[HTCondor-devel] condor_ssh_to_job is cool, but DNS would be cooler

[Erik Paulson <epaulson@xxxxxxxxxxx>]

Jeff would kill me if I spent time implementing this, but what would be more awesome than condor_ssh_to_job would be for the schedd to speak DNS, so you could have things like:

<cluster>.<proc>.<scheddname>.condorjobs.cs.wisc.edu mapped to IP addresses. Ideally, you'd give the startd several IP addresses that it can map to slots, and as your job moves around the DNS mapping is updated (obviously, short DNS TTLs)

Have the startd also fire up an sshd for the job. Have a tool like condor_get_job_hostkey that gets the updated hostkey from the schedd when the job starts running somewhere. At job submit time, specify the public key(s) you'll want to be able to log in with. 

If the job is idle, map it back to the schedd*. Have the schedd (and maybe the startd) listen on a port speaking HTTP to cough up info about the job. Alternatively, just return host not found when the job is idle. 

The bummer about condor_ssh_to_job is that condor_ssh_to_job is your ssh client - and if you have a real ssh client you want to use, you're SOL. 

Having a job to DNS mapping gets you a good part of the way with Condor as a player in the IaaS world - you could run VM Universe jobs and be able to find them again.

-Erik

 

*it might be kind of fun to able to ssh to a schedd and interact with a simple shell.