Improve service initialization and reloading

src/esvm/main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"crypto/sha256"
 	"flag"
 	"fmt"
 	"io"
@@ -15,8 +14,6 @@ import (
 	"strings"
 	"syscall"
 	"time"
-
-	"gopkg.in/yaml.v3"
 )
 
 // Build-time variables
@@ -136,64 +133,8 @@ func Init() {
 	// Read and initialize service files
 	for _, entry := range dirEntries {
 		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".esv") {
-			logger.Printf("Initializing service (%s)...\n", entry.Name())
+			filepath := path.Join(serviceConfigDir, "services", entry.Name())
-			bytes, err := os.ReadFile(path.Join(serviceConfigDir, "services", entry.Name()))
+			LoadService(filepath)
-			if err != nil {
-				logger.Printf("Error: Could not read service file (%s)", path.Join(serviceConfigDir, "services", entry.Name()))
-				continue
-			}
-
-			service := EnitService{
-				Name:             "",
-				Description:      "",
-				Type:             "",
-				StartCmd:         "",
-				ExitMethod:       "",
-				StopCmd:          "",
-				Restart:          "",
-				Setpgid:          true,
-				CrashOnSafeExit:  true,
-				LogOutput:        true,
-				Filepath:         path.Join(serviceConfigDir, "services", entry.Name()),
-				filepathChecksum: sha256.Sum256(bytes),
-				restartCount:     0,
-				stopChannel:      make(chan bool),
-				state:            EnitServiceUnloaded,
-			}
-			if err := yaml.Unmarshal(bytes, &service); err != nil {
-				logger.Printf("Error: could not read service file %s", path.Join(serviceConfigDir, "services", entry.Name()))
-				continue
-			}
-
-			for _, sv := range Services {
-				if sv.Name == service.Name {
-					logger.Printf("Error: service with name (%s) has already been initialized", service.Name)
-				}
-			}
-
-			switch service.Type {
-			case "simple", "background":
-			default:
-				logger.Printf("Error: unknown service type (%s)", service.Type)
-				continue
-			}
-
-			switch service.ExitMethod {
-			case "stop_command", "kill":
-			default:
-				logger.Printf("Error: unknown exit method (%s)\n", service.ExitMethod)
-				continue
-			}
-
-			switch service.Restart {
-			case "true", "always":
-			default:
-				service.Restart = "false"
-			}
-
-			Services = append(Services, &service)
-
-			logger.Printf("Service (%s) has been initialized!\n", service.Name)
 		}
 	}
 
@@ -231,8 +172,26 @@ func Init() {
 func Reload() {
 	logger.Println("Reloading all ESVM services...")
 
-	for _, service := range Services {
+	dirEntries, err := os.ReadDir(path.Join(serviceConfigDir, "services"))
-		service.ReloadService()
+	if err != nil {
+		logger.Fatalf("Error: Could not initialize ESVM: %s", err)
+	}
+
+	// Read and load service files
+	servicesToRemove := slices.Clone(Services)
+	for _, entry := range dirEntries {
+		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".esv") {
+			filepath := path.Join(serviceConfigDir, "services", entry.Name())
+			LoadService(filepath)
+			servicesToRemove = slices.DeleteFunc(servicesToRemove, func(sv *EnitService) bool {
+				return sv.Filepath == filepath
+			})
+		}
+	}
+
+	// Reload services that had their esv file removed
+	for _, service := range servicesToRemove {
+		LoadService(service.Filepath)
 	}
 
 	logger.Println("All ESVM services have been reloaded!")

src/esvm/service.go

@@ -101,9 +101,18 @@ func (service *EnitService) GetLogFile() (file *os.File, err error) {
 	return file, nil
 }
 
-func (service *EnitService) ReloadService() {
+func LoadService(filepath string) {
-	bytes, err := os.ReadFile(service.Filepath)
+	bytes, err := os.ReadFile(filepath)
 	checksum := sha256.Sum256(bytes)
+
+	var serviceToReload *EnitService
+
+	// Check if service is already loaded
+	for _, service := range Services {
+		if service.Filepath != filepath {
+			continue
+		}
+
 		if slices.Equal(checksum[:], service.filepathChecksum[:]) {
 			return
 		}
@@ -114,17 +123,29 @@ func (service *EnitService) ReloadService() {
 			return
 		}
 		service.shouldReload = false
+		serviceToReload = service
 
-	logger.Printf("Reloading service (%s)...\n", service.Filepath)
+		break
+	}
+
+	if serviceToReload == nil {
+		logger.Printf("Loading service (%s)...\n", filepath)
+	} else {
+		logger.Printf("Reloading service (%s)...\n", filepath)
+	}
 
 	if os.IsNotExist(err) {
 		Services = slices.DeleteFunc(Services, func(sv *EnitService) bool {
-			return sv == service
+			if sv.Filepath == filepath {
+				logger.Printf("Service (%s) has been removed\n", sv.Name)
+				return true
+			}
+			return false
 		})
-		logger.Printf("Service (%s) has been removed\n", service.Name)
+
 		return
 	} else if err != nil {
-		logger.Printf("Error: Could not read service file (%s)", service.Filepath)
+		logger.Printf("Error: Could not read service file (%s)", filepath)
 		return
 	}
 
@@ -139,20 +160,26 @@ func (service *EnitService) ReloadService() {
 		Setpgid:          true,
 		CrashOnSafeExit:  true,
 		LogOutput:        true,
-		Filepath:         service.Filepath,
+		Filepath:         filepath,
-		filepathChecksum: checksum,
+		filepathChecksum: sha256.Sum256(bytes),
-		restartCount:     service.restartCount,
+		restartCount:     0,
-		stopChannel:      service.stopChannel,
+		stopChannel:      make(chan bool),
-		state:            service.state,
+		state:            EnitServiceUnloaded,
+	}
+	if serviceToReload != nil {
+		newService.restartCount = serviceToReload.restartCount
+		newService.stopChannel = serviceToReload.stopChannel
+		newService.state = serviceToReload.state
 	}
 	if err := yaml.Unmarshal(bytes, &newService); err != nil {
-		logger.Printf("Error: could not read service file %s", service.Filepath)
+		logger.Printf("Error: could not read service file %s", filepath)
 		return
 	}
 
 	for _, sv := range Services {
-		if sv.Name == newService.Name && sv != service {
+		if sv.Name == newService.Name && sv != serviceToReload {
-			logger.Printf("Error: service with name (%s) has already been initialized", service.Name)
+			logger.Printf("Error: service with name (%s) has already been loaded", newService.Name)
+			return
 		}
 	}
 
@@ -177,12 +204,15 @@ func (service *EnitService) ReloadService() {
 	}
 
 	for i, sv := range Services {
-		if sv == service {
+		if sv == serviceToReload {
 			Services[i] = &newService
+			logger.Printf("Service (%s) has been reloaded!\n", newService.Name)
+			return
 		}
 	}
 
-	logger.Printf("Service (%s) has been reloaded!\n", newService.Name)
+	Services = append(Services, &newService)
+	logger.Printf("Service (%s) has been loaded!\n", newService.Name)
 }
 
 func (service *EnitService) StartService() (err error) {
@@ -294,7 +324,7 @@ func (service *EnitService) StartService() (err error) {
 
 					// Reload service if needed
 					if service.shouldReload {
-						service.ReloadService()
+						LoadService(service.Filepath)
 						if GetServiceByName(service.Name) == nil {
 							return
 						}
@@ -314,7 +344,7 @@ func (service *EnitService) StartService() (err error) {
 
 			// Reload service if needed
 			if service.shouldReload {
-				service.ReloadService()
+				LoadService(service.Filepath)
 				if GetServiceByName(service.Name) == nil {
 					return
 				}
@@ -362,7 +392,7 @@ func (service *EnitService) StopService() error {
 
 		// Reload service if needed
 		if service.shouldReload {
-			service.ReloadService()
+			LoadService(service.Filepath)
 			if GetServiceByName(service.Name) == nil {
 				return
 			}
@@ -422,6 +452,12 @@ func (service *EnitService) RestartService() error {
 		return err
 	}
 
+	// Get service from list in case of a reload
+	if GetServiceByName(service.Name) == nil {
+		return fmt.Errorf("service was removed")
+	}
+	service = GetServiceByName(service.Name)
+
 	if err := service.StartService(); err != nil {
 		return err
 	}