Print version string on startup from git describe

Makefile

@@ -1,4 +1,13 @@
-dev:
-	GOOS=linux GOARCH=arm64 go build .
+.PHONY: all build build_arm64 dev
+
+all: build
+
+build:
+	go build -ldflags="-X main.Version=`git describe --dirty`" .
+
+build_arm64:
+	GOOS=linux GOARCH=arm64 go build -ldflags="-X main.Version=`git describe --dirty`" .
+
+dev: build_arm64
 	scp godoor workshopdoor:/tmp/
 	ssh workshopdoor 'mv -f /tmp/godoor ~/ && sudo systemctl restart godoor'

godoor.go

@@ -12,6 +12,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"runtime/debug"
 	"strconv"
 	"strings"
 	"sync"
@@ -67,6 +68,20 @@ type OpenedTimestamp struct {
 	Closed *time.Time
 }
 
+var Commit = func() string {
+	if info, ok := debug.ReadBuildInfo(); ok {
+		for _, setting := range info.Settings {
+			if setting.Key == "vcs.revision" {
+				return setting.Value
+			}
+		}
+	}
+
+	return ""
+}()
+
+var Version string
+
 var config Config
 var globalLock sync.Mutex
 var validUids ValidUids
@@ -78,6 +93,7 @@ var openDoorTimestamps []OpenedTimestamp
 
 func main() {
 
+	log.Printf("GoDoor ver: %s (%s)", Version, Commit)
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer cancel()