npm install -g に失敗した時の解決

npm install -gコマンドでエラーが出たため、その解決を行う

発生したエラー

$ npm install -g firebase-tools
npm WARN checkPermissions Missing write access to /usr/lib/node_modules
npm ERR! path /usr/lib/node_modules
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
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! 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 (though this is not recommended).

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/ec2-user/.npm/_logs/2019-03-02T21_35_10_898Z-debug.log

解決方法

使用するユーザーに設定用ディレクトリを作成する

$ mkdir ~/.npm-global
$ npm config set prefix '~/.npm-global'
$ echo ' export PATH=~/.npm-global/bin:$PATH' >> ~/.bash_profile
$ source ~/.bash_profile

結果

解決

$ npm install -g firebase-tools
/home/ec2-user/.npm-global/bin/firebase -> /home/ec2-user/.npm-global/lib/node_modules/firebase-tools/lib/bin/firebase.js

> @google-cloud/functions-emulator@1.0.0-beta.5 postinstall /home/ec2-user/.npm-global/lib/node_modules/firebase-tools/node_modules/@google-cloud/functions-emulator
> node scripts/upgrade-warning


If you're using the Emulator via the Firebase CLI, you can
disregard this message.

If you're upgrading @google-cloud/functions-emulator, these
are the recommended upgrade steps:

1.  Stop the currently running emulator, if any:

        functions stop

2.  Uninstall the current emulator, if any:

        npm uninstall -g @google-cloud/functions-emulator

3.  Install the new version of the emulator:

        npm install -g @google-cloud/functions-emulator

If you have trouble after upgrading, try deleting the config
directory found in:

    ~/.config/configstore/@google-cloud/functions-emulator

Then restart the emulator. You can also check for any renegade
Node.js emulator processes that may need to be killed:

    ps aux | grep node

+ firebase-tools@6.4.0
added 554 packages from 274 contributors in 11.874s