#!/bin/bash

: <<'=cut'

=head1 NAME

vserver_resources - Plugin to graph  Vserver resource usage and limits

=head1 CONFIGURATION

This plugin uses the following configuration variables

 [vserver_resources]
  env.vservers - specify the vservers to include in the graph
  env.resource - specify the resource to be monitored
  env.limits   - if true, turn on limit graphing

=head2 DEFAULT CONFIGURATION

This is the default configuration

 [vserver_resources]
  env.vservers <all vservers>
  env.limits false

=head1 EXAMPLE CONFIGURATIONS

The following monitors the RSS value for the vservers named "vserver1
vserver2 vserver3 vserver4" and looks to see if the resource limit has
been breached, if so it sends a message to nagios via send_nsca, and
sends an email to notify that this has happened:

 [vserver_resources]
  user root
  env.vservers vserver1 vserver2 vserver3 vserver4
  env.resource RSS
  env.limits 1
  contacts nagios email
  contact.nagios.command /usr/bin/send_nsca -H your.nagios-host.here -c /etc/send_nsca.cfg
  contact.email.command mail -s "Munin-notification for ${var:group} :: ${var:host}" your@email.address.here

This second example monitors the VM value for all vservers on the system and
has no limit notifications turned on:

 [vserver_resources]
  user root
  env.vservers vserver5 vserver6 vserver7
  env.resource VM
  env.limits 0

This last example monitors all the resources for vserver5. Note that
this will be a busy graph, and it would be really useless if you
specified more than one vserver when the resource is set to ALL:

 [vserver_resources]
  user root
  env.vservers vserver5
  env.resource ALL
  env.limits 0

=head1 USAGE

Possible values for env.resource are:

=over 4

=item ALL

all the below resources

=item PROC

number of processes

=item VM

sum of all virtual pages inside the guest

=item VML

sum of all virtual pages locked into memory

=item RSS

number of pages currently present in RAM

=item ANON

number of anonymous memory pages

=item FILES

number of open files

=item OFD

=item LOCKS

=item SOCK

=item MSGQ

=item SHM

number of shared memory pages

=back

=head1 AUTHOR

  Copyright (C) 2006-2008 Holger Levsen
  Copyright (C) 2006-2008 Micah Anderson

=head1 LICENSE

GNU GPLv2

=begin comment

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 dated June, 1991.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

=end comment

=head1 TODO

=over 4

=item Less shell subprocesses

The plugin uses lots and lots of shell subprocesses.  Maybe factor
common vserver plugin code into Munin::Plugin::Linux::Vserver?

=item Multigraph

make it so you can specify more than one resource to be graphed?
Alternatively define combined resource-display: VM+RSS+ANON+SHM and
FILES+OFD+LOCK+SOCK (for one vserver only), and/or make it so you can
graph all resources for one vserver

=item Default resource

set a default for the resource if it is unset?

=item Use /proc less often

use /proc less often (100 times more overhead than talking to the
kernel directly) i.e. use something like pagesize=\`perl -MPOSIX -e
'print POSIX::sysconf(_SC_PAGESIZE), "\n";'\`

=back

=head1 BUGS

The "ALL" resource is broken

=head1 MAGIC MARKERS

  #%# family=auto
  #%# capabilities=autoconf

=cut

if [ "$1" = "autoconf" ]; then
	if [ -r /proc/virtual/info ]; then
		echo yes
	else
		echo "no (/proc/virtual/info not found)"
	fi
	exit 0
fi

VSERVERS="${vservers:-}"
LIMITS="${limits:-}"
RESOURCE="${resource:-}"

# shellcheck disable=SC2207
INFO=($(sed 's/.*:\t//' /proc/virtual/info 2>/dev/null || echo '<none>'))
KCIN=$(( 16#${INFO[2]} ))

# If this is 1, then VCI_SPACES is present in the kernel (new in 2.6.19)
if [ $(( (KCIN >> 10) & 1 )) -eq 1 ]
then
    NAMELOC="nsproxy"
else
    NAMELOC="cvirt"
fi

if [ -z "$VSERVERS" ] ; then
    XIDS=$(find /proc/virtual/* -type d -exec basename {} \;)
else
    # it's really more performant to specify vservers by ids or not at all
    XIDS=""
    for i in $VSERVERS ; do
        if [ -d "/proc/virtual/$i" ] ; then
            XIDS="${XIDS}${i} "
        else
            # shellcheck disable=SC2044
            for j in $(find /proc/virtual/* -type d -exec basename {} \;) ; do
                if [ "$i" = "$(grep "NodeName" "/proc/virtual/$j/$NAMELOC" | cut -f 2)" ]; then
                    XIDS="${XIDS}${j} "
                fi
            done
        fi
    done
fi

if [ "$1" = "config" ]; then
    case "$RESOURCE" in
	PROC)
	    echo 'graph_title Processes used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Processes'
	    echo 'graph_info Shows the number of processes used by each vserver.'
	    ;;
	VM)
	    echo 'graph_title Virtual memory used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel VM pages'
	    echo 'graph_info Shows virtual memory (human readable) used by each vserver.'
	    ;;
	VML)
	    echo 'graph_title Locked memory used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel VML pages'
	    echo 'graph_info Shows locked memory (human readable) used by each vserver.'
	    ;;
	RSS)
	    echo 'graph_title Resident set size used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel RSS pages'
	    echo 'graph_info Shows resident set size (human readable) used by each vserver.'
	    ;;
	ANON)
	    echo 'graph_title Anonymous memory used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel ANON pages'
	    echo 'graph_info Shows anonymous memory (human readable) used by each vserver.'
	    ;;
	FILES)
	    echo 'graph_title Files used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Files'
	    echo 'graph_info Shows files used by each vserver.'
	    ;;
	OFD)
	    echo 'graph_title Open filedescriptors used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Open filedescriptors'
	    echo 'graph_info Shows open filedescriptors used by each vserver.'
	    ;;
	LOCKS)
	    echo 'graph_title Locks used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Locks'
	    echo 'graph_info Shows locks used by each vserver.'
	    ;;
	SOCK)
	    echo 'graph_title Sockets used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Sockets'
	    echo 'graph_info Shows sockets used by each vserver.'
	    ;;
	MSGQ)
	    echo 'graph_title Message queues used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel Message queues'
	    echo 'graph_info Shows message queues used by each vserver.'
	    ;;
	SHM)
	    echo 'graph_title Shared memory used by vserver'
	    echo 'graph_args --base 1024k -l 0'
	    echo 'graph_vlabel SHM pages'
	    echo 'graph_info Shows shared memory (human readable) used by each vserver.'
	    ;;
	*)
	    echo "$RESOURCE not defined."
	    exit 1
	    ;;
    esac
    echo 'graph_category virtualization'


    # do not assume we are on i386 where pagesize is 4096...
    pagesize=$(perl -MPOSIX -e 'print POSIX::sysconf(_SC_PAGESIZE), "\n";')

    for xid in $XIDS ; do

	LABEL=$(grep "NodeName" "/proc/virtual/$xid/$NAMELOC" | cut -f 2)
	NAME=$(echo "$LABEL" | cut -d. -f1 |  tr '-' '_')

	case "$RESOURCE" in
	    PROC)
		echo "$NAME.label $LABEL: processes"
		echo "$NAME.info Number of processes used by $LABEL."
		;;
	    VM)
		echo "$NAME.label $LABEL: Virtual memory"
		echo "$NAME.info Size of virtual memory used by $LABEL. (Number multiplied by $pagesize to make it human readable)"
		echo "$NAME.cdef $NAME,$pagesize,*"
		;;
	    VML)
		echo "$NAME.label $LABEL: Locked memory"
		echo "$NAME.info Size of locked memory used by $LABEL. (Number multiplied by $pagesize to make it human readable)"
		echo "$NAME.cdef $NAME,$pagesize,*"
		;;
	    RSS)
		echo "$NAME.label $LABEL: Resident set size"
		echo "$NAME.info Size of resident set size used by $LABEL. (Number multiplied by $pagesize to make it human readable)"
		echo "$NAME.cdef $NAME,$pagesize,*"
		;;
	    ANON)
		echo "$NAME.label $LABEL: Anonymous memory"
		echo "$NAME.info Size of anonymous memory used by $LABEL. (Number multiplied by $pagesize to make it human readable)"
		echo "$NAME.cdef $NAME,$pagesize,*"
		;;
	    FILES)
		echo "$NAME.label $LABEL: Files"
		echo "$NAME.info Number of files used by $LABEL."
		;;
	    OFD)
		echo "$NAME.label $LABEL: Open filedescriptors"
		echo "$NAME.info Number of open filedescriptors used by $LABEL."
		;;
	    LOCKS)
		echo "$NAME.label $LABEL: Locks"
		echo "$NAME.info Number of locks used by $LABEL."
		;;
	    SOCK)
		echo "$NAME.label $LABEL: Sockets"
		echo "$NAME.info Number of sockets used by $LABEL."
		;;
	    MSGQ)
		echo "$NAME.label $LABEL: Message queues"
		echo "$NAME.info Number of message queues used by $LABEL."
		;;
	    SHM)
		echo "$NAME.label $LABEL: Shared memory"
		echo "$NAME.info Size of shared memory used by $LABEL. (Number multiplied by $pagesize to make it human readable)"
		echo "$NAME.cdef $1,$pagesize,*"
		;;
	    *)
		echo "$RESOURCE not defined."
		exit 1
		;;
	esac

	if [ -n "$LIMITS" ] && [ "$LIMITS" = 1 ]; then
	    LIMIT=$(grep "$RESOURCE" "/proc/virtual/$xid/limit" | cut -f 4)
	    if [ "${LIMIT:-0}" -gt 0 ]; then
		echo "$NAME.critical $LIMIT"
	    fi
	fi
    done
    exit 0
fi


for xid in $XIDS ; do
    LABEL=$(grep "NodeName" "/proc/virtual/$xid/$NAMELOC" | cut -f 2)
    NAME=$(echo "$LABEL" | cut -d. -f1 |  tr '-' '_')
    awk -v name="${NAME}" -v resource="${RESOURCE}:" \
        '{ if ( $1 == resource ) printf "%s.value %d\n", name, $2 }' \
        "/proc/virtual/$xid/limit"
done

