增加go的镜像加速

backend/Dockerfile

@@ -1,10 +1,19 @@
+# syntax=docker/dockerfile:1.7
+
 FROM golang:1.26-alpine AS build
 
 WORKDIR /src
+ARG GOPROXY=https://goproxy.cn,direct
+ARG GOSUMDB=sum.golang.google.cn
+ENV GOPROXY=${GOPROXY} \
+    GOSUMDB=${GOSUMDB}
+
 COPY go.mod go.sum* ./
-RUN go mod download
+RUN --mount=type=cache,target=/go/pkg/mod go mod download
 COPY . .
-RUN CGO_ENABLED=0 GOOS=linux go build -o /out/hfb-api ./cmd/api
+RUN --mount=type=cache,target=/go/pkg/mod \
+    --mount=type=cache,target=/root/.cache/go-build \
+    CGO_ENABLED=0 GOOS=linux go build -o /out/hfb-api ./cmd/api
 
 FROM alpine:3.22