Add bash command in restic package

Signed-off-by: Anisur Rahman <anisur@appscode.com>

pkg/restic/commands.go

@@ -37,6 +37,7 @@ import (
 
 const (
 	ResticCMD = "/bin/restic"
+	BashCMD   = "/bin/bash"
 )
 
 type Snapshot struct {
@@ -438,7 +439,7 @@ func (w *ResticWrapper) run(commands ...Command) ([]byte, error) {
 				return nil, err
 			}
 		}
-		w.sh.Command(cmd.Name, cmd.Args...)
+		w.sh.Command(BashCMD, "-c", cmd.getCommandAsString())
 	}
 	out, err := w.sh.Output()
 	if err != nil {
@@ -581,3 +582,11 @@ func (w *ResticWrapper) appendInsecureTLSFlag(args []interface{}) []interface{}
 	}
 	return args
 }
+
+func (c *Command) getCommandAsString() string {
+	cmdParts := []string{c.Name}
+	for _, arg := range c.Args {
+		cmdParts = append(cmdParts, fmt.Sprintf("%v", arg))
+	}
+	return strings.Join(cmdParts, " ")
+}