我有一个由 Yarn 管理的 monorepo，我想利用 Docker 缓存层来加速我的构建，为此我想首先复制
package.jsonyarn.lockyarn install 这是我的回购结构：
packages/one/package.json
packages/one/index.js
packages/two/package.json
packages/two/index.js
package.json
yarn.lock
这是 Dockerfile 中令人感兴趣的部分：
COPY package.json .
COPY yarn.lock .
COPY packages/**/package.json ./
RUN yarn install --pure-lockfile
COPY . .
问题是第三个
COPY有一个基于 multistage-build 功能的解决方案：
FROM node:12.18.2-alpine3.11
WORKDIR /app
COPY ["package.json", "yarn.lock", "./"]
# Step 2: Copy whole app
COPY packages packages
# Step 3: Find and remove non-package.json files
RUN find packages \! -name "package.json" -mindepth 2 -maxdepth 2 -print | xargs rm -rf
# Step 4: Define second build stage
FROM node:12.18.2-alpine3.11
WORKDIR /app
# Step 5: Copy files from the first build stage.
COPY --from=0 /app .
RUN yarn install --frozen-lockfile
COPY . .
# To restore workspaces symlinks
RUN yarn install --frozen-lockfile
CMD yarn start
在
Step 5packagesCOPY <src> <dest>COPY 指令从
复制新文件或目录，并将它们添加到路径<src>处的容器文件系统中。<dest>
针对您的情况
每个可能包含通配符，并且将使用 Go 的
规则进行匹配。filepath.Match
这些是规则。它们包含这个：
'*' 匹配任何非分隔符字符序列
因此，请尝试在您的模式中使用
***如果您无法在技术上枚举 Dockerfile 中的所有子目录（即为每个子目录编写
COPY packages/one/package.json packages/one/package.json.deps/docker build …yarn install --pure-lockfile将所有内容放在一起，可能会生成以下文件：
./build.bash:
#!/bin/bash
tag="image-name:latest"
rm -f -r .deps # optional, to be sure that there is
# no extraneous "package.json" from a previous build
find . -type d \( -path \*/.deps \) -prune -o \
-type f \( -name "package.json" \) \
-exec bash -c 'dest=".deps/$1" && \
mkdir -p -- "$(dirname "$dest")" && \
cp -av -- "$1" "$dest"' bash '{}' \;
# instead of mkdir + cp, you may also want to use
# rsync if it is available in your environment...
sudo docker build -t "$tag" .
和
./Dockerfile:
FROM …
WORKDIR /usr/src/app
# COPY package.json . # subsumed by the following command
COPY .deps .
# and not "COPY .deps .deps", to avoid doing an extra "mv"
COPY yarn.lock .
RUN yarn install --pure-lockfile
COPY . .
# Notice that "COPY . ." will also copy the ".deps" folder; this is
# maybe a minor issue, but it could be avoided by passing more explicit
# paths than just "." (or by adapting the Dockerfile and the script and
# putting them in the parent folder of the Yarn application itself...)
使用 Docker 的新 BuildKit 执行器，可以使用绑定挂载到 Docker 上下文中，然后您可以根据需要从中复制任何文件。
例如，以下代码片段将 Docker 上下文中的所有 package.json 文件复制到映像的
/app/不幸的是，更改挂载中的任何文件仍然会导致层缓存未命中。这可以使用@mbelsky提出的多阶段方法来解决，但这次不再需要显式删除。
# syntax = docker/dockerfile:1.2
FROM ... AS packages
WORKDIR /app/
RUN --mount=type=bind,target=/docker-context \
cd /docker-context/; \
find . -name "package.json" -mindepth 0 -maxdepth 4 -exec cp --parents "{}" /app/ \;
FROM ...
WORKDIR /app/
COPY --from=packages /app/ .
指定 mindepth
/
maxdepth参数是为了减少要搜索的目录数量，可以根据您的用例进行调整/删除。可能需要使用环境变量
DOCKER_BUILDKIT=1
启用BuildKit执行器，因为传统的执行器会默默地忽略绑定安装。有关 BuildKit 和绑定边界的更多信息
可以在此处找到。
dockerfile
，它利用BuildKit的力量来实现以下目标：
npm install通过将npm的缓存目录移动到构建缓存
npm install文件中没有任何更改，则跳过
package.json
package.json文件
package.json文件进行比较
npm install并缓存
package.json文件 +
node_modules文件夹
node_modules（新鲜或缓存）复制到图像中的所需位置
# syntax = docker/dockerfile:1.2
FROM node:14-alpine AS builder
# https://github.com/opencollective/opencollective/issues/1443
RUN apk add --no-cache ncurses
# must run as root
RUN npm config set unsafe-perm true
WORKDIR /app
# get a temporary copy of the package.json files from the build context
RUN --mount=id=website-packages,type=bind,target=/tmp/builder \
cd /tmp/builder/ && \
mkdir /tmp/packages && \
chown 1000:1000 /tmp/packages && \
find ./ -name "package.json" -mindepth 0 -maxdepth 6 -exec cp --parents "{}" /tmp/packages/ \;
# check if package.json files were changed since the last successful build
RUN --mount=id=website-build-cache,type=cache,target=/tmp/builder,uid=1000 \
mkdir -p /tmp/builder/packages && \
cd /tmp/builder/packages && \
(diff -qr ./ /tmp/packages/ || (touch /tmp/builder/.rebuild && echo "Found an updated package.json"));
USER node
COPY --chown=node:node . /app
# run `npm install` if package.json files were changed, or use the cached node_modules/
RUN --mount=id=website-build-cache,type=cache,target=/tmp/builder,uid=1000 \
echo "Creating NPM cache folders" && \
mkdir -p /tmp/builder/.npm && \
mkdir -p /tmp/builder/modules && \
echo "Copying latest package.json files to NPM cache folders" && \
/bin/cp -rf /tmp/packages/* /tmp/builder/modules && \
cd /tmp/builder/modules && \
echo "Using NPM cache folders" && \
npm config set cache /tmp/builder/.npm && \
if test -f /tmp/builder/.rebuild; then (echo "Installing NPM packages" && npm install --no-fund --no-audit --no-optional --loglevel verbose); fi && \
echo "copy cached NPM packages" && \
/bin/cp -rfT /tmp/builder/modules/node_modules /app/node_modules && \
rm -rf /tmp/builder/packages && \
mkdir -p /tmp/builder/packages && \
cd /app && \
echo "Caching package.json files" && \
find ./ -name "package.json" -mindepth 0 -maxdepth 6 -exec cp --parents "{}" /tmp/builder/packages/ \; && \
(rm /tmp/builder/.rebuild 2> /dev/null || true);
注意：
我只使用根文件夹的node_modules
，在我的例子中，内部文件夹中的所有包都被提升到根
您可以将
--parents
标志与
COPY指令一起使用。从Dockerfile 1.7.0-labs 开始可用：
# syntax=docker/dockerfile:1.7-labs
# syntax=
指令。
# syntax=docker/dockerfile:1.7-labs
FROM node:20-alpine AS build
WORKDIR /app
COPY --parents packages/*/package.json .
❯❯❯ docker build --tag foobarimg .
❯❯❯ docker run -it foobarimg sh
/app # find .
.
./packages
./packages/foo
./packages/foo/package.json
./packages/bar
./packages/bar/package.json