func()

in mount_linux.go [144:200]

• 26 lines of code
• 7 McCabe index (conditional complexity)

func (mounter *Mounter) doMount(mounterPath string, mountCmd string, source string, target string, fstype string, options []string, sensitiveOptions []string, mountFlags []string, systemdMountRequired bool) error {
	mountArgs, mountArgsLogStr := MakeMountArgsSensitiveWithMountFlags(source, target, fstype, options, sensitiveOptions, mountFlags)
	if len(mounterPath) > 0 {
		mountArgs = append([]string{mountCmd}, mountArgs...)
		mountArgsLogStr = mountCmd + " " + mountArgsLogStr
		mountCmd = mounterPath
	}

	if mounter.withSystemd && systemdMountRequired {
		// Try to run mount via systemd-run --scope. This will escape the
		// service where kubelet runs and any fuse daemons will be started in a
		// specific scope. kubelet service than can be restarted without killing
		// these fuse daemons.
		//
		// Complete command line (when mounterPath is not used):
		// systemd-run --description=... --scope -- mount -t <type> <what> <where>
		//
		// Expected flow:
		// * systemd-run creates a transient scope (=~ cgroup) and executes its
		//   argument (/bin/mount) there.
		// * mount does its job, forks a fuse daemon if necessary and finishes.
		//   (systemd-run --scope finishes at this point, returning mount's exit
		//   code and stdout/stderr - thats one of --scope benefits).
		// * systemd keeps the fuse daemon running in the scope (i.e. in its own
		//   cgroup) until the fuse daemon dies (another --scope benefit).
		//   Kubelet service can be restarted and the fuse daemon survives.
		// * When the fuse daemon dies (e.g. during unmount) systemd removes the
		//   scope automatically.
		//
		// systemd-mount is not used because it's too new for older distros
		// (CentOS 7, Debian Jessie).
		mountCmd, mountArgs, mountArgsLogStr = AddSystemdScopeSensitive("systemd-run", target, mountCmd, mountArgs, mountArgsLogStr)
		// } else {
		// No systemd-run on the host (or we failed to check it), assume kubelet
		// does not run as a systemd service.
		// No code here, mountCmd and mountArgs are already populated.
	}

	// Logging with sensitive mount options removed.
	klog.V(4).Infof("Mounting cmd (%s) with arguments (%s)", mountCmd, mountArgsLogStr)
	command := exec.Command(mountCmd, mountArgs...)
	output, err := command.CombinedOutput()
	if err != nil {
		if err.Error() == errNoChildProcesses {
			if command.ProcessState.Success() {
				// We don't consider errNoChildProcesses an error if the process itself succeeded (see - k/k issue #103753).
				return nil
			}
			// Rewrite err with the actual exit error of the process.
			err = &exec.ExitError{ProcessState: command.ProcessState}
		}
		klog.Errorf("Mount failed: %v\nMounting command: %s\nMounting arguments: %s\nOutput: %s\n", err, mountCmd, mountArgsLogStr, string(output))
		return fmt.Errorf("mount failed: %v\nMounting command: %s\nMounting arguments: %s\nOutput: %s",
			err, mountCmd, mountArgsLogStr, string(output))
	}
	return err
}