chore(signal): Adding signal for the crio/containerd runtime (#306)

Signed-off-by: shubhamchaudhary <shubham@chaosnative.com>

chaoslib/litmus/container-kill/helper/container-kill.go

@@ -89,7 +89,7 @@ func KillContainer(experimentsDetails *experimentTypes.ExperimentDetails, client
 				return err
 			}
 		case "containerd", "crio":
-			if err := StopContainerdContainer(containerID, experimentsDetails.SocketPath); err != nil {
+			if err := StopContainerdContainer(containerID, experimentsDetails.SocketPath, experimentsDetails.Signal); err != nil {
 				return err
 			}
 		default:
@@ -152,10 +152,18 @@ func GetContainerID(experimentsDetails *experimentTypes.ExperimentDetails, clien
 }
 
 //StopContainerdContainer kill the application container
-func StopContainerdContainer(containerID, socketPath string) error {
+func StopContainerdContainer(containerID, socketPath, signal string) error {
 	var errOut bytes.Buffer
+	var cmd *exec.Cmd
 	endpoint := "unix://" + socketPath
-	cmd := exec.Command("crictl", "-i", endpoint, "-r", endpoint, "stop", string(containerID))
+	switch signal {
+	case "SIGKILL":
+		cmd = exec.Command("crictl", "-i", endpoint, "-r", endpoint, "stop", "--timeout=0", string(containerID))
+	case "SIGTERM":
+		cmd = exec.Command("crictl", "-i", endpoint, "-r", endpoint, "stop", string(containerID))
+	default:
+		return errors.Errorf("{%v} signal not supported, use either SIGTERM or SIGKILL", signal)
+	}
 	cmd.Stderr = &errOut
 	if err := cmd.Run(); err != nil {
 		return errors.Errorf("Unable to run command, err: %v; error output: %v", err, errOut.String())