#!/bin/sh

: << =cut

=head1 NAME

ejabberd_ - Munin wildcard plugin to monitor ejabberd2

=head1 CONFIGURATION

As connected users, registered users and server-connections have
somewhat different scales, this plugin uses munins suggest feature to
create the following graphs:

ejabberd_connections

ejabberd_memory

ejabberd_registrations

ejabberd_statuses

ejabberd_threads

ejabberd_uptime

ejabberd_users


If the autodetect-feature for vhosts breaks, you can set

=over 4

  [ejabberd_*]
    env.vhosts foo.com bar.com

=back

in a file in plugin-conf.d to override it.  ("user root" may also be
smart/not so smart depending on your setup).

For monitoring user statuses - define statuses environment variable:
(you can monitor only some of them)

=over 4

  [ejabberd_*]
    env.statuses available away chat xa

=back

If your ejabberd.cfg cannot be found you can se it this way

=over 4

  [ejabberd_*]
    env.configfile /etc/ejabberd/ejabberd.cfg

=back

=head1 MAGIC MARKERS

  #%# family=contrib
  #%# capabilities=autoconf suggest

=head1 AUTHOR

Written by Lasse Karstensen <lkarsten@hyse.org>.  Based on
ejabberd-plugin by Christian Dröge <Christian@draugr.de>

Status, memory, threads, uptime, usersindays, ejabberd2 and other code
optimisation by Peter Viskup <skupko.sk@gmail.com>

=head1 LICENSE

Unknown

=head1 BUGS

Previously the documentation for this plugin mentioned RRDs limit on
data series names.  Munin works around this limit and the restriction
does not apply.

There is no way to configure the path to ejabberdctl.

=cut

set -eu


# configurable environment variables
# list of client statuses (space-separated) for the graph "statuses"
statuses=${statuses:-"available away chat xa"}
# statically configured list of vhosts provided by the ejabberd server
vhosts=${vhosts:-}
# location of ejabberd configuration file for parsing the configured vhosts
# (empty: search in default locations)
configfile=${configfile:-}


EJCTL=$(command -v ejabberdctl || true)
# get ejabberd PID
# in GNU/Linux Debian Lenny release the pidof command can be executed only by root
#EJPID=$(pidof -s /usr/lib/erlang/erts-5.6.3/bin/beam.smp)
EJPID=$(ps -ef | awk '/ejabberd/ && /\/bin\/beam(.smp)?/ {print $2}')
SUPPORTED_MODES="connections users registrations statuses memory threads uptime"

# shellcheck disable=SC1090
. "$MUNIN_LIBDIR/plugins/plugin.sh"


if [ "${1:-}" = "autoconf" ]; then
    if [ -n "$EJCTL" ] && [ -x "$EJCTL" ]; then
        echo yes
    else
        echo "no (ejabberdctl not found in path)"
    fi
    exit 0
fi

if [ "${1:-}" = "suggest" ]; then
    for mode in $SUPPORTED_MODES; do
        echo "$mode"
    done
    exit 0
fi


# Try to parse a yaml based configuration file for ejabberd. We just hope for a non-cluttered
# format - otherwise our stupid parser will fail. See below for acceptable format examples.
parse_vhosts_from_config_yaml() {
    local filename="$1"
    local vhosts
    # try to parse a single-line yaml list, e.g.:
    #   hosts: ["foo.example.org", 'bar.example.com']
    vhosts=$(grep -E '^hosts:\s*\[' "$filename" \
        | sed -E 's/^.*\[(.+)].*$/\1/' \
        | tr ',' '\n' \
        | sed -E 's/^.*["'\''](.+)["'\''].*$/\1/')
    if [ -z "$vhosts" ]; then
        # try to parse a multi-line yaml list, e.g.:
        #    hosts:
        #      - "foo.example.org"
        #      - 'bar.example.com'
        vhosts=$(grep -vE '^(\s*#|$)' "$filename" \
            | sed -n '/^hosts:$/,/^\w/p;' \
            | grep '^\s*-' \
            | sed -E 's/^.+["'\''](.*)["'\'']\s*$/\1/')
    fi
    echo "$vhosts"
}


# Try to parse the old ejabberd configuration format (*.cfg).
# Output one vhost per line.
parse_vhosts_from_config_cfg() {
    local filename="$1"
    awk '/^\s*{hosts/ {gsub( /\{\s?hosts\s?,|[\",\[\]]|\}\s?.|localhost/ ,""); print;}' "$filename"
}


# Search for the configuration file and parse its vhosts definition.
# Either a yaml file or a cfg file will be parsed automatically.
# The function will either fail (returning an errorcode) or output the vhosts (one per line).
parse_vhosts_from_config() {
    local cfg_dir
    local cfg_file
    local vhosts
    if [ -n "$configfile" ]; then
        # a specific filename was configured
        if [ ! -f "$configfile" ]; then
            echo "The filename defined in the 'configfile' setting does not exist: $configfile" >&2
            return 1
        fi
    else
        # search in default locations
        for cfg_dir in /etc/ejabberd /etc/ejabber /usr/local/ejabberd/etc; do
            for cfg_file in ejabberd.cfg ejabberd.yml; do
                if [ -f "$cfg_dir/$cfg_file" ]; then
                    configfile=$cfg_dir/$cfg_file
                    break
                fi
            done
            if [ -n "$configfile" ]; then
                break
            fi
        done
    fi
    if [ -z "$configfile" ]; then
        echo "Unable to find ejabberd config file. Maybe specify 'configfile' setting." >&2
        return 1
    else
        # we found a config (or its location was specified)
        if echo "$configfile" | grep -qi '\.cfg$'; then
            vhosts=$(parse_vhosts_from_config_cfg "$configfile")
        else
            vhosts=$(parse_vhosts_from_config_yaml "$configfile")
        fi
        if [ -z "$vhosts" ]; then
            echo "Failed to parse vhosts from configuration file: $configfile" >&2
            echo "Maybe you want to either simplify the format of the configuration (for our" \
                "stupid parser) or specify the 'vhosts' environment variable directly." >&2
            return 1
        else
            echo "$vhosts"
        fi
    fi
}


# the vhosts can be defined via environment or parsed
if [ -z "$vhosts" ]; then
    # exit in case of failure (error messages were emitted before)
    vhosts=$(parse_vhosts_from_config) || exit 1
fi

MODE=$(basename "$0" | sed 's/^ejabberd_//g')

if ! echo "$SUPPORTED_MODES" | grep -qwF "$MODE"; then
    echo "ERROR: Unknown mode '$MODE'. Exiting." >&2
    exit 1
fi

if [ "${1:-}" = "config" ]; then
    if [ "$MODE" = "memory" ]; then
        echo 'graph_args --base 1024 -l 0'
        echo 'graph_scale yes'
        echo 'graph_category chat'
        echo 'graph_info This graph shows a statistic of ejabberd'
        echo 'graph_title Memory of ejabberd process'
        echo 'graph_vlabel Bytes'
        echo "ejabberd_memory_size.label actual memory"
        echo "ejabberd_memory_size.info Memory used by ejabberd process in Bytes"
        echo "ejabberd_memory_peak.label memory peak"
        echo "ejabberd_memory_peak.info Memory peak of ejabberd process in Bytes"
    else
        echo 'graph_args --base 1000 -l 0'
        echo 'graph_scale no'
        echo 'graph_category ejabberd'
        echo 'graph_info This graph shows a statistic of ejabberd'

        if [ "$MODE" = "connections" ]; then
            echo 'graph_title Server-to-server connections'
            echo 'graph_vlabel s2s'
            echo 's2s_connections_out.label incoming s2s connections'
            echo 's2s_connections_out.info Number of outgoing server to server connections'
            echo 's2s_connections_in.label outgoing s2s connections'
            echo 's2s_connections_in.info Number of incoming server to server connections'
        elif [ "$MODE" = "users" ]; then
            echo 'graph_title Connected users'
            echo 'graph_vlabel users'
            for host in $vhosts; do
                formathost=$(clean_fieldname "$host")
                echo "connected_users_$formathost.label $host connected users"
                echo "connected_unique_users_$formathost.label $host unique connected users"
            done
        elif [ "$MODE" = "registrations" ]; then
            echo 'graph_title Number of registered users'
            echo 'graph_vlabel users'
            for host in $vhosts; do
                formathost=$(clean_fieldname "$host")
                echo "registered_$formathost.label $host registered users"
                echo "registered_$formathost.info Registered users for vhost $host"
            done
        elif [ "$MODE" = "statuses" ]; then
            echo 'graph_title Users with statuses'
            echo 'graph_vlabel users'
            for host in $vhosts; do
                for status in $statuses; do
                    formathost=$(clean_fieldname "$host")
                    echo "status_${formathost}_${status}.label $status on $host"
                    echo "status_${formathost}_${status}.info Number of users with status $status on $host [available, away, xa=not available, dnd=(do not disturb) or (busy), chat=free for chat]"
                done
            done
        elif [ "$MODE" = "threads" ]; then
            echo 'graph_title Threads of ejabberd process'
            echo 'graph_vlabel threads'
            echo "ejabberd_threads.label number of threads"
            echo "ejabberd_threads.info Number of threads of ejabberd process"
        elif [ "$MODE" = "uptime" ]; then
            echo 'graph_title Uptime of ejabberd server'
            echo 'graph_vlabel uptime in days'
            echo "uptime.label uptime"
            echo 'uptime.draw AREA'
        fi
    fi
    exit 0
fi

if [ "$MODE" = "connections" ]; then
    echo "s2s_connections_out.value $("$EJCTL" outgoing-s2s-number)"
    echo "s2s_connections_in.value $("$EJCTL" incoming-s2s-number)"
    exit 0
fi

if [ "$MODE" = "users" ]; then
    for host in $vhosts; do
        formathost=$(clean_fieldname "$host")
        echo "connected_users_$formathost.value $("$EJCTL" stats-host onlineusers "$host")"
        echo "connected_unique_users_$formathost.value $("$EJCTL" connected-users | awk -v "var=$host" -v count=0 -F/ '{users[$1]} END {for (user in users) {if (index(user,var)) {count++}} print count}')"
    done
    exit 0
fi

if [ "$MODE" = "registrations" ]; then
    for host in $vhosts; do
        formathost=$(clean_fieldname "$host")
        num=$("$EJCTL" stats-host registeredusers "$host") || num="U"
        echo "registered_$formathost.value $num"
    done
    exit 0
fi

if [ "$MODE" = "statuses" ]; then
   for host in $vhosts; do
        formathost=$(clean_fieldname "$host")
        for status in $statuses; do
            num=$("$EJCTL" status-num-host "$host" "$status") || num="U"
            echo "status_${formathost}_${status}.value $num"
        done
    done
    exit 0
fi

if [ "$MODE" = "memory" ]; then
    echo "ejabberd_memory_size.value $(awk '/VmSize/ {print $2*1024}' "/proc/${EJPID}/status")"
    echo "ejabberd_memory_peak.value $(awk '/VmPeak/ {print $2*1024}' "/proc/${EJPID}/status")"
    exit 0
fi

if [ "$MODE" = "threads" ]; then
    echo "ejabberd_threads.value $(awk '/Threads/ {print $2}' "/proc/${EJPID}/status")"
    exit 0
fi

if [ "$MODE" = "uptime" ]; then
    echo "uptime.value $("$EJCTL" stats uptimeseconds | awk '{printf "%.2f", $1/86400}')"
fi
