munin-host-rename

#!/usr/bin/env bash
# (c) 2011, Stefan Schlesinger, sts@ono.at
#
# munin-host-rename - Rename a host in munin.
#
#
# Usage:
#
# munin-host-rename <Hostgroup> <Old-Hostname> <New-Hostname>



# Configuration
RRD=/var/lib/munin
HTML=/var/www/munin
BACKUP=/var/tmp/munin




########## COMMAND LINE ARGUMENTS
GROUP=$1 ; HOST=$2 ; HOSTNEW=$3

if [ $# -ne  3 ]; then
    echo "Usage: $0 <Hostgroup> <Old-Hostname> <New-Hostname>"
    echo "munin-host-rename - Rename a munin host."
    echo "You need sudo privileges and should disable munin-cron."
    exit 100
fi

########## DIRECTORIES
RRDDIR="${RRD}/${GROUP}"
HTMLDIR="${HTML}/${GROUP}"
BACKDIR="${BACKUP}/${GROUP}/${HOST}"




########## FUNCTIONS
prompt_user() {
read safetypin
if [ "$safetypin" != "y" ]; then
        echo '>>>> ABORTING MUNIN HOST RENAME, AT YOUR DISCRETION!'
        exit 3
fi
}

check_rc() {
RC=$?
if [ $RC -ne 0 ]; then
        echo "Failed: $1"
        echo "RC was $RC. Bailing out"
        exit 4
fi
}



########## USER CONFIRMATION
echo
echo "MUNIN-HOST-RENAME --------------------------------------------------"
echo
echo " * RRD  Directory   : ${RRDDIR}"
echo " * HTML Directory   : ${HTMLDIR}"
echo " * BACKUP Directory : ${BACKDIR}"
echo 
echo " * Hostgroup    : ${GROUP}"
echo " * Old-Hostname : ${HOST}"
echo " * New-Hostname : ${HOSTNEW}"
echo
echo -n "Is that correct? (y/N) "
prompt_user


########## SANITY CHECKS

# Suppose other distributions or systems might use other paths,
# check this until more platforms are tested.
if [ ! -e "/etc/debian_version" -a ! -e "/etc/redhat-release" ] ; then
    echo "-- Warning --"
    echo "You are running this script on an untested platform."
    echo "Please check the configured directory paths."
    exit 101
fi

# Should be run as a user, which is able to execute munin scripts
# as munin user.
if [ "`sudo -u munin echo`" ] ; then
    echo 'Cannot execute command, need sudo privileges for user munin: sudo -u munin echo'
    echo $?
    exit 102
fi


# Check if all directories are writeable by the current user.
if [ ! -w "${RRDDIR}"  ] ; then
    echo "Cannot write to RRD-Directory: ${RRDDIR}"
    exit 103
fi

if [ ! -w "${HTMLDIR}" ] ; then
    echo "Cannot write to HTML-Directory: ${HTMLDIR}"
    exit 104
fi


###### BACKUP DIRECTORY
if [ -e "$BACKDIR" ] ; then
   echo "E1 - Backup directory already exits."
   exit 105
fi

mkdir -p $BACKDIR

if [ ! -w $BACKDIR ] ; then
    echo "Cannot write to BACKUP-Directory: ${BACKDIR}"
    exit 106
fi



###### BACKUP RRD
echo "01 - Creating backup in ${BACKDIR}"

for i in `find $RRDDIR -iname "${HOST}-*.rrd"` ; do
    cp $i $BACKDIR
    check_rc "E1 - Cannot create backup of file.\ncp ${i} ${BACKDIR}"
done



###### RENAME
echo "02 - Renaming rrd files in: ${RRDDIR}"
for i in `find $RRDDIR -iname "${HOST}-*.rrd"` ; do
    new=`echo ${i}|sed -e "s/${HOST}/${HOSTNEW}/"`
    if [ -e $new ] ; then
        echo "Error: Won't move rrd file, destination already exits: ${new}"
        exit 107
    fi

    mv ${i} ${new}
    check_rc "E2 - Cannot move ${i} to ${new}."
done

##### DELETE HTML+IMAGES
echo "03 - Deleting old images and html files."
for i in `find ${HTMLDIR} -regextype posix-egrep -regex "${HTMLDIR}/${HOST}-.*(html|png)"` ; do
    rm ${i}
    check_rc "E3 - Cannot delete $i."
done

##### RUN MUNIN-UPDATE, MUNIN-GRAH AND MUNIN-HTML AS MUNIN USER
echo "04 - Running munin-graph for ${HOSTNEW}"
sudo -u munin /usr/share/munin/munin-update
check_rc "E4 - Cannot run munin-update as munin user (needs sudo privileges)."

echo "05 - Running munin-graph"
sudo -u munin /usr/share/munin/munin-graph --force --host ${HOSTNEW} --week --month --year
check_rc "E5 - Cannot run munin-graph as munin user (needs sudo privileges)."

echo "06 - Running munin-html"
sudo -u munin /usr/share/munin/munin-html 
check_rc "E6 - Cannot run munin-html as munin user (needs sudo privileges)."

###### SUCCESS
echo "Successfully renamed the host. New hostname: ${HOSTNEW}"