add backend dockerfile

api/Dockerfile

@@ -0,0 +1,24 @@
+FROM golang:1.19.0 as go-deps
+WORKDIR /src
+COPY go.mod .
+COPY go.sum .
+# 预下载依赖
+RUN go mod download
+
+# 开始第二个构建阶段，命名为 go-builder
+FROM golang:1.19.0 as go-builder
+WORKDIR /src
+# 被 go-deps 阶段预下载的依赖会存放在此
+COPY --from=go-deps /go/pkg/mod /go/pkg/mod
+COPY . .
+# 构建应用
+RUN go build -v -o app.out main.go && ls -al
+
+# 以 debian:stable-slim 作为基础镜像
+FROM debian:stable-slim
+WORKDIR /var/www/app
+# 从 go-builder 阶段拷贝构建产物
+COPY --from=go-builder /src/app.out /var/www/app/app
+
+# 设置容器启动时执行的命令
+CMD ["/var/www/app/app"]