#!/bin/sh
# Managed by Ansible - DO NOT EDIT MANUALLY
#
# Writes ZFS pool and dataset capacity metrics as Prometheus textfile metrics
# into node_exporter's textfile collector directory. node_exporter's built-in
# --collector.zfs exposes ARC, pool I/O and pool state only, not capacity.
set -eu
set -o pipefail

metrics_dir="{{ zfs_metrics_dir }}"

# node_exporter may not be deployed on this host.
[ -d "$metrics_dir" ] || exit 0

out="$metrics_dir/zfs.prom"
tmp="$out.tmp"

# Written atomically (tmp + mv) so the collector never reads a half-written file.
{
    echo "# HELP zfs_pool_size_bytes Total size of the ZFS pool."
    echo "# TYPE zfs_pool_size_bytes gauge"
    echo "# HELP zfs_pool_alloc_bytes Allocated bytes in the ZFS pool."
    echo "# TYPE zfs_pool_alloc_bytes gauge"
    echo "# HELP zfs_pool_free_bytes Free bytes in the ZFS pool."
    echo "# TYPE zfs_pool_free_bytes gauge"
    echo "# HELP zfs_pool_capacity_percent Used capacity of the ZFS pool, in percent."
    echo "# TYPE zfs_pool_capacity_percent gauge"
    echo "# HELP zfs_dataset_used_bytes Used bytes of a ZFS dataset, including snapshots and children."
    echo "# TYPE zfs_dataset_used_bytes gauge"
    echo "# HELP zfs_dataset_refer_bytes Bytes referenced by a ZFS dataset itself."
    echo "# TYPE zfs_dataset_refer_bytes gauge"
    echo "# HELP zfs_dataset_quota_bytes Quota of a ZFS dataset in bytes (0 = no quota)."
    echo "# TYPE zfs_dataset_quota_bytes gauge"

    zpool list -Hp -o name,size,alloc,free,capacity | while read -r pool size alloc free capacity; do
        echo "zfs_pool_size_bytes{pool=\"$pool\"} $size"
        echo "zfs_pool_alloc_bytes{pool=\"$pool\"} $alloc"
        echo "zfs_pool_free_bytes{pool=\"$pool\"} $free"
        echo "zfs_pool_capacity_percent{pool=\"$pool\"} $capacity"
    done

    zfs list -Hp -o name,used,refer,quota -t filesystem | while read -r dataset used refer quota; do
        echo "zfs_dataset_used_bytes{dataset=\"$dataset\"} $used"
        echo "zfs_dataset_refer_bytes{dataset=\"$dataset\"} $refer"
        echo "zfs_dataset_quota_bytes{dataset=\"$dataset\"} $quota"
    done
} > "$tmp"

mv "$tmp" "$out"