build: add container for deployment

Author: BoxBoxJason

Containerfile

@@ -0,0 +1,21 @@
+FROM docker.io/golang:1.23.7-alpine AS build
+
+ARG GITLAB_SYNC_VERSION="dev"
+
+WORKDIR /app
+
+COPY go.mod .
+COPY ./cmd/ ./cmd/
+COPY ./mirroring/ ./mirroring/
+COPY ./utils/ ./utils/
+
+RUN go mod tidy && \
+    go build -ldflags "-X 'main.version=${GITLAB_SYNC_VERSION}'" -o /app/bin/gitlab-sync ./cmd/main.go
+
+FROM docker.io/alpine:latest
+
+RUN adduser -u 1000 -D -S gitlab-sync
+
+COPY --from=build --chown=gitlab-sync --chmod=550 /app/bin/gitlab-sync /usr/local/bin/gitlab-sync
+
+ENTRYPOINT [ "/usr/local/bin/gitlab-sync" ]