"run.sh" fails to install pnpm when not running as root

[RalfJung]

Describe the bug
I am trying to update to etherpad 2.2.7 (current version is 1.9.7). Running run.sh fails with a permission error:

Jan 05 12:54:48 systemd[1]: Started etherpad-lite.service - etherpad-lite (real-time collaborative document editing).
Jan 05 12:54:49 run.sh[38599]: npm ERR! code EACCES
Jan 05 12:54:49 run.sh[38599]: npm ERR! syscall mkdir
Jan 05 12:54:49 run.sh[38599]: npm ERR! path /usr/local/lib/node_modules
Jan 05 12:54:49 run.sh[38599]: npm ERR! errno -13
Jan 05 12:54:49 run.sh[38599]: npm ERR! Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules'
Jan 05 12:54:49 run.sh[38599]: npm ERR!  [Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules'] {
Jan 05 12:54:49 run.sh[38599]: npm ERR!   errno: -13,
Jan 05 12:54:49 run.sh[38599]: npm ERR!   code: 'EACCES',
Jan 05 12:54:49 run.sh[38599]: npm ERR!   syscall: 'mkdir',
Jan 05 12:54:49 run.sh[38599]: npm ERR!   path: '/usr/local/lib/node_modules'
Jan 05 12:54:49 run.sh[38599]: npm ERR! }
Jan 05 12:54:49 run.sh[38599]: npm ERR!
Jan 05 12:54:49 run.sh[38599]: npm ERR! The operation was rejected by your operating system.
Jan 05 12:54:49 run.sh[38599]: npm ERR! It is likely you do not have the permissions to access this file as the current user

I suspect this is npm install pnpm -g failing. Apparently it tries to write to /usr. The run.sh script itself bails out when running as root, so it seems like the logic in installDeps.sh that installs pnpm doesn't seem to make a lot of sense?

To Reproduce
Steps to reproduce the behavior:

1. Run run.sh on a system without pnpm installed.

Expected behavior
Etherpad should start up successfully.

Server (please complete the following information):

• Etherpad version: 2.2.7
• OS: Debian 12
• Node.js version (node --version): v18.19.0
• npm version (npm --version): 9.2.0

Additional context
I will definitely not run npm as root, so I am currently unsure how I could install pnpm. Somehow it should be installed only for the user that runs etherpad.

[SamTV12345]

Hey. There is also some extra possibilities how to install pnpm https://pnpm.io/installation . You could use corepack for this.

[RalfJung]

Is there a way to use npm install without -g and just install something for the local user? Something like pip install --local or cargo install, neither of which need root permissions.

I am not a nodejs/npm user myself so it's quite hard to figure this out based on just the etherpad docs.