Munin contributed plugins

#!/bin/bash

: << =cut

=head1 NAME

  zpool_capacity - Munin plugin to monitor ZFS capacity

  These functions are implemented:

    capacity  : to monitor zpool capacity %

    allocated : to monitor zpool allocated bytes

    dedup     : to monitor zpool dedup and compress ratio

  Tested with Solaris 10 and 11, OpenIndiana Hipster, FreeBSD 11, CentOS 7

=head1 CONFIGURATION

  Make symlink:

    cd /path/to/munin/etc/plugins

    ln -s /path/to/munin/lib/plugins/zpool_capacity .

  For FreeBSD, it should be necessary to change shebang /bin/bash -> /usr/local/bin/bash

  For Linux, root privilege is necessary to run zpool command.

    [zpool_capacity]

      user  root

=head1 ENVIRONMENT VARIABLES

  critical : default 90

  warning  : default 80

=head1 AUTHOR

  K.Cima https://github.com/shakemid

=head1 LICENSE

  GPLv2

=head1 Magic markers

  #%# family=contrib

  #%# capabilities=autoconf

=cut

# Include plugin.sh

. "${MUNIN_LIBDIR:-}/plugins/plugin.sh"

is_multigraph "$@"

# Shell options

set -o nounset

# Global variables

plugin_name=zpool_capacity

functions='capacity allocated dedup'

zpool_cmd=/sbin/zpool

zfs_cmd=/sbin/zfs

# Environment variables

: "${warning:=80}"

: "${critical:=90}"

# Note: The performance of ZFS may significantly degrade when zpool capacity > 90%

# See also: https://docs.oracle.com/cd/E53394_01/html/E54801/zfspools-4.html

# Functions

preconfig() {

    local func="$1"

    local p c

    # data_attr format: field type draw label

    #   label can contain white-spaces.

    data_attr=

    case $func in

    capacity)

        global_attr="

            graph_title ZFS storage pool - Capacity

            graph_category fs

            graph_args --base 1000 --lower-limit 0 --upper-limit 100

            graph_vlabel % allocated

            graph_info ZFS storage pool - Capacity

            warning ${warning}

            critical ${critical}

        "

        for p in $pool_list

        do

            data_attr="${data_attr}

                ${p} GAUGE LINE2 ${p}"

        done

        ;;

    allocated)

        global_attr="

            graph_title ZFS storage pool - Allocated bytes

            graph_category fs

            graph_args --base 1024 --lower-limit 0

            graph_vlabel Bytes

            graph_info ZFS storage pool - Allocated bytes

        "

        c=0

        for p in $pool_list

        do

            data_attr="${data_attr}

                ${p}_size      GAUGE LINE  ${p} size

                ${p}_allocated GAUGE LINE2 ${p} allocated"

            global_attr="${global_attr}

                ${p}_size.colour      COLOUR${c}

                ${p}_allocated.colour COLOUR${c}"

            c=$(( c + 1 ))

        done

        ;;

    dedup)

        global_attr="

            graph_title ZFS storage pool - Dedup and compress ratio

            graph_category fs

            graph_args --base 1000 --lower-limit 1

            graph_vlabel Ratio

            graph_info ZFS storage pool - Dedup and compress ratio

        "

        for p in $pool_list

        do

            data_attr="${data_attr}

                ${p}_dedup    GAUGE LINE ${p} dedup

                ${p}_compress GAUGE LINE ${p} compress"

        done

        ;;

    esac

}

do_config() {

    local func="$1"

    local label_max_length=45

    local field type draw label

    preconfig "$func"

    echo "multigraph ${plugin_name}_${func}"

    # print global attributes

    echo "$global_attr" | sed -e 's/^  *//' -e '/^$/d'

    # print data source attributes

    echo "$data_attr" | while read -r field type draw label

    do

        [ -z "$field" ] && continue

        field=$( clean_fieldname "$field" )

        echo "${field}.type ${type}"

        echo "${field}.draw ${draw}"

        echo "${field}.label ${label:0:${label_max_length}}"

        if [ "$type" = 'DERIVE' ]; then

            echo "${field}.min 0"

        fi

        if [ "$label" = 'dummy' ]; then

            echo "${field}.graph no"

        fi

    done

    echo

}

get_stats() {

    local func="$1"

    case $func in

    capacity)

        "$zpool_cmd" list -H -o name,capacity | sed 's/%$//'

        ;;

    allocated)

        ( "$zpool_cmd" list -H -o name,allocated \

          | awk '{ print $1"_allocated", $2 }'

          "$zpool_cmd" list -H -o name,size \

          | awk '{ print $1"_size", $2 }'

        ) \

        | perl -ane '

            @unit{ qw/ K M G T P E / } = ( 1 .. 6 );

            $name = $F[0];

            $byteu = $F[1];

            ( $n, $u ) = $byteu =~ /^([\d.]+)([KMGTPE]?)$/;

            $byte  = int( $n * 1024 ** ( $u ? $unit{ $u } : 0 ) );

            print "$name $byte\n";

        '

        # Note: ZFS supports up to 16EB.

        ;;

    dedup)

        "$zpool_cmd" list -H -o name,dedup \

        | sed 's/x$//' \

        | awk '{ print $1"_dedup", $2 }'

        # example output:

        #   $ zpool list -H -o name,dedup

        #   rpool   1.00x

        #   ...

        "$zpool_cmd" list -H -o name \

        | xargs "$zfs_cmd" get -H -o name,value compressratio \

        | sed 's/x$//' \

        | awk '{ print $1"_compress", $2 }'

        # example output:

        #   $ zfs get -H -o name,value compressratio rpool

        #   rpool   1.00x

        ;;

    esac

}

do_fetch() {

    local func="$1"

    local zpool_stats field value

    # zpool_stats contains 'key value\n'

    zpool_stats=$( get_stats "$func" )

    echo "multigraph ${plugin_name}_${func}"

    echo "$zpool_stats" | while read -r field value

    do

        field=$( clean_fieldname "$field" )

        echo "${field}.value ${value}"

    done

    echo

}

autoconf() {

    if [ -x "$zpool_cmd" ]; then

        echo yes

    else

        echo "no (failed to find executable 'zpool')"

    fi

}

config() {

    local func

    pool_list=$( "$zpool_cmd" list -H -o name )

    for func in $functions

    do

        do_config "$func"

    done

}

fetch() {

    local func

    for func in $functions

    do

        do_fetch "$func"

    done

}

# Main

case ${1:-} in

autoconf)

    autoconf

    ;;

config)

    config

    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi

    ;;

*)

    fetch

    ;;

esac

exit 0