feat: add versioning system

Dockerfile

@@ -1,5 +1,9 @@
 FROM golang:1.25.5-alpine AS go_builder
 
+ARG VERSION=dev
+ARG BUILD_DATE=unknown
+ARG COMMIT=unknown
+
 RUN apk update && apk upgrade && \
     apk add --no-cache ca-certificates tzdata git && \
     update-ca-certificates
@@ -18,7 +22,7 @@ RUN --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
     CGO_ENABLED=0 GOOS=linux \
     go build -trimpath \
-    -ldflags="-w -s" \
+    -ldflags="-w -s -X tunnel_pls/version.Version=${VERSION} -X tunnel_pls/version.BuildDate=${BUILD_DATE} -X tunnel_pls/version.Commit=${COMMIT}" \
     -o /app/tunnel_pls \
     .
 
@@ -28,6 +32,10 @@ RUN adduser -D -u 10001 -g '' appuser && \
 
 FROM scratch
 
+ARG VERSION=dev
+ARG BUILD_DATE=unknown
+ARG COMMIT=unknown
+
 COPY --from=go_builder /usr/share/zoneinfo /usr/share/zoneinfo
 COPY --from=go_builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=go_builder /etc/passwd /etc/passwd
@@ -43,6 +51,9 @@ ENV TZ=Asia/Jakarta
 EXPOSE 2200 8080 8443
 
 LABEL org.opencontainers.image.title="Tunnel Please" \
-      org.opencontainers.image.description="SSH-based tunnel server"
+      org.opencontainers.image.description="SSH-based tunnel server" \
+      org.opencontainers.image.version="${VERSION}" \
+      org.opencontainers.image.revision="${COMMIT}" \
+      org.opencontainers.image.created="${BUILD_DATE}"
 
 ENTRYPOINT ["/app/tunnel_pls"]