process.initgroups()

process.initgroups(user, extra_group)

Note: this function is only available on POSIX platforms (i.e. not Windows, Android)

Reads /etc/group and initializes the group access list, using all groups of which the user is a member. This is a privileged operation, meaning you need to be root or have the CAP_SETGID capability.

user is a user name or user ID. extra_group is a group name or group ID.

Some care needs to be taken when dropping privileges. Example:

console.log(process.getgroups());         // [ 0 ]
process.initgroups('bnoordhuis', 1000);   // switch user
console.log(process.getgroups());         // [ 27, 30, 46, 1000, 0 ]
process.setgid(1000);                     // drop root gid
console.log(process.getgroups());         // [ 27, 30, 46, 1000 ]