Refactor all mounters to use the mounter interface

pkg/s3/mounter.go

@@ -0,0 +1,34 @@
+package s3
+
+import "fmt"
+
+// Mounter interface which can be implemented
+// by the different mounter types
+type Mounter interface {
+	Format() error
+	Mount(targetPath string) error
+}
+
+const (
+	mounterKey        = "mounter"
+	s3fsMounterType   = "s3fs"
+	goofysMounterType = "goofys"
+	s3qlMounterType   = "s3ql"
+)
+
+// newMounter returns a new mounter depending on the mounterType parameter
+func newMounter(mounterType string, bucket string, cfg *Config) (Mounter, error) {
+	switch mounterType {
+	case "":
+	case s3fsMounterType:
+		return newS3fsMounter(bucket, cfg)
+
+	case goofysMounterType:
+		return newGoofysMounter(bucket, cfg)
+
+	case s3qlMounterType:
+		return newS3qlMounter(bucket, cfg)
+
+	}
+	return nil, fmt.Errorf("Error mounting bucket %s, invalid mounter specified: %s", bucket, mounterType)
+}