how to use borg serve 2.0.0b23

[tve]

I'm probably not understanding and doing something really stupid, but... I'm trying to use borg serve --rest and it's not working on the client end. On the client I'm not managing to tell it to use http-over-ssh:

# /home/borg/bin/borg-v200b23 repo-info -r rest://dcm/
Repository proto='file', user=None, pass=None, host=None, port=None, path='/home/borg/rest:/dcm' does not exist.

I've tried numerous permutations of the rest: URL but it always thinks it's a local directory and prefixed the CWD.

[ThomasWaldmann]

Hmm, looks like the wrong (local file) regex is matching this.

Can you try with user@host?

[gitsult4n]

The URL has no path. rest_re wants at least one character after the separating slash:

rest://(user@host(:port))?/PATH      PATH = .+

rest://dcm/ leaves PATH empty, so it does not match, falls through to the local path branch, normpath folds it to rest:/dcm, and that gets resolved against your cwd. That is the /home/borg/rest:/dcm in your error. Running the 2.0.0b23 regexes on your input:

'rest://dcm/'               -> no match, local path 'rest:/dcm'
'rest://dcm/repo'           -> rest host=dcm path='repo'
'rest://dcm//srv/borg/repo' -> rest host=dcm path='/srv/borg/repo'

user@ will not help by itself, the path is what is missing:

'rest://borg@dcm/'     -> no match, local path 'rest:/borg@dcm'
'rest://borg@dcm/repo' -> rest user=borg host=dcm path='repo'

Same slash rule as ssh://. One slash is relative to the ssh login dir, two for an absolute path:

borg repo-info -r rest://dcm//srv/borg/repo

You do not start anything on the server. With a host in the URL the client runs ssh dcm borg serve --rest --backend FILE:<path> itself, repository.py:92 rest_serve_command and :125 build_rest_backend. If you do run it by hand it needs --backend FILE:<path>, archiver/serve_cmd.py:31 bails out without it.

[ThomasWaldmann]

Not stupid at all - you hit a bug. rest://dcm/ has no repository path, so it did not match the rest:// regex, fell through to the local-path regex and ended up being treated as the local directory ./rest:/dcm. That is where the path='/home/borg/rest:/dcm' in the error came from.

Two things to make it work:

1. The path is not optional. Use one of:

• rest://dcm/path/to/repo - path relative to the directory the ssh login lands in (usually the remote user's home)
• rest://dcm//path/to/repo - absolute path (note the two slashes)

2. You do not start borg serve --rest yourself. The client does it: it ssh'es to the host and runs borg serve --rest --backend FILE:<path> there, same idea as ssh:// in borg 1.x. So on the client just do:

borg -r rest://dcm/path/to/repo repo-info

Since you are running borg under a non-standard name/path (/home/borg/bin/borg-v200b23), the remote borg is probably not called plain borg either - in that case tell the client what to invoke on the server side:

BORG_REMOTE_PATH=/home/borg/bin/borg-v200b23 borg-v200b23 -r rest://dcm/path/to/repo repo-info

I have fixed the parsing in #10216: such a URL is now rejected right away instead of being silently taken for a local path, and the error tells you the accepted forms:

error: argument -r/--repo: Invalid location format: "rest://dcm/". Expected: rest://[user@]host[:port]/path/to/repo (path relative to the remote directory ssh logs into) or rest://[user@]host[:port]//path/to/repo (absolute path)

The docs were misleading here too (quickstart suggested rest://borg@remote_host without a path, which would have run into exactly this), that is fixed as well.

^ analysis, fix and response by Claude Opus 5.

[tve]

Thanks for all the info, I'll try it out.
I do want to ask, though: I had hoped I could put the borg serve --rest --backend PATH command into the .ssh/authorized_keys in order to restrict the client to only access the specified repo. I gather this is not possible?

[ThomasWaldmann]

There are other options for these restrictions, quite similar as in borg1. Do not give --backend in the forced command.

[ThomasWaldmann]

Fixed in master branch, #10216.