Install and configure Prometheus Node Exporter on a CentOS 6 box

install_node_exporter.centos6.sh

#!/bin/bash

# Install Prometheus Node Exporter on CentOS 6.

set -eu
set -o pipefail
set -x

REPOFILE='/etc/yum.repos.d/coprs.ibotty.prometheus-exporters.repo'
INSTALLED=0

if test -f "$REPOFILE"; then
  INSTALLED=1
  service node_exporter stop || true
fi

if [[ $INSTALLED -eq 0 ]]; then
  curl -sS https://copr.fedorainfracloud.org/coprs/ibotty/prometheus-exporters/repo/epel-6/ibotty-prometheus-exporters-epel-6.repo > $REPOFILE
  # this will create the node_exporter user / group
  yum install node_exporter
  iptables -I INPUT -p tcp --dport 9100 -j ACCEPT
  service iptables save
fi

touch /var/log/node_exporter.log
chmod 640 /var/log/node_exporter.log
chown node_exporter:adm /var/log/node_exporter.log

# Adjust permissions slightly from what the repo provided.
chown root:node_exporter /var/lib/node_exporter/textfile_collector/
chmod 2771 /var/lib/node_exporter/textfile_collector/


cat << 'EOF' > /etc/logrotate.d/node_exporter
/var/log/node_exporter.log {
  weekly
  missingok
  notifempty
  compress
  delaycompress
  create 640 node_exporter adm
}
EOF

cat << 'EOF' > /etc/init.d/node_exporter
#!/bin/bash
#
# node_exporter Export statistics to be consumed by a remote Prometheus server
#
# chkconfig: 345 70 30
# description: Prometheus node exporter
# processname: node_exporter
### BEGIN INIT INFO
# Provides:
# Required-Start:
# Required-Stop:
# Default-Start: 3 4 5
# Default-Stop: 0 1 2 6
### END INIT INFO

#
#
#  Prometheus node exporter
#  /etc/init.d/node_exporter
#
#


# Source function library.
. /etc/init.d/functions

PROGNAME=node_exporter
PROG=/usr/sbin/$PROGNAME
USER=node_exporter
LOGFILE=/var/log/node_exporter.log
LOCKFILE=/var/run/$PROGNAME.pid

start() {
    echo -n "Starting $PROGNAME: "
    cd /var/lib/node_exporter/textfile_collector/
    daemon --user $USER --pidfile="$LOCKFILE" "$PROG &>$LOGFILE &"
    echo $(pidofproc $PROGNAME) >$LOCKFILE
    echo
}

stop() {
    echo -n "Shutting down $PROGNAME: "
    killproc $PROGNAME
    rm -f $LOCKFILE
    echo
}


case "$1" in
    start)
    start
    ;;
    stop)
    stop
    ;;
    status)
    status $PROGNAME
    ;;
    restart)
    stop
    start
    ;;
    reload)
    echo "Sending SIGHUP to $PROGNAME"
    kill -SIGHUP $(pidofproc $PROGNAME)#!/bin/bash
    ;;
    *)
        echo "Usage: service node_exporter {start|stop|status|reload|restart}"
        exit 1
    ;;
esac
EOF

chmod 755 /etc/init.d/node_exporter

if [[ $INSTALLED -eq 0 ]]; then
  chkconfig node_exporter --add
fi

service node_exporter start