SSH key for Subversion but nothing else

I needed to create an account with an SSH key which could be used for Subversion, but nothing else.

The solution – forced commands with the SSH key – on the host machine, make ~/.ssh/authorized_keys look like:

command="/usr/bin/svnserve -t",from=""

Dumping this here mostly for my future reference, and for anyone who might find it useful.

This means the SSH private key on the client can be used by Subversion to check code in/out, but cannot be used for anything else (as SSH’ing to the host machine with that key simply starts ‘svnserve’, regardless of what the client asked for).