fix: only set default --platform flag when it's not changed (#2276)

Signed-off-by: fengxsong <fengxsong@outlook.com>

Signed-off-by: fengxsong <fengxsong@outlook.com>

pkg/buildah/build.go

@@ -21,10 +21,8 @@ import (
 	"strings"
 
 	"github.com/containers/buildah/define"
-
 	"github.com/containers/buildah/imagebuildah"
 	buildahcli "github.com/containers/buildah/pkg/cli"
-	"github.com/containers/buildah/pkg/parse"
 	"github.com/containers/buildah/util"
 	"github.com/spf13/cobra"
 
@@ -79,10 +77,6 @@ func newBuildCommand() *cobra.Command {
 	fromAndBudFlags, err := buildahcli.GetFromAndBudFlags(&fromAndBudResults, &userNSResults, &namespaceResults)
 	bailOnError(err, "failed to setup From and Build flags")
 
-	// set as default, otherwise parse.PlatformsFromOptions will get empty list
-	err = fromAndBudFlags.Set("platform", parse.DefaultPlatform())
-	bailOnError(err, "failed to set default platform flag")
-
 	sopts.RegisterFlags(flags)
 	flags.AddFlagSet(&buildFlags)
 	flags.AddFlagSet(&layerFlags)
@@ -130,9 +124,10 @@ func buildCmd(c *cobra.Command, inputArgs []string, sopts saveOptions, iopts bui
 			return fmt.Errorf("cannot find any of %v in context directory", strings.Join(defaultFileNames, ", "))
 		}
 	}
-	if err := setDefaultFlags(c); err != nil {
+	if err := setDefaultFlagsWithSetters(c, setDefaultPlatformFlag, setDefaultTLSVerifyFlag); err != nil {
 		return err
 	}
+
 	options, containerfiles, removeAll, err := buildahcli.GenBuildOptions(c, inputArgs, iopts)
 	if err != nil {
 		return err

pkg/buildah/common.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/containerd/containerd/platforms"
 	"github.com/containers/buildah"
+	"github.com/containers/buildah/pkg/parse"
 	"github.com/containers/common/pkg/umask"
 	is "github.com/containers/image/v5/storage"
 	"github.com/containers/image/v5/types"
@@ -51,11 +52,12 @@ func flagChanged(c *cobra.Command, name string) bool {
 }
 
 func setDefaultFlags(c *cobra.Command) error {
-	defaulters := []func(*cobra.Command) error{
-		setDefaultTLSVerifyFlag,
-	}
-	for i := range defaulters {
-		if err := defaulters[i](c); err != nil {
+	return setDefaultFlagsWithSetters(c, setDefaultTLSVerifyFlag)
+}
+
+func setDefaultFlagsWithSetters(c *cobra.Command, setters ...func(*cobra.Command) error) error {
+	for i := range setters {
+		if err := setters[i](c); err != nil {
 			return err
 		}
 	}
@@ -63,9 +65,17 @@ func setDefaultFlags(c *cobra.Command) error {
 }
 
 func setDefaultTLSVerifyFlag(c *cobra.Command) error {
-	if fs := c.Flag("tls-verify"); fs != nil && !fs.Changed {
-		if err := c.Flags().Set("tls-verify", "false"); err != nil {
-			return fmt.Errorf("failed to set --tls-verify default to false: %v", err)
+	return setDefaultFlagIfNotChanged(c, "tls-verify", "false")
+}
+
+func setDefaultPlatformFlag(c *cobra.Command) error {
+	return setDefaultFlagIfNotChanged(c, "platform", parse.DefaultPlatform())
+}
+
+func setDefaultFlagIfNotChanged(c *cobra.Command, k, v string) error {
+	if fs := c.Flag(k); fs != nil && !fs.Changed {
+		if err := c.Flags().Set(k, v); err != nil {
+			return fmt.Errorf("failed to set --%s default to %s: %v", k, v, err)
 		}
 	}
 	return nil

pkg/buildah/create.go

@@ -43,12 +43,15 @@ func newCreateCmd() *cobra.Command {
 			if !IsRootless() {
 				return nil
 			}
-			shell, shellSet := os.LookupEnv("SHELL")
-			if !shellSet {
-				logger.Error("no command specified and no `SHELL` env set")
-				os.Exit(1)
+			args = args[1:]
+			if len(args) < 1 {
+				shell, shellSet := os.LookupEnv("SHELL")
+				if !shellSet {
+					logger.Error("no command specified and no `SHELL` env set")
+					os.Exit(1)
+				}
+				args = []string{shell}
 			}
-			args = []string{shell}
 			// nosemgrep: go.lang.security.audit.dangerous-exec-command.dangerous-exec-command
 			cmd := exec.Command(args[0], args[1:]...)
 			cmd.Env = unshare.RootlessEnv()

pkg/buildah/from.go

@@ -226,7 +226,7 @@ func fromCmd(c *cobra.Command, args []string, iopts *fromReply) error {
 	if len(args) > 1 {
 		return errors.New("too many arguments specified")
 	}
-	if err := setDefaultFlags(c); err != nil {
+	if err := setDefaultFlagsWithSetters(c, setDefaultPlatformFlag, setDefaultTLSVerifyFlag); err != nil {
 		return err
 	}
 	if err := auth.CheckAuthFile(iopts.authfile); err != nil {

pkg/buildah/pull.go

@@ -131,7 +131,7 @@ func pullCmd(c *cobra.Command, args []string, iopts *pullOptions) error {
 	if len(args) > 1 {
 		return errors.New("too many arguments specified")
 	}
-	if err := setDefaultFlags(c); err != nil {
+	if err := setDefaultFlagsWithSetters(c, setDefaultPlatformFlag, setDefaultTLSVerifyFlag); err != nil {
 		return err
 	}
 	systemContext, err := parse.SystemContextFromOptions(c)