Allow additional Rootless CopyUpDirs through K3S_ROOTLESS_COPYUPDIRS env variable (#10386)

pkg/rootless/rootless.go

@@ -32,6 +32,7 @@ var (
 	enableIPv6Env      = "K3S_ROOTLESS_ENABLE_IPV6"
 	portDriverEnv      = "K3S_ROOTLESS_PORT_DRIVER"
 	disableLoopbackEnv = "K3S_ROOTLESS_DISABLE_HOST_LOOPBACK"
+	copyUpDirsEnv      = "K3S_ROOTLESS_COPYUPDIRS"
 )
 
 func Rootless(stateDir string, enableIPv6 bool) error {
@@ -218,6 +219,9 @@ func createChildOpt(driver portDriver) (*child.Opt, error) {
 	opt.NetworkDriver = slirp4netns.NewChildDriver()
 	opt.PortDriver = driver.NewChildDriver()
 	opt.CopyUpDirs = []string{"/etc", "/var/run", "/run", "/var/lib"}
+	if copyUpDirs := os.Getenv(copyUpDirsEnv); copyUpDirs != "" {
+		opt.CopyUpDirs = append(opt.CopyUpDirs, strings.Split(copyUpDirs, ",")...)
+	}
 	opt.CopyUpDriver = tmpfssymlink.NewChildDriver()
 	opt.MountProcfs = true
 	opt.Reaper = true