Feature/notifications

README.md

@@ -49,6 +49,9 @@ yay -S fan2go-git
 Download the latest release from GitHub:
 
 ```shell
+# Install dependencies
+sudo pacman -S libnotify
+
 curl -L -o fan2go https://github.com/markusressel/fan2go/releases/latest/download/fan2go-linux-amd64
 chmod +x fan2go
 sudo cp ./fan2go /usr/bin/fan2go

cmd/root.go

@@ -38,7 +38,8 @@ on your computer based on temperature sensors.`,
 		configuration.LoadConfig()
 		err := configuration.Validate(configPath)
 		if err != nil {
-			ui.Fatal(err.Error())
+			ui.ErrorAndNotify("Config Validation Error", err.Error())
+			return
 		}
 
 		internal.RunDaemon()

internal/backend.go

@@ -64,7 +64,7 @@ func RunDaemon() {
 
 				go func() {
 					if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-						ui.Error("Cannot start prometheus metrics endpoint (%s)", err.Error())
+						ui.ErrorAndNotify("Statistics Error", "Cannot start prometheus metrics endpoint (%s)", err.Error())
 					}
 				}()
 
@@ -114,12 +114,13 @@ func RunDaemon() {
 				err := fanController.Run(ctx)
 				ui.Info("Fan controller for fan %s stopped.", fan.GetId())
 				if err != nil {
+					ui.NotifyError(fmt.Sprintf("Fan Controller: %s", fan.GetId()), err.Error())
 					panic(err)
 				}
 				return err
 			}, func(err error) {
 				if err != nil {
-					ui.Warning("Something went wrong: %v", err)
+					ui.WarningAndNotify(fmt.Sprintf("Fan Controller: %s", fan.GetId()), "Something went wrong: %v", err)
 				}
 			})
 		}

internal/configuration/config.go

@@ -42,7 +42,7 @@ func InitConfig(cfgFile string) {
 		// Find home directory.
 		home, err := homedir.Dir()
 		if err != nil {
-			ui.Error("Couldn't detect home directory: %v", err)
+			ui.ErrorAndNotify("Path Error", "Couldn't detect home directory: %v", err)
 			os.Exit(1)
 		}
 

internal/controller/controller.go

@@ -146,7 +146,7 @@ func (f *fanController) Run(ctx context.Context) error {
 				case <-tick:
 					err = f.UpdateFanSpeed()
 					if err != nil {
-						ui.Error("Error in FanController for fan %s: %v", fan.GetId(), err)
+						ui.ErrorAndNotify("Fan Control Error", "Fan %s: %v", fan.GetId(), err)
 						f.restorePwmEnabled()
 						return nil
 					}

internal/persistence/persistence.go

@@ -34,7 +34,7 @@ func NewPersistence(dbPath string) Persistence {
 func (p persistence) openPersistence() *bolt.DB {
 	db, err := bolt.Open(p.dbPath, 0600, &bolt.Options{Timeout: 1 * time.Minute})
 	if err != nil {
-		ui.Error("Could not open database file: %v", err)
+		ui.ErrorAndNotify("Persistence Error", "Could not open database file: %v", err)
 		os.Exit(1)
 	}
 	return db

internal/ui/logging.go

@@ -1,6 +1,7 @@
 package ui
 
 import (
+	"fmt"
 	"github.com/pterm/pterm"
 )
 
@@ -32,10 +33,21 @@ func Warning(format string, a ...interface{}) {
 	pterm.Warning.Printfln(format, a...)
 }
 
+func WarningAndNotify(title string, format string, a ...interface{}) {
+	Error(format, a...)
+	NotifyError(title, fmt.Sprintf(format, a...))
+}
+
 func Error(format string, a ...interface{}) {
 	pterm.Error.Printfln(format, a...)
 }
 
+func ErrorAndNotify(title string, format string, a ...interface{}) {
+	Error(format, a...)
+	NotifyError(title, fmt.Sprintf(format, a...))
+}
+
 func Fatal(format string, a ...interface{}) {
+	NotifyError("Fatal Error", fmt.Sprintf(format, a...))
 	pterm.Fatal.Printfln(format, a...)
 }

internal/ui/notification.go

@@ -0,0 +1,80 @@
+package ui
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+)
+
+// For a list of possible icons, see: https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
+const (
+	IconDialogError = "dialog-error"
+	IconDialogInfo  = "dialog-information"
+	IconDialogWarn  = "dialog-warning"
+
+	UrgencyLow      = "low"
+	UrgencyNormal   = "normal"
+	UrgencyCritical = "critical"
+)
+
+func NotifyInfo(title, text string) {
+	NotifySend(UrgencyLow, title, text, IconDialogInfo)
+}
+
+func NotifyWarn(title, text string) {
+	NotifySend(UrgencyNormal, title, text, IconDialogWarn)
+}
+
+func NotifyError(title, text string) {
+	NotifySend(UrgencyCritical, title, text, IconDialogError)
+}
+
+func NotifySend(urgency, title, text, icon string) {
+	display, exists := os.LookupEnv("DISPLAY")
+	if !exists {
+		Warning("Cannot send notification, missing env variable 'DISPLAY'!")
+		return
+	}
+
+	cmd := exec.Command("who")
+	output, err := cmd.Output()
+	if err != nil {
+		Warning("Cannot send notification, unable to find user of display session: %v", err)
+		return
+	}
+	lines := strings.Split(string(output), "\n")
+	var user string
+	for _, line := range lines {
+		if strings.Contains(line, display) {
+			user = strings.TrimSpace(strings.Fields(line)[0])
+			break
+		}
+	}
+
+	if len(user) <= 0 {
+		Warning("Cannot send notification, unable to detect user of current display session")
+		return
+	}
+
+	cmd = exec.Command("id", "-u", user)
+	output, err = cmd.Output()
+	userIdString := strings.TrimSpace(string(output))
+	if len(userIdString) <= 0 {
+		Warning("Cannot send notification, unable to detect user id")
+		return
+	}
+
+	cmd = exec.Command("sudo", "-u", user,
+		"DISPLAY="+display,
+		"DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/"+userIdString+"/bus",
+		"notify-send",
+		"-a", "fan2go",
+		"-u", urgency,
+		"-i", icon,
+		title, text,
+	)
+	err = cmd.Run()
+	if err != nil {
+		Error("Error sending notification: %v", err)
+	}
+}