feat: add version flag

.github/workflows/build.yaml

@@ -75,4 +75,4 @@ jobs:
           go-version: ${{ env.GO_VERSION }}
       - uses: actions/checkout@v3
       - run: go mod vendor
-      - run: go build -mod=vendor -ldflags "-X 'main.Version=${{ github.event.base_ref }}' -extldflags '-static'" -o calendarsync cmd/calendarsync/main.go
+      - run: go build -mod=vendor -ldflags "-X 'main.Version=${{ github.ref_name }}' -extldflags '-static'" -o calendarsync cmd/calendarsync/main.go

.goreleaser.yaml

@@ -7,6 +7,8 @@ builds:
   - env:
       - CGO_ENABLED=0
     dir: ./cmd/calendarsync
+    ldflags:
+      - -X 'main.Version={{.Version}}'
     goos:
       - linux
       - windows

cmd/calendarsync/main.go

@@ -23,21 +23,20 @@ const (
 	flagClean                = "clean"
 	flagDryRun               = "dry-run"
 	flagPort                 = "port"
+	flagVersion              = "version"
 )
 
 var (
 	// The following vars are set during linking
 	// Version is the version from which the binary was built.
 	Version string
-	// BuildTime is the timestamp of building the binary.
-	BuildTime string
 )
 
 func main() {
 	app := &cli.App{
 		Name:        "CalendarSync",
 		Usage:       "Stateless calendar sync across providers",
-		Description: fmt.Sprintf("Version %s - Build date %s", Version, BuildTime),
+		Description: fmt.Sprintf("Version: %s", Version),
 		Flags: []cli.Flag{
 			&cli.StringFlag{
 				Name:  flagLogLevel,
@@ -49,9 +48,8 @@ func main() {
 				Value: "sync.yaml",
 			},
 			&cli.StringFlag{
-				Name:     flagStorageEncryptionKey,
-				Usage:    "encryption string",
-				Required: true,
+				Name:  flagStorageEncryptionKey,
+				Usage: "encryption string",
 			},
 			&cli.BoolFlag{
 				Name:  flagClean,
@@ -63,6 +61,11 @@ func main() {
 				Usage: "This flag helps you see which events would get created, updated or deleted without actually doing these operations",
 				Value: false,
 			},
+			&cli.BoolFlag{
+				Name:  flagVersion,
+				Usage: "shows the version of CalendarSync",
+				Value: false,
+			},
 			&cli.UintFlag{
 				Name:   flagPort,
 				Usage:  "set manual free port for the authentication process",
@@ -86,15 +89,25 @@ func main() {
 	if err := app.Run(os.Args); err != nil {
 		log.Fatal(err)
 	}
+
 }
 
 func Run(c *cli.Context) error {
+	if c.Bool(flagVersion) {
+		fmt.Println("Version:", Version)
+		os.Exit(0)
+	}
+
 	cfg, err := config.NewFromFile(c.String(flagConfigFilePath))
 	if err != nil {
 		return err
 	}
 	log.Info("loaded config file", "path", cfg.Path)
 
+	if len(c.String(flagStorageEncryptionKey)) == 0 {
+		return fmt.Errorf("flag --storage-encryption-key needs to be set")
+	}
+
 	startTime, err := models.TimeFromConfig(cfg.Sync.StartTime)
 	if err != nil {
 		return err