feat: add version flag and embed build info in binary

.goreleaser.yaml

@@ -6,6 +6,10 @@ builds:
       - linux
       - windows
       - darwin
+    ldflags:
+      - -X main.BuildDate={{ .CommitDate }}
+      - -X main.Version={{ .Version }}
+      - -X main.Commit={{ .Commit }}
     binary: tagger
 dockers:
   # build latest and specific tag version images

tagger.go

@@ -24,6 +24,12 @@ import (
 	"golang.org/x/oauth2"
 )
 
+var (
+	Version   string // will be populated by linker during `go build`
+	BuildDate string // will be populated by linker during `go build`
+	Commit    string // will be populated by linker during `go build`
+)
+
 type objectTagMap map[string]map[int][]string
 type ReportMap map[string]map[string]ReportData
 
@@ -564,19 +570,33 @@ func init() {
 	})
 }
 
+func version() {
+	fmt.Printf("Tagger Build Information\nVersion: %s\nBuild Date: %s\nCommit: %s\n",
+		Version,
+		BuildDate,
+		Commit,
+	)
+}
+
 func main() {
 	// prep and parse flags
 	flag.String("config", "", "Path to configuration file to use")
 	flag.String("logging.level", "", "Logging level may be one of: trace, debug, info, warning, error, fatal and panic")
 	flag.Bool("dry-run", false, "Don't apply the tag changes")
 	flag.Bool("report", false, "Report output to summarize tag changes")
 	flag.Bool("json", false, "Provide changes in JSON")
+	flag.BoolP("version", "v", false, "Print version information about this build of tagger")
 
 	flag.Parse()
 	if err := viper.BindPFlags(flag.CommandLine); err != nil {
 		log.Fatal("Unable to bind flags")
 	}
 
+	if viper.GetBool("version") {
+		version()
+		os.Exit(0)
+	}
+
 	// get config
 	configFile := viper.GetString("config")
 	viper.SetConfigType("yaml")