Remove redundant 'exit_method' field

services/lo-interface.esv

@@ -1,7 +1,6 @@
 name: lo-interface
 description: Enable loopback interface on boot
-dependencies: ["/usr/sbin/ip"]
 type: simple
 start_cmd: ip link set lo up
 exit_method: kill
-restart: false
+restart: false

src/esvm/service.go

@@ -6,8 +6,10 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"os/user"
 	"path"
 	"slices"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -42,9 +44,9 @@ type EnitService struct {
 	Description      string `yaml:"description,omitempty"`
 	Type             string `yaml:"type"`
 	StartCmd         string `yaml:"start_cmd"`
-	ExitMethod       string `yaml:"exit_method"`
 	CrashOnSafeExit  bool   `yaml:"crash_on_safe_exit"`
 	StopCmd          string `yaml:"stop_cmd,omitempty"`
+	User             string `yaml:"user,omitempty"`
 	Restart          string `yaml:"restart,omitempty"`
 	ReadyFd          int    `yaml:"ready_fd"`
 	Setpgid          bool   `yaml:"setpgid"`
@@ -154,8 +156,8 @@ func LoadService(filepath string) {
 		Description:      "",
 		Type:             "",
 		StartCmd:         "",
-		ExitMethod:       "",
 		StopCmd:          "",
+		User:             "",
 		Restart:          "",
 		Setpgid:          true,
 		CrashOnSafeExit:  true,
@@ -190,13 +192,6 @@ func LoadService(filepath string) {
 		return
 	}
 
-	switch newService.ExitMethod {
-	case "stop_command", "kill":
-	default:
-		logger.Printf("Error: unknown exit method (%s)\n", newService.ExitMethod)
-		return
-	}
-
 	switch newService.Restart {
 	case "true", "always":
 	default:
@@ -236,10 +231,38 @@ func (service *EnitService) StartService() (err error) {
 
 	cmd := exec.Command("/bin/sh", "-c", "exec "+service.StartCmd)
 	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: service.Setpgid, Pgid: 0}
+
+	// Setup service log file
 	if logFile != nil {
 		cmd.Stdout = logFile
 		cmd.Stderr = logFile
 	}
+
+	// Setup command credentials
+	if service.User != "" && service.User != "root" {
+		// Lookup user in /etc/passwd
+		u, err := user.Lookup(service.User)
+		if err != nil {
+			return err
+		}
+
+		// Get user id and group id
+		uid, err := strconv.Atoi(u.Uid)
+		if err != nil {
+			return err
+		}
+		gid, err := strconv.Atoi(u.Gid)
+		if err != nil {
+			return err
+		}
+
+		cmd.SysProcAttr.Credential = &syscall.Credential{
+			Uid: uint32(uid),
+			Gid: uint32(gid),
+		}
+	}
+
+	// Setup command pipes
 	var pipeReader, pipeWriter *os.File
 	if service.ReadyFd > 2 {
 		pipeReader, pipeWriter, err = os.Pipe()
@@ -267,6 +290,7 @@ func (service *EnitService) StartService() (err error) {
 		}
 		cmd.ExtraFiles = append(cmd.ExtraFiles, pipeWriter)
 	}
+
 	if err := cmd.Start(); err != nil {
 		// Close log file if not nil
 		if logFile != nil {
@@ -319,7 +343,7 @@ func (service *EnitService) StartService() (err error) {
 
 			if service.Type == "simple" && err == nil {
 				service.restartCount = 0
-				if service.ExitMethod != "stop_command" {
+				if strings.TrimSpace(service.StopCmd) == "" {
 					service.state = EnitServiceCompleted
 
 					// Reload service if needed
@@ -395,7 +419,7 @@ func (service *EnitService) StopService() error {
 		}
 	}()
 
-	if service.ExitMethod == "kill" {
+	if strings.TrimSpace(service.StopCmd) == "" {
 		if err := service.GetProcess().Signal(syscall.Signal(0)); err != nil {
 			newServiceStatus = EnitServiceStopped
 			logger.Printf("Service (%s) has stopped (Process already dead)", service.Name)
@@ -413,6 +437,31 @@ func (service *EnitService) StopService() error {
 		go func() { service.stopChannel <- true }()
 
 		cmd := exec.Command("/bin/sh", "-c", service.StopCmd)
+
+		// Setup command credentials
+		if service.User != "" && service.User != "root" {
+			// Lookup user in /etc/passwd
+			u, err := user.Lookup(service.User)
+			if err != nil {
+				return err
+			}
+
+			// Get user id and group id
+			uid, err := strconv.Atoi(u.Uid)
+			if err != nil {
+				return err
+			}
+			gid, err := strconv.Atoi(u.Gid)
+			if err != nil {
+				return err
+			}
+
+			cmd.SysProcAttr.Credential = &syscall.Credential{
+				Uid: uint32(uid),
+				Gid: uint32(gid),
+			}
+		}
+
 		if err := cmd.Run(); err != nil {
 			return err
 		}