refactor(processor): replace error message formatting with errors.New for better error handling

README.md

@@ -0,0 +1,19 @@
+# Super-frpc Watchdog for GNU/Linux `systemd`
+
+## Basic Configuration
+
+Create a `config.json` file in the project root:
+
+```json
+{
+    "debugMode": false
+}
+```
+
+| Field | Description |
+| :---: | :---: |
+| `debugMode` | Debug mode status |
+
+## TODO
+
+- [x] Fix log trace eats too much disk io

errorHandle/processor.go

@@ -1,12 +1,13 @@
 package errorHandle
 
 import (
+	"errors"
 	"fmt"
 	"os/exec"
 	"time"
 
-	"Watchdog_Linux-systemd/postLog"
 	"Watchdog_Linux-systemd/global"
+	"Watchdog_Linux-systemd/postLog"
 )
 
 type ServiceStatusChecker func(serviceName string) bool
@@ -35,5 +36,5 @@ func HandleErrorProcess(serviceName string, isServiceRunning ServiceStatusChecke
 	serviceControl.ErrorType = "restart"
 	serviceControl.ErrorMsg = fmt.Sprintf("Failed to recover service '%s', retry count: %d", serviceName, serviceControl.RetryCount)
 	serviceControl.ErrorTime = time.Now()
-	return fmt.Errorf(serviceControl.ErrorMsg)
-}
+	return errors.New(serviceControl.ErrorMsg)
+}

monitor/monitor.go

@@ -2,8 +2,8 @@ package monitor
 
 import (
 	"Watchdog_Linux-systemd/errorHandle"
-	"Watchdog_Linux-systemd/postLog"
 	"Watchdog_Linux-systemd/global"
+	"Watchdog_Linux-systemd/postLog"
 	"Watchdog_Linux-systemd/socket"
 	"fmt"
 	"os/exec"
@@ -11,8 +11,6 @@ import (
 	"time"
 )
 
-
-
 func AddServiceMonitor(serviceName string) error {
 	global.MonitorsMutex.Lock()
 	defer global.MonitorsMutex.Unlock()
@@ -68,53 +66,74 @@ func runMonitor(m *global.ServiceMonitor) {
 			postLog.Info(fmt.Sprintf("[Monitor] Stopped monitoring service: %s", m.ServiceName))
 			return
 		case <-ticker.C:
-			serviceStatus, err := checkServiceStatus(m.ServiceName)
+			serviceStatus, statusDetail, err := checkServiceHealth(m.ServiceName)
 			if err != nil {
 				throwException(m.ServiceName, fmt.Sprintf("Failed to check service status: %v", err))
 				continue
 			}
 
-			logStatus, err := checkServiceLogs(m.ServiceName)
-			if err != nil {
-				throwException(m.ServiceName, fmt.Sprintf("Failed to check service logs: %v", err))
-				continue
-			}
-
-			if !serviceStatus || !logStatus {
-				throwException(m.ServiceName, fmt.Sprintf("Service check failed - Status: %v, Logs: %v", serviceStatus, logStatus))
+			if !serviceStatus {
+				throwException(m.ServiceName, fmt.Sprintf("Service check failed - %s", statusDetail))
 			}
 		}
 	}
 }
 
-func checkServiceStatus(serviceName string) (bool, error) {
-	cmd := exec.Command("systemctl", "is-active", serviceName)
+func checkServiceHealth(serviceName string) (bool, string, error) {
+	cmd := exec.Command(
+		"systemctl",
+		"show",
+		serviceName,
+		"--property=ActiveState",
+		"--property=SubState",
+		"--property=Result",
+		"--property=ExecMainStatus",
+		"--property=ExecMainCode",
+		"--property=NRestarts",
+	)
 	output, err := cmd.Output()
 	if err != nil {
-		return false, fmt.Errorf("failed to execute systemctl: %w", err)
+		return false, "", fmt.Errorf("failed to execute systemctl show: %w", err)
 	}
 
-	status := strings.TrimSpace(string(output))
-	return status == "active", nil
-}
-
-func checkServiceLogs(serviceName string) (bool, error) {
-	cmd := exec.Command("journalctl", "-u", serviceName, "-n", "50", "--no-pager")
-	output, err := cmd.Output()
-	if err != nil {
-		return false, fmt.Errorf("failed to execute journalctl: %w", err)
-	}
-
-	logContent := string(output)
-	errorKeywords := []string{"error", "fatal", "failed", "critical", "exception"}
-
-	for _, keyword := range errorKeywords {
-		if strings.Contains(strings.ToLower(logContent), keyword) {
-			return false, nil
+	properties := make(map[string]string)
+	for _, line := range strings.Split(strings.TrimSpace(string(output)), "\n") {
+		key, value, found := strings.Cut(line, "=")
+		if !found {
+			continue
 		}
+		properties[strings.TrimSpace(key)] = strings.TrimSpace(value)
 	}
 
-	return true, nil
+	if len(properties) == 0 {
+		return false, "", fmt.Errorf("unexpected systemctl show output: %q", strings.TrimSpace(string(output)))
+	}
+
+	activeState := properties["ActiveState"]
+	subState := properties["SubState"]
+	result := properties["Result"]
+	execMainStatus := properties["ExecMainStatus"]
+	execMainCode := properties["ExecMainCode"]
+	nRestarts := properties["NRestarts"]
+
+	detail := fmt.Sprintf("ActiveState=%s, SubState=%s, Result=%s, ExecMainStatus=%s, ExecMainCode=%s", activeState, subState, result, execMainStatus, execMainCode)
+	if nRestarts != "" {
+		detail = fmt.Sprintf("%s, NRestarts=%s", detail, nRestarts)
+	}
+
+	if activeState != "active" {
+		return false, detail, nil
+	}
+
+	if result != "" && result != "success" {
+		return false, detail, nil
+	}
+
+	if execMainStatus != "" && execMainStatus != "0" {
+		return false, detail, nil
+	}
+
+	return true, detail, nil
 }
 
 func IsServiceExist(serviceName string) bool {
@@ -126,15 +145,10 @@ func IsServiceExist(serviceName string) bool {
 }
 
 func IsServiceRunning(serviceName string) bool {
-	status, err := checkServiceStatus(serviceName)
+	status, _, err := checkServiceHealth(serviceName)
 	if err != nil || !status {
 		return false
 	}
-
-	logStatus, err := checkServiceLogs(serviceName)
-	if err != nil || !logStatus {
-		return false
-	}
 	return true
 }