daemon: Remove isWindows const and inline runtime.GOOS check

Other call sites in the package already compare runtime.GOOS directly,
so the per-platform const only added inconsistency. runtime.GOOS is a
compile-time constant, so dead branches are still eliminated.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

daemon/changes.go

@@ -3,6 +3,7 @@ package daemon
 import (
 	"context"
 	"errors"
+	"runtime"
 	"time"
 
 	"github.com/moby/go-archive"
@@ -18,7 +19,7 @@ func (daemon *Daemon) ContainerChanges(ctx context.Context, name string) ([]arch
 		return nil, err
 	}
 
-	if isWindows && container.State.IsRunning() {
+	if runtime.GOOS == "windows" && container.State.IsRunning() {
 		return nil, errors.New("Windows does not support diff of a running container")
 	}
 

daemon/commit.go

@@ -45,7 +45,7 @@ func merge(userConf, imageConf *containertypes.Config) error {
 			imageEnvKey, _, _ := strings.Cut(imageEnv, "=")
 			for _, userEnv := range userConf.Env {
 				userEnvKey, _, _ := strings.Cut(userEnv, "=")
-				if isWindows {
+				if runtime.GOOS == "windows" {
 					// Case insensitive environment variables on Windows
 					found = strings.EqualFold(imageEnvKey, userEnvKey)
 				} else {
@@ -131,7 +131,7 @@ func (daemon *Daemon) CreateImageFromContainer(ctx context.Context, name string,
 	}
 
 	// It is not possible to commit a running container on Windows
-	if isWindows && container.State.IsRunning() {
+	if runtime.GOOS == "windows" && container.State.IsRunning() {
 		return "", errors.Errorf("%+v does not support commit of a running container", runtime.GOOS)
 	}
 

daemon/create.go

@@ -188,7 +188,7 @@ func (daemon *Daemon) create(ctx context.Context, daemonCfg *config.Config, opts
 		}
 		platform = img.Platform()
 		imgID = img.ID()
-	} else if isWindows {
+	} else if runtime.GOOS == "windows" {
 		platform.OS = "linux" // 'scratch' case.
 	}
 

daemon/daemon.go

@@ -886,7 +886,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 	if err != nil {
 		return nil, fmt.Errorf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
 	}
-	if isWindows {
+	if runtime.GOOS == "windows" {
 		if err := os.MkdirAll(realTmp, 0); err != nil {
 			return nil, fmt.Errorf("Unable to create the TempDir (%s): %s", realTmp, err)
 		}
@@ -999,7 +999,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 		return nil, err
 	}
 
-	if isWindows {
+	if runtime.GOOS == "windows" {
 		// Note that permissions (0o700) are ignored on Windows; passing them to
 		// show intent only. We could consider using idtools.MkdirAndChown here
 		// to apply an ACL.
@@ -1064,7 +1064,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 			shim     string
 			shimOpts any
 		)
-		if !isWindows {
+		if runtime.GOOS != "windows" {
 			shim, shimOpts, err = rts.Get("")
 			if err != nil {
 				return nil, err
@@ -1631,7 +1631,7 @@ func (daemon *Daemon) Mount(container *container.Container) error {
 		// The mount path reported by the graph driver should always be trusted on Windows, since the
 		// volume path for a given mounted layer may change over time.  This should only be an error
 		// on non-Windows operating systems.
-		if !isWindows {
+		if runtime.GOOS != "windows" {
 			daemon.Unmount(container)
 			driver := daemon.ImageService().StorageDriver()
 			return fmt.Errorf("driver %s is returning inconsistent paths for container %s ('%s' then '%s')",

daemon/daemon_unix.go

@@ -52,8 +52,6 @@ import (
 )
 
 const (
-	isWindows = false
-
 	// These values were used to adjust the CPU-shares for older API versions,
 	// but were not used for validation.
 	//

daemon/daemon_windows.go

@@ -33,7 +33,6 @@ import (
 )
 
 const (
-	isWindows            = true
 	windowsMinCPUShares  = 1
 	windowsMaxCPUShares  = 10000
 	windowsMinCPUPercent = 1

daemon/export.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"runtime"
 
 	"github.com/containerd/log"
 	"github.com/moby/go-archive"
@@ -23,7 +24,7 @@ func (daemon *Daemon) ContainerExport(ctx context.Context, name string, out io.W
 		return err
 	}
 
-	if isWindows && ctr.ImagePlatform.OS == "windows" {
+	if runtime.GOOS == "windows" && ctr.ImagePlatform.OS == "windows" {
 		return errors.New("the daemon on this operating system does not support exporting Windows containers")
 	}
 

daemon/monitor.go

@@ -2,6 +2,7 @@ package daemon
 
 import (
 	"context"
+	"runtime"
 	"strconv"
 	"strings"
 	"time"
@@ -189,7 +190,7 @@ func (daemon *Daemon) ProcessEvent(id string, e libcontainerdtypes.EventType, ei
 	switch e {
 	case libcontainerdtypes.EventOOM:
 		// StateOOM is Linux specific and should never be hit on Windows
-		if isWindows {
+		if runtime.GOOS == "windows" {
 			return errors.New("received StateOOM from libcontainerd on Windows. This should never happen")
 		}