Configless Slurm support

[natefoo]

Slurm 20.02+ supports a Configless mode where a physical copy of slurm.conf is not required, clients and slurmds can locate the slurmctld using DNS SRV records.

Direct support in slurm-drmaa would be ideal, but as a workaround, you can use scontrol write config to write a local copy of slurm.conf and set $SLURM_CONF to the path of that file.

e.g. this script (not shown, $SLURM_CONF is set to ${HOME}/etc/slurm.conf in the configuration of the process manager that runs the application).