package mounter import ( "errors" "fmt" "io/ioutil" "math" "os" "os/exec" "strings" "syscall" "time" "github.com/yandex-cloud/k8s-csi-s3/pkg/s3" "github.com/golang/glog" "github.com/mitchellh/go-ps" "k8s.io/kubernetes/pkg/util/mount" ) // Mounter interface which can be implemented // by the different mounter types type Mounter interface { Stage(stagePath string) error Unstage(stagePath string) error Mount(source string, target string) error } const ( s3fsMounterType = "s3fs" geesefsMounterType = "geesefs" rcloneMounterType = "rclone" TypeKey = "mounter" BucketKey = "bucket" OptionsKey = "options" ) // New returns a new mounter depending on the mounterType parameter func New(meta *s3.FSMeta, cfg *s3.Config) (Mounter, error) { mounter := meta.Mounter // Fall back to mounterType in cfg if len(meta.Mounter) == 0 { mounter = cfg.Mounter } switch mounter { case geesefsMounterType: return newGeeseFSMounter(meta, cfg) case s3fsMounterType: return newS3fsMounter(meta, cfg) case rcloneMounterType: return newRcloneMounter(meta, cfg) default: // default to GeeseFS return newGeeseFSMounter(meta, cfg) } } func fuseMount(path string, command string, args []string) error { cmd := exec.Command(command, args...) cmd.Stderr = os.Stderr glog.V(3).Infof("Mounting fuse with command: %s and args: %s", command, args) out, err := cmd.Output() if err != nil { return fmt.Errorf("Error fuseMount command: %s\nargs: %s\noutput: %s", command, args, out) } return waitForMount(path, 10*time.Second) } func FuseUnmount(path string) error { if err := mount.New("").Unmount(path); err != nil { return err } // as fuse quits immediately, we will try to wait until the process is done process, err := findFuseMountProcess(path) if err != nil { glog.Errorf("Error getting PID of fuse mount: %s", err) return nil } if process == nil { glog.Warningf("Unable to find PID of fuse mount %s, it must have finished already", path) return nil } glog.Infof("Found fuse pid %v of mount %s, checking if it still runs", process.Pid, path) return waitForProcess(process, 20) } func waitForMount(path string, timeout time.Duration) error { var elapsed time.Duration var interval = 10 * time.Millisecond for { notMount, err := mount.New("").IsNotMountPoint(path) if err != nil { return err } if !notMount { return nil } time.Sleep(interval) elapsed = elapsed + interval if elapsed >= timeout { return errors.New("Timeout waiting for mount") } } } func findFuseMountProcess(path string) (*os.Process, error) { processes, err := ps.Processes() if err != nil { return nil, err } for _, p := range processes { cmdLine, err := getCmdLine(p.Pid()) if err != nil { glog.Errorf("Unable to get cmdline of PID %v: %s", p.Pid(), err) continue } if strings.Contains(cmdLine, path) { glog.Infof("Found matching pid %v on path %s", p.Pid(), path) return os.FindProcess(p.Pid()) } } return nil, nil } func waitForProcess(p *os.Process, limit int) error { for backoff := 0; backoff < limit; backoff++ { cmdLine, err := getCmdLine(p.Pid) if err != nil { glog.Warningf("Error checking cmdline of PID %v, assuming it is dead: %s", p.Pid, err) p.Wait() return nil } if cmdLine == "" { glog.Warning("Fuse process seems dead, returning") p.Wait() return nil } if err := p.Signal(syscall.Signal(0)); err != nil { glog.Warningf("Fuse process does not seem active or we are unprivileged: %s", err) p.Wait() return nil } glog.Infof("Fuse process with PID %v still active, waiting...", p.Pid) time.Sleep(time.Duration(math.Pow(1.5, float64(backoff))*100) * time.Millisecond) } p.Release() return fmt.Errorf("Timeout waiting for PID %v to end", p.Pid) } func getCmdLine(pid int) (string, error) { cmdLineFile := fmt.Sprintf("/proc/%v/cmdline", pid) cmdLine, err := ioutil.ReadFile(cmdLineFile) if err != nil { return "", err } return string(cmdLine), nil } func createLoopDevice(device string) error { if _, err := os.Stat(device); !os.IsNotExist(err) { return nil } args := []string{ device, "b", "7", "0", } cmd := exec.Command("mknod", args...) out, err := cmd.CombinedOutput() if err != nil { return fmt.Errorf("Error configuring loop device: %s", out) } return nil }