#!/usr/bin/env python3

from subprocess import check_output

pools = check_output(
    ['/usr/sbin/zpool', 'list', '-Hpo', 'name,free,size'],
    env={
        'LC_ALL': 'C',
    },
).decode('UTF-8')

datasets = check_output(
    ['/usr/sbin/zfs', 'list', '-Hpo', 'name,usedbydataset,usedsnap,compressratio'],
    env={
        'LC_ALL': 'C',
    },
).decode('UTF-8')

zpools = {}
for line in pools.splitlines():
    name, free, total = line.split()

    zpools[name] = {
        'free': free,
        'total': total,
    }

    print('zfs_pool,pool={} size={}i,free={}i'.format(name, total, free))

for line in datasets.splitlines():
    name, used, usedsnap, compressratio = line.split()

    pool = name.split('/')[0]

    if '/' not in name:
        # covered by pool metrics above
        continue

    if pool not in zpools:
        raise Exception('BUG: {} in datasets, but {} not in pools'.format(name, pool))

    if compressratio[-1] == 'x':
        compressratio = compressratio[:-1]

    print('zfs_dataset,pool={},dataset={} used={}i,usedsnap={}i,compressratio={}'.format(
        pool,
        name,
        used,
        usedsnap,
        compressratio,
    ))