How to setup multiple ssh identities for single hg repository?

Question

I am using ssh publickey authentication for my mercurial repository. So I have:

[ui]
ssh = ssh -i ~/.ssh/id_rsa -C 

in my .hgrc. This works fine and allows me to push/pull to an ssh-authenticated repo. However, I want to be able to push/pull to another repo that requires a different identity. How can I configure my .hgrc file so the identity is tied to a particular path. I guess I'd want something like:

[ui]
one.prefix = someserver.com
one.ssh = ssh -i ~/.ssh/id_rsa -C
two.prefix = otherserver.com
two.ssh = ssh -i ~/.ssh/otherid_rsa -C

Answer 1

You do it using ssh's own tool: ssh-agent.

$ eval $(ssh-agent)
$ ssh-add ~/.ssh/id_rsa
$ ssh-add ~/.ssh/otherid_rsa

Then you don't need ssh identify related anything in your .hgrc's [ui] section at all.

Alternately you could do:

[ui]
ssh = ssh -i ~/.ssh/id_rsa -i ~/.ssh/otherid_rsa -C

but ssh-agent is useful in so many way's it's worth putting it your login scripts and calling it a day.

Answer 2

In your ~/.ssh/config, add

Host someserver.com
IdentityFile ~/.ssh/id_rsa

Host otherserver.com
IdentityFile ~/.ssh/otherid_rsa

and anybody (including hg and interactive use) using ssh to connect to hosts someserver.com or otherserver.com will use the specified identity files.

See ssh_config for other options.