userdata.sh.tftpl

#!/bin/bash
# Runs at boot on each fleet instance. vanity is prebaked in the AMI (no network
# needed). Found keypairs are printed to /dev/shm/grind.out (tmpfs only, never EBS).
# The poller reads grind.out LIVE and extracts keys, so this works even when vanity
# keeps running (multi-key / hard prefix) and never exits before teardown.
exec >/var/log/grind.log 2>&1
set -x

export PATH=/usr/local/bin:/usr/local/cuda/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/cuda/lib64:$${LD_LIBRARY_PATH}

echo "running" > /dev/shm/grind.status

GPUS=$(nvidia-smi -L | wc -l)
echo "detected $GPUS GPU(s)"

# vanity prints results (incl. the keypair json) to STDERR, so 2>&1 is REQUIRED.
# --count is baked into the args so a node does not idle after its first find.
vanity grind-keypair ${vanity_args} --num-gpus "$GPUS" 2>&1 | tee /dev/shm/grind.out

echo "done" > /dev/shm/grind.status