npm install：有没有办法忽略package.json中的特定依赖项

Question

I am currently trying to create a docker container for a node.js project that contains a local dependency. This seems to cause an issue with docker so as a workaround I am trying to just copy the local dependency folders and just ignore their dependency entries in the package.json file. Is there a way to specify dependencies I would like to ignore and have npm install run and skip those enties?

Answer 1

That can be done using devDependencies

The npm modules which you require only to develop, eg: unit tests, Coffeescript to Javascript transpilation, minification etc,make the required module a devDependency.

To skip Installation of devDepenencies pass --production flag to npm install ,with the --production flag(or NODE_ENV environment variable set to production ) npm will not install modules listed in devDependencies."

npm install --production

To make any module to be part of devDependencies pass --dev while installing.

npm install packagename --save-dev

Answer 2

It is a common issue, not only with Docker, but also with some cloud deployments. For example deployment to CloudFoundry using standard Node.js buildpack will cause npm install / yarn to run anyway. So, you'll also need to apply some tricks to work with local modules

If you don't mind to switch from NPM to Yarn for dependency management, you can use workspaces feature.

My package.json looks like this:

{

  ...

  "dependencies": {
    "some-module-i-want-to-install": "1.0.0",
    "another-module-i-want-to-install": "1.0.0",
    "@my/local-dependency-one": "1.0.0",
    "@my/local-dependency-two": "1.0.0"
  },
  "workspaces": ["packages/*"]
}

And my project source layout has the following structure:

.
├── index.js
├── package.json
├── packages
│   ├── local-dependency-one
│   │   ├── index.js
│   │   └── package.json
│   └── local-dependency-two
│       ├── index.js
│       └── package.json
└── yarn.lock

After running yarn , modules I want to install are fetched from NPM registry, and local dependencies are installed from packages directory to node_modules .

.
├── index.js
├── node_modules
│   ├── @my
│   │   ├── local-dependency-one
│   │   │   └── ...
│   │   └── local-dependency-two
│   │       └── ...
│   ├── another-module-i-want-to-install
│   │   └── ...
│   └── some-module-i-want-to-install
│       └── ...
├── package.json
├── packages
│   ├── local-dependency-one
│   │   └── ...
│   └── local-dependency-two
│       └── ...
└── yarn.lock 

As you can see, I prefer to define my local packages as scoped ( @my/... ). It is not mandatory, but a best practice. NPM treats scoped packages as private by default , so I don't need to worry that they will be occasionally published or explicitly mark them as private.