.npmrc

npm gets its configuration settings from the command line, environment variables and npmrc files.
There are four types of npmrc files
per project - /path/project/.npmrc
per user - ~/.npmrc
global config - $PREFIX/etc/npmrc
npm builtin config - /path/to/npmrc

All the files contain a list of key-value properties

npm config set registry https://----/group 
npm config set strict-ssl false