add experimental plugin system

sdk/plugin/util.go

@@ -0,0 +1,25 @@
+package plugin
+
+import (
+	"github.com/shirou/gopsutil/v3/process"
+
+	"github.com/drakkan/sftpgo/v2/logger"
+)
+
+func killProcess(processPath string) {
+	procs, err := process.Processes()
+	if err != nil {
+		return
+	}
+	for _, p := range procs {
+		cmdLine, err := p.Exe()
+		if err == nil {
+			if cmdLine == processPath {
+				err = p.Kill()
+				logger.Debug(logSender, "", "killed process %v, pid %v, err %v", cmdLine, p.Pid, err)
+				return
+			}
+		}
+	}
+	logger.Debug(logSender, "", "no match for plugin process %v", processPath)
+}