2022-08-06

npm install で実行される npm-script を ignore-scripts オプションで無視する

はじめに

npm 管理化のアプリをコンテナ化する際、docker build でエラーとなったのでメモがてら原因と解決策をまとめる。以下の条件に当てはまる場合発生するっぽい。

npm prepare が npm-scripts（package.json 内の script 内）に設定してある
husky など上記の npm prepare で使用しているライブラリが devDependencies にあり Dockerfile では devDependencies をインストールしないようにしている
- npm install --omit=dev や npm ci --omit=dev になっている場合 devDependencies 内のライブラリはインストールされない

実際のエラーはこんな感じ。

$ docker build -t react-app .
[+] Building 53.2s (8/10)
 => [internal] load build definition from Dockerfile                                                                  0.3s
 => => transferring dockerfile: 37B                                                                                   0.2s
 => [internal] load .dockerignore                                                                                     0.4s
 => => transferring context: 112B                                                                                     0.3s
 => [internal] load metadata for docker.io/library/node:16.16.0-bullseye-slim                                         1.1s
 => [1/6] FROM docker.io/library/node:16.16.0-bullseye-slim@sha256:cda7229eb72b7534396e7b58ba5b9f2454aee188317e058cb  0.0s
 => [internal] load build context                                                                                     0.8s
 => => transferring context: 4.58MB                                                                                   0.7s
 => CACHED [2/6] WORKDIR /usr/local/app                                                                               0.0s
 => [3/6] COPY ./package*.json ./                                                                                     0.2s
 => ERROR [4/6] RUN npm install  --production                                                                         50.2s
------
 > [4/6] RUN npm install --omit=dev:
#8 48.98
#8 48.98 > [email protected] prepare
#8 48.98 > husky install
#8 48.98
#8 48.99 sh: 1: husky: not found
#8 48.99 npm notice
#8 48.99 npm notice New minor version of npm available! 8.11.0 -> 8.16.0
#8 48.99 npm notice Changelog: <https://github.com/npm/cli/releases/tag/v8.16.0>
#8 48.99 npm notice Run `npm install -g [email protected]` to update!
#8 48.99 npm notice
#8 48.99 npm ERR! code 127
#8 48.99 npm ERR! path /usr/local/app
#8 48.99 npm ERR! command failed
#8 48.99 npm ERR! command sh -c husky install
#8 48.99
#8 48.99 npm ERR! A complete log of this run can be found in:
#8 48.99 npm ERR!     /root/.npm/_logs/2022-08-04T14_28_44_690Z-debug-0.log
------
executor failed running [/bin/sh -c npm install --omit=dev]: exit code: 127

原因

npm prepare が package.json の npm-script に定義されている場合、npm install をトリガに npm prepare が実行されてしまう。

If the package being installed contains a prepare script, its dependencies and devDependencies will be installed, and the prepare script will be run, before the package is packaged and installed. — ref. npm-install | npm Docs

package.json の一部を抜粋すると…

package.json

{
  "name": "sample-app",
  "scripts": {
    "build": "next build",
    "prepare": "husky install" // npm install をトリガに実行される
    // ... 略 ...
  },
  "devDependencies": {
    "husky": "^7.0.0",
    // ... 略 ...
  }
}

また Dockerfile では devDependencies をインストールしないようにしていると husky がインストールされず husky: not found となる。

Dockerfile

...

RUN npm install --omit=dev

...

対策

本記事のタイトル通りだが ignore-scripts というオプションがあったので、それを使うと回避できる！

If true, npm does not run scripts specified in package.json files.

Note that commands explicitly intended to run a particular script, such as npm start, npm stop, npm restart, npm test, and npm run-script will still run their intended script if ignore-scripts is set, but they will not run any pre- or post-scripts. - ref. npm-install | npm Docs

Dockerfile

...

- RUN npm install --omit=dev
+ RUN npm install --omit=dev --ignore-scripts

...

上記のオプションを入れると無事に docker build が成功する。

$ docker build -t sample-app --no-cache .
[+] Building 383.4s (11/11) FINISHED
 => [internal] load build definition from Dockerfile                                                                  0.1s
 => => transferring dockerfile: 313B                                                                                  0.1s
 => [internal] load .dockerignore                                                                                     0.0s
 => => transferring context: 2B                                                                                       0.0s
 => [internal] load metadata for docker.io/library/node:16.16.0-bullseye-slim                                         1.2s
 => [1/6] FROM docker.io/library/node:16.16.0-bullseye-slim@sha256:cda7229eb72b7534396e7b58ba5b9f2454aee188317e058cb  0.0s
 => [internal] load build context                                                                                     8.3s
 => => transferring context: 3.24MB                                                                                   7.9s
 => CACHED [2/6] WORKDIR /usr/local/app                                                                               0.0s
 => [3/6] COPY ./package*.json ./                                                                                     1.0s
 => [4/6] RUN npm install --omit=dev --ignore-scripts                                                              96.0s
 => [5/6] COPY ./ ./                                                                                                 18.0s
 => [6/6] RUN npm run build                                                                                         225.7s
 => exporting to image                                                                                               32.4s
 => => exporting layers                                                                                              32.3s
 => => writing image sha256:fccc09cf65b8e3a429c177b9b0023be30b8537049366e723b537ebd3b0b291c8                          0.0s
 => => naming to docker.io/library/sample-app                                                                               0.0s

Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them