
 	cmd.AddCommand(token.NewTokenCmd())
@@ -109,6 +92,8 @@ func NewRootCmd() *cobra.Command {
 	cmd.AddCommand(newCompletionCmd())
 	cmd.AddCommand(newDocsCmd())
 
+	addPlatformSpecificCommands(cmd)
+
 	cmd.DisableAutoGenTag = true
 	longDesc = "k0s - The zero friction Kubernetes - https://k0sproject.io"
 	if build.EulaNotice != "" {

cmd/root_linux.go

@@ -0,0 +1,35 @@
+/*
+Copyright 2025 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"github.com/k0sproject/k0s/cmd/backup"
+	"github.com/k0sproject/k0s/cmd/controller"
+	"github.com/k0sproject/k0s/cmd/reset"
+	"github.com/k0sproject/k0s/cmd/restore"
+	"github.com/k0sproject/k0s/cmd/status"
+
+	"github.com/spf13/cobra"
+)
+
+func addPlatformSpecificCommands(root *cobra.Command) {
+	root.AddCommand(backup.NewBackupCmd())
+	root.AddCommand(controller.NewControllerCmd())
+	root.AddCommand(reset.NewResetCmd())
+	root.AddCommand(restore.NewRestoreCmd())
+	root.AddCommand(status.NewStatusCmd())
+}

pkg/cleanup/bridge_other.go → cmd/root_other.go

@@ -1,7 +1,7 @@
 //go:build !linux
 
 /*
-Copyright 2021 k0s authors
+Copyright 2025 k0s authors
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -16,8 +16,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package cleanup
+package cmd
 
-func newBridgeStep() Step {
-	return nil
-}
+import "github.com/spf13/cobra"
+
+func addPlatformSpecificCommands(root *cobra.Command) { /* no-op */ }

cmd/root_test.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"runtime"
 	"slices"
 	"strings"
 	"testing"
@@ -75,12 +76,16 @@ func TestRootCmd_Flags(t *testing.T) {
 
 func TestUnknownSubCommandsAreRejected(t *testing.T) {
 	commandsWithArguments := []string{
-		"controller",
 		"kubeconfig create",
-		"restore",
 		"token invalidate",
 		"worker",
 	}
+	if runtime.GOOS == "linux" {
+		commandsWithArguments = append(commandsWithArguments,
+			"controller",
+			"restore",
+		)
+	}
 	t.Cleanup(func() {
 		if !t.Failed() {
 			assert.Empty(t, commandsWithArguments, "Some sub-commands are listed unnecessarily")

cmd/start/start.go

@@ -19,6 +19,7 @@ package start
 import (
 	"errors"
 	"os"
+	"runtime"
 
 	"github.com/k0sproject/k0s/pkg/install"
 
@@ -32,7 +33,7 @@ func NewStartCmd() *cobra.Command {
 		Short: "Start the k0s service configured on this host. Must be run as root (or with sudo)",
 		Args:  cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			if os.Geteuid() != 0 {
+			if runtime.GOOS != "windows" && os.Geteuid() != 0 {
 				return errors.New("this command must be run as root")
 			}
 			svc, err := install.InstalledService()

cmd/status/status.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 /*
 Copyright 2021 k0s authors
 

cmd/stop/stop.go

@@ -19,6 +19,7 @@ package stop
 import (
 	"errors"
 	"os"
+	"runtime"
 
 	"github.com/k0sproject/k0s/pkg/install"
 
@@ -32,7 +33,7 @@ func NewStopCmd() *cobra.Command {
 		Short: "Stop the k0s service configured on this host. Must be run as root (or with sudo)",
 		Args:  cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			if os.Geteuid() != 0 {
+			if runtime.GOOS != "windows" && os.Geteuid() != 0 {
 				return errors.New("this command must be run as root")
 			}
 			svc, err := install.InstalledService()

cmd/token/create.go

@@ -1,3 +1,5 @@
+//go:build unix
+
 /*
 Copyright 2021 k0s authors
 

cmd/token/token.go

@@ -32,10 +32,11 @@ func NewTokenCmd() *cobra.Command {
 		Run:   func(*cobra.Command, []string) { /* Enforce arg validation. */ },
 	}
 
-	cmd.AddCommand(tokenCreateCmd())
 	cmd.AddCommand(tokenListCmd())
 	cmd.AddCommand(tokenInvalidateCmd())
 	cmd.AddCommand(preSharedCmd())
+	addPlatformSpecificCommands(cmd)
+
 	return cmd
 }
 

cmd/token/token_other.go

@@ -0,0 +1,25 @@
+//go:build !unix
+
+/*
+Copyright 2025 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package token
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func addPlatformSpecificCommands(*cobra.Command) { /* no-op */ }

cmd/backup/backup_windows.go → cmd/token/token_unix.go

@@ -1,5 +1,7 @@
+//go:build unix
+
 /*
-Copyright 2021 k0s authors
+Copyright 2025 k0s authors
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,23 +16,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package backup
+package token
 
 import (
-	"errors"
-
 	"github.com/spf13/cobra"
 )
 
-var savePath string
-
-func NewBackupCmd() *cobra.Command {
-	return &cobra.Command{
-		Use:   "backup",
-		Short: "Back-Up k0s configuration. Not supported on Windows OS",
-		Args:  cobra.NoArgs,
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return errors.New("unsupported Operating System for this command")
-		},
-	}
+func addPlatformSpecificCommands(token *cobra.Command) {
+	token.AddCommand(tokenCreateCmd())
 }