Visage

Visage is a web interface for viewing collectd statistics.

It also provides a JSON interface onto collectd's RRD data, giving you an easy way to mash up the data.

Features

• renders graphs in the browser, and retrieves data asynchronously
• interactive graph keys, to highlight lines and toggle line visibility
• drop-down or mouse selection of timeframes (also rendered asynchronously)
• JSON interface onto collectd RRDs

Check out a demo at http://visage.unstated.net/.

Installing

Bundle dependencies:

$ bundle install vendor/gems/

Amongst other things, this will pull in Errand, which requires the rrdtool headers to build a C extension. On Debian/Ubuntu these are in the librrd2-dev package, and on RHEL/CentOS rrdtool-devel.

Configuring

Config lives in several files under config/.

• profiles.yaml - groups of graphs Visage is to display
• plugin-colors.yaml - colors for specific plugins/plugin instances
• fallback-colors.yaml - ordered list of fallback colors
• init.rb - bootstrapping code, specifies collectd's RRD directory

profiles.yaml isn't setup by default, but you can copy profiles.yaml.sample across and edit to taste. The plugins are in the format of plugin/plugin-instance, with plugins-instance being optional.

If you don't specify a plugin-instance Visage will attempt to graph all plugin instances under the specified plugin, e.g. cpu-0 will display cpu-idle, cpu-interrupt, cpu-nice, etc, whereas cpu-0/cpu-wait will only show cpu-wait. You can also choose a specific group of plugin instances to graph, with something like cpu-0/cpu-system/cpu-user/cpu-wait.

It should be pretty easy to deduce the config format from the existing file (it's simple nested key-value data).

Make sure collectd's RRD directory is readable by whatever user the web server is running as. You can specify where collectd's rrd directory is in init.rb, with the c['rrddir'] key.

Developing

For development:

$ gem install shotgun
$ shotgun visage.rb

Deploying

With Passenger, create an Apache vhost with the DocumentRoot set to the public/ directory of where you have deployed the checked out code, e.g.

<VirtualHost *>
  ServerName visage.example.org
  ServerAdmin contact@visage.example.org

  DocumentRoot /srv/www/visage.example.org/root/public/

  <Directory "/srv/www/visage.example.org/root/public/">
     Options FollowSymLinks Indexes
     AllowOverride None
     Order allow,deny
     Allow from all 
   </Directory>

   ErrorLog /srv/www/visage.example.org/log/apache_errors_log
   CustomLog /srv/www/visage.example.org/log/apache_app_log combined

</VirtualHost>

This assumes you have a checkout of the code at /srv/www/visage.example.org/root.

If you don't want to use Apache + Passenger, you can install the thin or mongrel gems and run up a web server yourself.

Ubuntu users looking for Passenger packages should add John Ferlito's mod-passenger PPA to their apt sources.

Testing

Run all cucumber features:

$ rake cucumber 

Specific features:

$ bin/cucumber --require features/ features/something.feature

TODO

• create proper mootools class - DONE
• switch to g.raphael - DONE
• config file - DONE
• data profiles - DONE
• handle single plugin instance in graphing code - DONE
• specify data url in graphing code - DONE
• generate holders for graph/labels/time selector - DONE
• clean up routes - DONE
• smart colour selection (CPU-1 = CPU) - DONE
• title attributes - DONE
• split profiles + colors => plugins into separate files - DONE
• fix key labels - DONE
• axis labels (with human readable times) - DONE
• detailed point-in-time data on hover
• embedded html generator - DONE
• zoom + dynamic resize - DONE
• combine graphs from different hosts
• comment on time periods
• view list of comments
• provide option to shade under graphs - DONE
• interface to build custom graph profiles