#!/bin/bash

: << =cut

=head1 NAME

  fsstat_bytes - Munin plugin to monitor Solaris file system statistics

  Tested with Solaris 10 and 11.

  Note:
    In Solaris 11, fsstat command can get stats for each non-global zones in
    global zone. (see man fsstat)
    In global zone, this plugin gets stats of only global zone.
    In non-global zones, this plugin reports stats of the non-global zones.

=head1 CONFIGURATION

  Make symlink:
    cd /path/to/munin/etc/plugins
    ln -s /path/to/munin/lib/plugins/fsstat_bytes .

=head1 ENVIRONMENT VARIABLES

  env.exclude - file system(s) to exclude separated by white-space.
    example:  env.exclude  autofs
    default:  none

=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"

# Shell options
set -o nounset  # Like perl use strict;

# Set environment variables
name_regexp='/^vopstats_(?![0-9a-f]{7})[a-z]/'  # data source of fsstat
: "${exclude:=}"

# Set graph settings
global_attr="
    graph_title File system statistics - I/O throughput
    graph_category disk
    graph_args --base 1024
    graph_vlabel Bytes per second write (-) / read (+)
    graph_info File system statistics - I/O throughput
"
data_in=read_bytes
data_out=write_bytes


# Functions

is_excluded() {
    local arg i
    arg=$1

    for i in ${exclude}
    do
        if [ "$arg" = "$i" ]; then
            return 0
        fi
    done

    return 1
}

get_zone_id() {
    local osver zonename zoneid

    # Note: Solaris 11 fsstat supports statistics per zone. Solaris 10 does not.

    zoneid=0
    osver=$( uname -r | cut -d. -f2 )

    if [ "$osver" -ge 11 ]; then
        zonename=$( zonename )
        zoneid=$( /usr/sbin/zoneadm list -p | awk -F: '$2 == "'"$zonename"'" { print $1 }' )
    fi

    echo "$zoneid"
}

autoconf() {
    if which kstat >/dev/null ; then
        echo yes
    else
        echo "no (failed to find executable 'kstat')"
    fi
}

config() {
    local fs

    # Print global attributes
    echo "$global_attr" | sed -e 's/^  *//' -e '/^$/d'

    # Get fs names by kstat
    kstat -p "unix:${zone_id}:${name_regexp}:${data_in}" \
    | sed -e 's/vopstats_//' -e 's/:/ /g' | awk '{ print $3 }' | sort \
    | while read -r fs
    do
        is_excluded "$fs" && continue

        # Print data attributes
        echo "${fs}_${data_out}.label dummy"
        echo "${fs}_${data_out}.graph no"
        echo "${fs}_${data_out}.type DERIVE"
        echo "${fs}_${data_out}.min 0"

        echo "${fs}_${data_in}.label ${fs}"
        echo "${fs}_${data_in}.negative ${fs}_${data_out}"
        echo "${fs}_${data_in}.type DERIVE"
        echo "${fs}_${data_in}.min 0"
    done
}

fetch() {
    local fs stat value

    # Get fs names, stat names and values by kstat

    # kstat output example:
    #  $ kstat -p 'unix::/^vopstats_[a-z]/:nread'
    #  unix:0:vopstats_autofs:nread    2
    #  unix:0:vopstats_hsfs:nread      407790
    #  ...

    kstat -p "unix:${zone_id}:${name_regexp}:/^(${data_in}|${data_out})\$/" \
    | sed -e 's/vopstats_//' -e 's/:/ /g' | awk '{ print $3,$4,$5 }' \
    | while read -r fs stat value
    do
        is_excluded "$fs" && continue

        echo "${fs}_${stat}.value ${value}"
    done
}

# Main

zone_id=$( get_zone_id )

case ${1:-} in
autoconf)
    autoconf
    ;;
config)
    config
    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
    ;;
*)
    fetch
    ;;
esac

exit 0