When the run-if boostrap action doesn't work...

gistfile1.txt

check_if_master() {
python - <<'__SCRIPT__'
import sys
import json

instance_file = "/mnt/var/lib/info/instance.json"
with open(instance_file) as f:
    props = json.load(f)

is_master = props.get('isMaster', False)
if is_master:
    sys.exit(0)
else:
    sys.exit(1)
__SCRIPT__
}