LXC container support without LXD (#552)

* LXC container support without LXD

* Fix: LXC required root privilege

* Update README

scan/base.go

@@ -110,6 +110,12 @@ func (l *base) allContainers() (containers []config.Container, err error) {
 			return containers, err
 		}
 		return l.parseLxdPs(stdout)
+	case "lxc":
+		stdout, err := l.lxcPs("-1")
+		if err != nil {
+			return containers, err
+		}
+		return l.parseLxcPs(stdout)
 	default:
 		return containers, fmt.Errorf(
 			"Not supported yet: %s", l.ServerInfo.Containers.Type)
@@ -130,6 +136,12 @@ func (l *base) runningContainers() (containers []config.Container, err error) {
 			return containers, err
 		}
 		return l.parseLxdPs(stdout)
+	case "lxc":
+		stdout, err := l.lxcPs("-1 --running")
+		if err != nil {
+			return containers, err
+		}
+		return l.parseLxcPs(stdout)
 	default:
 		return containers, fmt.Errorf(
 			"Not supported yet: %s", l.ServerInfo.Containers.Type)
@@ -150,6 +162,12 @@ func (l *base) exitedContainers() (containers []config.Container, err error) {
 			return containers, err
 		}
 		return l.parseLxdPs(stdout)
+	case "lxc":
+		stdout, err := l.lxcPs("-1 --stopped")
+		if err != nil {
+			return containers, err
+		}
+		return l.parseLxcPs(stdout)
 	default:
 		return containers, fmt.Errorf(
 			"Not supported yet: %s", l.ServerInfo.Containers.Type)
@@ -174,6 +192,15 @@ func (l *base) lxdPs(option string) (string, error) {
 	return r.Stdout, nil
 }
 
+func (l *base) lxcPs(option string) (string, error) {
+	cmd := fmt.Sprintf("lxc-ls %s 2>/dev/null", option)
+	r := l.exec(cmd, sudo)
+	if !r.isSuccess() {
+		return "", fmt.Errorf("failed to SSH: %s", r)
+	}
+	return r.Stdout, nil
+}
+
 func (l *base) parseDockerPs(stdout string) (containers []config.Container, err error) {
 	lines := strings.Split(stdout, "\n")
 	for _, line := range lines {
@@ -214,6 +241,21 @@ func (l *base) parseLxdPs(stdout string) (containers []config.Container, err err
 	return
 }
 
+func (l *base) parseLxcPs(stdout string) (containers []config.Container, err error) {
+	lines := strings.Split(stdout, "\n")
+	for _, line := range lines {
+		fields := strings.Fields(line)
+		if len(fields) == 0 {
+			break
+		}
+		containers = append(containers, config.Container{
+			ContainerID: fields[0],
+			Name:        fields[0],
+		})
+	}
+	return
+}
+
 func (l *base) detectPlatform() {
 	ok, instanceID, err := l.detectRunningOnAws()
 	if err != nil {