Merge pull request #7 from Kong/feat/version-command-and-handling

feat(build): add version metadata injection and display throughout the system

Author: sandromodarelli

.github/workflows/release.yml

@@ -46,7 +46,7 @@ jobs:
           BINARY_BASE="migrator_${VERSION}_${GOOS}_${GOARCH}"
 
           mkdir -p dist
-          go build -o "dist/${BINARY_BASE}" ./main.go
+          go build -ldflags="-X main.Version=${VERSION}" -o "dist/${BINARY_BASE}" ./main.go
 
           (cd dist && tar -czf "${BINARY_BASE}.tar.gz" "${BINARY_BASE}")
 
@@ -87,6 +87,7 @@ jobs:
           context: .
           platforms: linux/amd64,linux/arm64
           push: true
+          build-args: VERSION=${{ github.ref_name }}
           tags: |
             kong/nginx-kong-migrator:${{ github.ref_name }}
             kong/nginx-kong-migrator:latest

Dockerfile

@@ -3,7 +3,8 @@ WORKDIR /app
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -o /migrator .
+ARG VERSION=dev
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -ldflags="-X main.Version=${VERSION}" -o /migrator .
 
 FROM gcr.io/distroless/static-debian12:nonroot
 COPY --from=builder /migrator /migrator

main.go

@@ -12,15 +12,22 @@ import (
 	"nginx-kong-migrator/pkg/ui"
 )
 
+var Version = "dev"
+
 func main() {
+	if len(os.Args) > 1 && os.Args[1] == "version" {
+		fmt.Println(Version)
+		return
+	}
+
 	// ui subcommand — spins up the local dashboard server
 	if len(os.Args) > 1 && os.Args[1] == "ui" {
 		uiFlags := flag.NewFlagSet("ui", flag.ExitOnError)
 		port := uiFlags.Int("port", 8080, "Port to listen on")
 		namespace := uiFlags.String("namespace", "", "Kubernetes namespace to watch (empty = all namespaces)")
 		kubeconfig := uiFlags.String("kubeconfig", "", "Path to kubeconfig file (default: $KUBECONFIG or ~/.kube/config)")
 		uiFlags.Parse(os.Args[2:])
-		if err := ui.Start(*port, *namespace, *kubeconfig); err != nil {
+		if err := ui.Start(*port, *namespace, *kubeconfig, Version); err != nil {
 			log.Fatalf("ui server error: %v", err)
 		}
 		return

pkg/ui/server.go

@@ -34,6 +34,7 @@ var templateFS embed.FS
 
 type srv struct {
 	namespace string
+	version   string
 	client    kubernetes.Interface
 	dynClient dynamic.Interface
 }
@@ -52,7 +53,7 @@ var (
 )
 
 // Start builds Kubernetes clients and starts the HTTP server on the given port.
-func Start(port int, namespace string, kubeconfig string) error {
+func Start(port int, namespace string, kubeconfig string, version string) error {
 	config, err := buildConfig(kubeconfig)
 	if err != nil {
 		return fmt.Errorf("failed to build kubeconfig: %w", err)
@@ -68,7 +69,7 @@ func Start(port int, namespace string, kubeconfig string) error {
 		return fmt.Errorf("failed to create dynamic client: %w", err)
 	}
 
-	s := &srv{namespace: namespace, client: client, dynClient: dynClient}
+	s := &srv{namespace: namespace, version: version, client: client, dynClient: dynClient}
 
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handleIndex)
@@ -119,8 +120,9 @@ func (s *srv) handleIndex(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "template not found", http.StatusInternalServerError)
 		return
 	}
+	content := strings.ReplaceAll(string(data), "__APP_VERSION__", s.version)
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	w.Write(data)
+	w.Write([]byte(content))
 }
 
 func (s *srv) handleIngresses(w http.ResponseWriter, r *http.Request) {

pkg/ui/templates/index.html

@@ -107,7 +107,7 @@
 
   <div class="mt-auto px-4 py-4 border-t border-sidebar-border text-xs text-sidebar-section">
     <span class="block mb-0.5 text-sidebar-text font-medium">NGINX → Kong Migrator</span>
-    v0.1.0
+    __APP_VERSION__
   </div>
 </aside>