加快drone ci中docker构建速度

.drone.yml

---
kind: pipeline
type: kubernetes
name: some-pipeline

steps:
  - name: build_cache
    image: plugins/docker
    settings:
      registry: some-registry.com
      repo: some-registry.com/some-project/some-image
      cache_from:
        - some-registry.com/some-project/some-image:builder
      tags:
        - builder
      target: builder
      auto_label: false
      username:
        from_secret: DOCKER_USERNAME
      password:
        from_secret: DOCKER_PASSWORD
      dockerfile: Dockerfile

  - name: build_final
    image: plugins/docker
    settings:
      registry: some-registry.com
      repo: some-registry.com/some-project/some-image
      cache_from:
        - some-registry.com/some-project/some-image:builder
        - some-registry.com/some-project/some-image:latest
      tags:
        - latest
        - ${DRONE_TAG:-0.0.0}-${DRONE_COMMIT_SHA:0:7}
      auto_label: false
      username:
        from_secret: DOCKER_USERNAME
      password:
        from_secret: DOCKER_PASSWORD
      dockerfile: Dockerfile

README.md

说明

1. 在Dockerfile的构建步骤中，将相对变化较小的步骤提前。
2. 在go build之前先copy go.mod和go.sum并下载依赖。
3. 在drone.yml中，先用build_cache步骤，构建builder阶段并且push为some-image:builder
4. 在build_cache和build_final步骤中，使用cache_from指定some-image:builder作为构建缓存
5. 如果在build_final阶段存在一些耗时的安装依赖等步骤，可以追加some-image:latest构建缓存，否则可以忽略
6. 不知为何，在k8s的drone上跑plugins/docker时，默认自动的4个oci label的步骤会特别耗时，如果没有特别需要，使用auto_label = false配置项以关闭该行为

Dockerfile

FROM golang:1.24-alpine AS builder

ENV GO111MODULE=on \
    GOPROXY=https://goproxy.cn,direct \
    GOPRIVATE=github.com/bytemind-io

WORKDIR /app

RUN apk add git openssh

COPY go.* ./
RUN go mod download

COPY . .
RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o some-app ./main.go


FROM alpine:latest

WORKDIR /app

RUN apk add some-dependency

COPY --from=builder /app/some-app .

ENTRYPOINT ["/app/some-app"]