Rename packages

Create separate packages for driver, s3 client and mounters.

pkg/mounter/mounter.go

@@ -0,0 +1,179 @@
+package mounter
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/ctrox/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"
+	goofysMounterType   = "goofys"
+	s3backerMounterType = "s3backer"
+	rcloneMounterType   = "rclone"
+	TypeKey             = "mounter"
+	BucketKey           = "bucket"
+)
+
+// New returns a new mounter depending on the mounterType parameter
+func New(bucket *s3.Bucket, cfg *s3.Config) (Mounter, error) {
+	mounter := bucket.Mounter
+	// Fall back to mounterType in cfg
+	if len(bucket.Mounter) == 0 {
+		mounter = cfg.Mounter
+	}
+	switch mounter {
+	case s3fsMounterType:
+		return newS3fsMounter(bucket, cfg)
+
+	case goofysMounterType:
+		return newGoofysMounter(bucket, cfg)
+
+	case s3backerMounterType:
+		return newS3backerMounter(bucket, cfg)
+
+	case rcloneMounterType:
+		return newRcloneMounter(bucket, cfg)
+
+	default:
+		// default to s3backer
+		return newS3backerMounter(bucket, cfg)
+	}
+}
+
+func fuseMount(path string, command string, args []string) error {
+	cmd := exec.Command(command, args...)
+	glog.V(3).Infof("Mounting fuse with command: %s and args: %s", command, args)
+
+	out, err := cmd.CombinedOutput()
+	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, 1)
+}
+
+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, backoff int) error {
+	if backoff == 20 {
+		return fmt.Errorf("Timeout waiting for PID %v to end", p.Pid)
+	}
+	cmdLine, err := getCmdLine(p.Pid)
+	if err != nil {
+		glog.Warningf("Error checking cmdline of PID %v, assuming it is dead: %s", p.Pid, err)
+		return nil
+	}
+	if cmdLine == "" {
+		// ignore defunct processes
+		// TODO: debug why this happens in the first place
+		// seems to only happen on k8s, not on local docker
+		glog.Warning("Fuse process seems dead, returning")
+		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)
+		return nil
+	}
+	glog.Infof("Fuse process with PID %v still active, waiting...", p.Pid)
+	time.Sleep(time.Duration(backoff*100) * time.Millisecond)
+	return waitForProcess(p, backoff+1)
+}
+
+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
+}