SRE文档

深浅模式

1.Docker 镜像的大小减少 ​

1.1基本dockerfile ​

276MB

bash
FROM golang:1.23.1-alpine
WORKDIR /app
COPY go.* ./
RUN go mod download
COPY . .
RUN go build -o main .
CMD ["./main"]
FROM golang:1.23.1-alpine
WORKDIR /app
COPY go.* ./
RUN go mod download
COPY . .
RUN go build -o main .
CMD ["./main"]

1.2 多阶段镜像 ​

通过使用多阶段映像，我们可以分离编译和执行阶段，这有助于从最终映像中排除不必要的文件（如 Go 构建工具）

bash
FROM golang:1.23.1-alpine AS builder
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN go build -o main .
FROM golang:1.23.1-alpine
COPY --from=builder /app /
CMD ["./main"]
FROM golang:1.23.1-alpine AS builder
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN go build -o main .
FROM golang:1.23.1-alpine
COPY --from=builder /app /
CMD ["./main"]

优化 ​

我们优化构建阶段以生成更轻量的二进制文件

CGO_ENABLED=0：禁用对 C 库的依赖，允许我们创建静态二进制文件。

GOARCH=amd64 和 GOOS=linux：指定我们正在为 Linux amd64 架构构建。

scratch：使用临时映像，即一个不包含任何内容（没有操作系统，没有库）的空镜像，这可以通过静态二进制文件实现。

bash
FROM golang:1.23.1-alpine AS builder
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o main -a --trimpath --ldflags="-s -w" --installsuffix cgo
FROM scratch
COPY --from=builder /app /
CMD ["./main"]
FROM golang:1.23.1-alpine AS builder
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o main -a --trimpath --ldflags="-s -w" --installsuffix cgo
FROM scratch
COPY --from=builder /app /
CMD ["./main"]

1.3 用UPX进行二进制压缩 ​

对二进制进行压缩

bash
FROM golang:1.23.1-alpine AS builder
RUN apk add --no-cache upx
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o main -a --trimpath --ldflags="-s -w" --installsuffix cgo
RUN upx --ultra-brute -qq main && upx --t main
FROM scratch
COPY --from=builder /app /
CMD ["./main"]
FROM golang:1.23.1-alpine AS builder
RUN apk add --no-cache upx
WORKDIR /app
COPY go.* ./
RUN go mod download && go mod verify
COPY . .
RUN CGO_ENABLED=0 GOARCH=amd64 GOOS=linux go build -o main -a --trimpath --ldflags="-s -w" --installsuffix cgo
RUN upx --ultra-brute -qq main && upx --t main
FROM scratch
COPY --from=builder /app /
CMD ["./main"]