Rename some functions. Add functionality needed in main.go to install/upgrade/uninstal/etc the run command service

main/cmds.go

@@ -86,16 +86,45 @@ var (
 	ExitCode_RunAsLookupUserUidFailed                     = -212
 	ExitCode_RunAsScriptFileChangeOwnerFailed             = -213
 	ExitCode_RunAsScriptFileChangePermissionsFailed       = -214
+	ExitCode_CheckDataDirectoryFailed                     = -215
+	ExitCode_UpgradeInstalledServiceFailed                = -216
+	ExitCode_InstallServiceFailed                         = -217
+	ExitCode_UninstallInstalledServiceFailed              = -218
+	ExitCode_DisableInstalledServiceFailed                = -219
 
 	// Unknown errors (-300s):
 )
 
 func update(ctx *log.Context, h HandlerEnvironment, report *RunCommandInstanceView, extName string, seqNum int) (string, string, error, int) {
+	isInstalled, err := RunCommandServiceIsInstalled(ctx)
+	if err != nil {
+		return "", "", errors.Wrap(err, "failed to check if runcommand service is installed"), ExitCode_CheckDataDirectoryFailed
+	}
+
+	if isInstalled {
+		_, error := UpgradeRunCommandService(ctx)
+		if error != nil {
+			return "", "", errors.Wrap(err, "failed to upgrade run command service"), ExitCode_UpgradeInstalledServiceFailed
+		}
+	}
+
 	ctx.Log("event", "update")
 	return "", "", nil, ExitCode_Okay
 }
 
 func disable(ctx *log.Context, h HandlerEnvironment, report *RunCommandInstanceView, extName string, seqNum int) (string, string, error, int) {
+	isInstalled, err := RunCommandServiceIsInstalled(ctx)
+	if err != nil {
+		return "", "", errors.Wrap(err, "failed to check if runcommand service is installed"), ExitCode_CheckDataDirectoryFailed
+	}
+
+	if isInstalled {
+		_, error := stopService(ctx)
+		if error != nil {
+			return "", "", errors.Wrap(err, "failed to stop run command service"), ExitCode_DisableInstalledServiceFailed
+		}
+	}
+
 	ctx.Log("event", "disable")
 	KillPreviousExtension(ctx, pidFilePath)
 	return "", "", nil, ExitCode_Okay
@@ -112,6 +141,18 @@ func install(ctx *log.Context, h HandlerEnvironment, report *RunCommandInstanceV
 }
 
 func uninstall(ctx *log.Context, h HandlerEnvironment, report *RunCommandInstanceView, extName string, seqNum int) (string, string, error, int) {
+	isInstalled, err := RunCommandServiceIsInstalled(ctx)
+	if err != nil {
+		return "", "", errors.Wrap(err, "failed to check if runcommand service is installed"), ExitCode_CheckDataDirectoryFailed
+	}
+
+	if isInstalled {
+		_, error := UninstallRunCommandService(ctx)
+		if error != nil {
+			return "", "", errors.Wrap(err, "failed to uninstall run command service"), ExitCode_UninstallInstalledServiceFailed
+		}
+	}
+
 	{ // a new context scope with path
 		ctx = ctx.With("path", dataDir)
 		ctx.Log("event", "removing data dir", "path", dataDir)
@@ -151,6 +192,18 @@ func enable(ctx *log.Context, h HandlerEnvironment, report *RunCommandInstanceVi
 		return "", "", errors.Wrap(err, "failed to get configuration"), ExitCode_GetHandlerSettingsFailed
 	}
 
+	// If installService was provided and is equals to true, then install RunCommand as a service
+	if cfg.installAsService() {
+		serviceWasInstalled, err1 := InstallRunCommandService(ctx)
+		if err1 != nil {
+			return "", "", errors.Wrap(err1, "failed to install RunCommand as a service"), ExitCode_InstallServiceFailed
+		}
+
+		if serviceWasInstalled {
+			ctx.Log("message", "RunCommand service successfully installed")
+		}
+	}
+
 	dir := filepath.Join(dataDir, downloadDir, fmt.Sprintf("%d", seqNum))
 	scriptFilePath, err := downloadScript(ctx, dir, &cfg)
 	if err != nil {

main/handlersettings.go

@@ -17,6 +17,11 @@ type handlerSettings struct {
 	protectedSettings
 }
 
+// Gets the InstallAsService field from the RunCommand's properties
+func (s handlerSettings) installAsService() bool {
+	return s.publicSettings.Source.InstallAsService
+}
+
 func (s handlerSettings) script() string {
 	return s.publicSettings.Source.Script
 }

main/serviceinstall.go

@@ -27,11 +27,14 @@ const (
 
 	// The name of the systemd configuration file
 	systemdServiceName = "managed-run-command.service"
+
+	// The full path of the systemd configuration for the RunCommand service
+	systemServiceFilePath = "/lib/systemd/system/" + systemdServiceName
 )
 
 // Installs RunCommand as a service on the client
-func InstallService(ctx *log.Context) (bool, error) {
-	_, err := updateRunCommandVersion(ctx)
+func InstallRunCommandService(ctx *log.Context) (bool, error) {
+	_, err := createOrUpdateRunCommandService(ctx)
 	if err != nil {
 		return false, errors.Wrap(err, "failed to install service")
 	}
@@ -39,9 +42,9 @@ func InstallService(ctx *log.Context) (bool, error) {
 	return startService(ctx)
 }
 
-// Upgrades the RunCommand service with the latest available one
-func UpgradeService(ctx *log.Context) (bool, error) {
-	_, err := updateRunCommandVersion(ctx)
+// Upgrades the RunCommand service with the latest available one (if any service exists)
+func UpgradeRunCommandService(ctx *log.Context) (bool, error) {
+	_, err := createOrUpdateRunCommandService(ctx)
 	if err != nil {
 		return false, errors.Wrap(err, "failed to upgrade service")
 	}
@@ -55,13 +58,13 @@ func UpgradeService(ctx *log.Context) (bool, error) {
 }
 
 // Stops and removes the installed service from the VM.
-func RemoveService(ctx *log.Context) (bool, error) {
+func UninstallRunCommandService(ctx *log.Context) (bool, error) {
 	_, err := stopService(ctx)
 	if err != nil {
 		return false, errors.Wrap(err, "failed to remove service")
 	}
 
-	err = os.Remove("/lib/systemd/system/" + systemdServiceName)
+	err = os.Remove(systemServiceFilePath)
 	if err != nil {
 		return false, errors.Wrap(err, "failed to delete systemd configuration")
 	}
@@ -69,11 +72,26 @@ func RemoveService(ctx *log.Context) (bool, error) {
 	return true, nil
 }
 
+// Checks if the service is installed by checking for the presence of the systemd configuration file
+func RunCommandServiceIsInstalled(ctx *log.Context) (bool, error) {
+	_, err := os.Stat(systemServiceFilePath)
+
+	if errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	}
+
+	if err != nil {
+		return false, errors.Wrap(err, "failed to check if systemd configuration file exists")
+	}
+
+	return true, nil
+}
+
 // Updates the version of RunCommand to execute.
 // It will update the 'WorkingDirectory' and 'ExecStart' paths of the systemd configuration.
 // If this is the first time the method is getting invoked, then it will create the config file with the required details.
 // Subsequent calls will update the version of RunCommand to use.
-func updateRunCommandVersion(ctx *log.Context) (bool, error) {
+func createOrUpdateRunCommandService(ctx *log.Context) (bool, error) {
 	runCommandVersion := "2.42.0"
 	systemdConfig := fmt.Sprintf(serviceDetails, runCommandVersion)
 	err := os.WriteFile("/lib/systemd/system/"+systemdServiceName, []byte(systemdConfig), 0666)