Add ci pipeline with GitLab (#3)

* Add automated testing
* Create loop device while staging s3backer

pkg/s3/mounter_s3backer.go

@@ -27,6 +27,8 @@ const (
 	// blockSize to use in k
 	s3backerBlockSize   = "128k"
 	s3backerDefaultSize = 1024 * 1024 * 1024 // 1GiB
+	// S3backerLoopDevice the loop device required by s3backer
+	S3backerLoopDevice = "/dev/loop0"
 )
 
 func newS3backerMounter(bucket *bucket, cfg *Config) (Mounter, error) {
@@ -55,6 +57,10 @@ func (s3backer *s3backerMounter) String() string {
 }
 
 func (s3backer *s3backerMounter) Stage(stageTarget string) error {
+	// s3backer uses the loop device
+	if err := createLoopDevice(S3backerLoopDevice); err != nil {
+		return err
+	}
 	// s3backer requires two mounts
 	// first mount will fuse mount the bucket to a single 'file'
 	if err := s3backer.mountInit(stageTarget); err != nil {

pkg/s3/s3-driver_suite_test.go

@@ -121,6 +121,8 @@ var _ = Describe("S3Driver", func() {
 		if err := os.Remove(socket); err != nil && !os.IsNotExist(err) {
 			Expect(err).NotTo(HaveOccurred())
 		}
+		// Clear loop device so we cover the creation of it
+		os.Remove(s3.S3backerLoopDevice)
 		driver, err := s3.NewS3("test-node", csiEndpoint, cfg)
 		if err != nil {
 			log.Fatal(err)

pkg/s3/util.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"strings"
 	"syscall"
 	"time"
@@ -67,3 +68,20 @@ func getCmdLine(pid int) (string, error) {
 	}
 	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
+}