interactive

#!/bin/bash

set -e

default_time="08:00:00"

# Exceptions to defaults
if [ "$HOSTNAME" = "uhtred.inf.ed.ac.uk" ]; then
  # mlp cluter has a max time of 2hrs
  default_time="02:00:00"
fi

default_args="--time=${default_time} --mem=14000 --cpus-per-task=4"

print_welcome () {
  cat << EOM

=============================== WELCOME MESSAGE ===============================
It's good practice to set a few parameters when using srun (this command is
essentailly an alias for 'srun --pty bash'). We have added some default
parameters to maximise your chance of getting an interactive session. See the
Slurm Documentation for further info about parameters for srun:
    https://slurm.schedmd.com/srun.html

Default args added:
[$default_args]

Useful arg examples:
* --time=08:00:00        terminate job after 8 hours (good
                         practice and curteous)
* --time=1-04:00:30      terminate job after 1 day, 4 hours,
                         and 30 seconds
* --gres=gpu:1           give me 1 gpu
* --nodelist=charles19   put me on a specific node
* --mem=4000             give me 4G of RAM (note this is not GPU memory)
* --cpus-per-task=1      give me 1 cpu
* --partition=...        there is a likely a partition explicitly for
                         interactive jobs (called *-Interactive).
                         You are welcome to run interactive
                         jobs on other partitions if the
                         Interactive partition is full. To
                         get the full list of partitions, run "sinfo"

For more informtion about node configuration, see the computing support docs:
    http://computing.help.inf.ed.ac.uk/cluster-computing

===============================================================================
EOM
}

print_usage () {
  cat << EOM

A shortcut to get you an interactive session. Will attempt to get a session on
a node which is in a partition with 'interactive' in its name. You can hit
ctrl-c at any time, and it will try another partition if there is one
available to try.

Usage: $0 [-h] [other args for srun] 

Arguments:
    -h
        Print a friendly starter for 10
    [other args for srun]
        see documentation for srun:
            https://slurm.schedmd.com/srun.html
        You can specify arguments to this command exactly as you would for
        srun. If you specify any arguments, no defaults arguments will be used.

EOM
}


while getopts 'h' flag; do
  case "${flag}" in
    h) print_usage
       print_welcome
       exit 1 ;;
  esac
done


get_interactive_session() {
  srun_args=$@
  echo
  echo "Doing a --test-only to estimate wait time..."
  srun ${srun_args} --test-only --pty bash
  echo
  echo "Running the following command to get you an interactive session:"
  echo "srun ${srun_args} --pty bash"
  echo "..."
  srun ${srun_args} --pty bash
}


if [ $# -eq 0 ]; then
  args=$default_args
else
  # If the user supplies args, don't set any default args 
  args=$@
  get_interactive_session ${args}
  exit 0  # <-------------- EXIT 1 (user specifies args)
fi

interactive_partitions=`sinfo -o %R -h | grep -i interactive`
if [ -z "$interactive_partitions" ]; then
  echo "No partitions found with 'interactive' in their name"
  echo "Attempting to get a session on the default partition"
  get_interactive_session ${args}
  exit 0  # <-------------- EXIT 2 (no args, no interactive partitions)
else
  succeeded=0
  for partition in $interactive_partitions; do
    get_interactive_session --partition=${partition} ${args} \
      && succeeded=1 \
      || true
    if [ $succeeded -eq 1 ]; then
      exit 0  # <-------------- EXIT 3 (no args, interactive partition found)
    fi
  done
  # will only get here if all else fails:
  #   tried interactive partitions, trying the default partition
  get_interactive_session ${args}
  exit 0  # <-------------- EXIT 4 (no args, int part found but default used)
fi