some LVM metrics for Prometheus

#!/bin/sh

while /bin/true; do
  echo "$(date) $0 run started"
  LVS_DATA=$(lvs --reportformat json)
  # lvm_lv_size_bytes
  echo '# HELP lvm_lv_size_bytes Size of logical volume in bytes.' > /monit/lvm_lv_size_bytes.prom
  echo '# TYPE lvm_lv_size_bytes gauge' >> /monit/lvm_lv_size_bytes.prom
  echo "$LVS_DATA"  \
    | jq -r --compact-output '.report[].lv[] | "lvm_lv_size_bytes{lv_name=\"\(.lv_name)\",vg_name=\"\(.vg_name)\",pool_lv=\"\(.pool_lv)\"}" + " " + (.lv_size | ascii_upcase)' \
    | numfmt --field 2 --from=auto \
    >> /monit/lvm_lv_size_bytes.prom
  # lvm_lv_data_percent
  echo '# HELP lvm_lv_data_percent Percent of logical volume used.' > /monit/lvm_lv_data_percent.prom
  echo '# TYPE lvm_lv_data_percent gauge' >> /monit/lvm_lv_data_percent.prom
  echo "$LVS_DATA"  \
    | jq -r --compact-output '.report[].lv[] | "lvm_lv_data_percent{lv_name=\"\(.lv_name)\",vg_name=\"\(.vg_name)\",pool_lv=\"\(.pool_lv)\"}" + " " + ((.data_percent | tonumber / 100) | tostring)' \
    >> /monit/lvm_lv_data_percent.prom
  sleep 60
done