setup: Add InVm option to Validate()

If in vm, we don't need --privileged. Also, we can also support
rootless containers.

Author: alexlarsson

cmd/image-builder/bib_main.go

@@ -282,7 +282,7 @@ func bibCmdBuild(cmd *cobra.Command, args []string) error {
 	progressType, _ := cmd.Flags().GetString("progress")
 
 	logrus.Debug("Validating environment")
-	if err := setup.Validate(targetArch); err != nil {
+	if err := setup.Validate(targetArch, false); err != nil {
 		return fmt.Errorf("cannot validate the setup: %w", err)
 	}
 	logrus.Debug("Ensuring environment setup")

pkg/setup/setup.go

@@ -82,12 +82,12 @@ func EnsureEnvironment(storePath string, inVm bool) error {
 
 // Validate checks that the environment is supported (e.g. caller set up the
 // container correctly)
-func Validate(targetArch string) error {
+func Validate(targetArch string, inVm bool) error {
 	isRootless, err := podmanutil.IsRootless()
 	if err != nil {
 		return fmt.Errorf("checking rootless: %w", err)
 	}
-	if isRootless {
+	if isRootless && !inVm {
 		return fmt.Errorf("this command must be run in rootful (not rootless) podman")
 	}
 
@@ -97,7 +97,7 @@ func Validate(targetArch string) error {
 	if err := unix.Statfs("/sys", &stvfsbuf); err != nil {
 		return fmt.Errorf("failed to stat /sys: %w", err)
 	}
-	if (stvfsbuf.Flags & unix.ST_RDONLY) > 0 {
+	if !inVm && (stvfsbuf.Flags&unix.ST_RDONLY) > 0 {
 		return fmt.Errorf("this command requires a privileged container")
 	}