Use npm install -g in ~/.local non-root

This articles presents the most convenient way to deal with global node packages as non-root user.

By default, npm install -g tries to write a root-writable directory and greets you with:

$ npm install -g cypress
WARN checkPermissions Missing write access to /usr/lib/node_modules
npm ERR! code EACCES
npm ERR! syscall access
npm ERR! path /usr/lib/node_modules
npm ERR! errno -13
npm ERR! Error: EACCES: permission denied, access '/usr/lib/node_modules'
npm ERR!  [Error: EACCES: permission denied, access '/usr/lib/node_modules'] {
npm ERR!   stack: "Error: EACCES: permission denied, access '/usr/lib/node_modules'",
npm ERR!   errno: -13,
npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'access',
npm ERR!   path: '/usr/lib/node_modules'
npm ERR! }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator.

You might even try with sudo, then it may work or:

$ sudo npm install -g cypress
/usr/bin/cypress -> /usr/lib/node_modules/cypress/bin/cypress

> cypress@3.8.3 postinstall /usr/lib/node_modules/cypress
> node index.js --exec install

Cypress cannot write to the cache directory due to file permissions

See discussion and possible solutions at
https://github.com/cypress-io/cypress/issues/1281

----------

Failed to access /root/.cache/Cypress:

EACCES: permission denied, mkdir '/root/.cache/Cypress'

----------

Platform: linux (Arch Linux - )
Cypress Version: 3.8.3
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! cypress@3.8.3 postinstall: `node index.js --exec install`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the cypress@3.8.3 postinstall script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2020-02-05T21_00_35_648Z-debug.log

It’s time to copy the practice Python users have with pip install --user which deploys in ~/.local

~/.local is a directory commonly used to store package files without polluting / which is not supposed to be writable by non-root users. It will contain directories such as /bin, /lib, /share, /etc, /include, /man …

The only trick is to bend npm with the $npm_config_prefix environment variable and change $PATH and $NODE_PATH as such:

export PATH=$HOME/.local/bin:$PATH
export NODE_PATH=$HOME/.local/lib/node_modules:$NODE_PATH
export npm_config_prefix=$HOME/.local

Then, both npm install -g and pip install --user will work as your normal user: you’re executing dependencies you’ve downloaded from internet, you’d like not to run them as root after all.

npm_config_prefix=$HOME/.local npm install -g cypress

If you have node but not npm, install it as such:

npm_config_prefix=$HOME/.local curl -L https://npmjs.org/install.sh | sh

Then, the cypress command will work, also tried the eslint package and it seems to work.

Have fun adding nodejs packages to your userland !