Add per-user locking option to portmaster-start run cmds

cmds/portmaster-start/lock.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"os/user"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -13,8 +14,22 @@ import (
 	processInfo "github.com/shirou/gopsutil/process"
 )
 
-func checkAndCreateInstanceLock(path, name string) (pid int32, err error) {
-	lockFilePath := filepath.Join(dataRoot.Path, path, fmt.Sprintf("%s-lock.pid", name))
+func checkAndCreateInstanceLock(path, name string, perUser bool) (pid int32, err error) {
+	var lockFilePath string
+	if perUser {
+		// Get user ID for per-user lock file.
+		var userID string
+		usr, err := user.Current()
+		if err != nil {
+			log.Printf("failed to get current user: %s\n", err)
+			userID = "no-user"
+		} else {
+			userID = usr.Uid
+		}
+		lockFilePath = filepath.Join(dataRoot.Path, path, fmt.Sprintf("%s-%s-lock.pid", name, userID))
+	} else {
+		lockFilePath = filepath.Join(dataRoot.Path, path, fmt.Sprintf("%s-lock.pid", name))
+	}
 
 	// read current pid file
 	data, err := ioutil.ReadFile(lockFilePath)