chrisberkhout / graphital

A simple ruby daemon to send host vitals to graphite

Graphital

Find Rashid Khan (rashidkpc) in #logstash.

Graphital is a very simple (~50 lines) ruby daemon for shipping system vitals to Graphite. It uses a graphital.d directory and simply runs everything in it. Several examples are included (most require the sar utility from the sysstat package), but its easy to write your own in your language of choice. If you write something particularly useful, please do share. Scripts should output in the format:

metric #

For example, to track cpu % you might create a file called graphital.d/cpu.rb and it might output (to stdout):

user 18  
idle 80  
iowait 2  

Graphital will prepend the $PREFIX you set in graphital.conf (by default this includes %x(hostname).chomp to prepend the hostname) and the name of the script before the first .. The above example might create a metric like hostname1.cpu.user. Scripts must complete in less than your specified $INTERVAL (60s by default) or they will be terminated.

Requirements

• Ruby >= 1.8.7 (probably?)
• daemons gem (or an alternate daemonization strategy)

Use

Install

git clone https://github.com/rashidkpc/graphital.git /opt/graphital
cd /opt/graphital
gem install daemons

Configure

There is an example configuration file called graphital.conf.eg (that will be loaded if nothing else is found). You should create your own configuration file at /etc/graphital.conf or /opt/graphital/graphital.conf.

Make sure you set your Graphite server address in your graphital.conf:

$HOST = 'graphite.example.com'

Run using daemons gem

This will invoke graphital.rb and put it into the background.

ruby /opt/graphital/daemon.rb start  

Run as a service using Upstart (e.g. on Ubuntu or Fedora)

Rather than using the daemons gem, you can run graphital.rb directly, and use another method for making it a service that can be started, tracked and stopped.

On systems using Upstart, this is as easy as adding a /etc/init/graphital.conf file like:

description     "send system vitals to graphite"

start on runlevel [2345]
stop on runlevel [!2345]

respawn

exec /usr/bin/ruby /opt/graphital/graphital.rb

Try it out with:

service graphital start
service graphital status
service graphital restart