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 [http://visage.unstated.net/nadia/cpu+load] (a demo).

Dependencies

Ruby (install with gem install <dep>:

• bundler08

Please note Visage uses bundler08 not bundler. Current bundler releases depend on a version of RubyGems that is not packaged on any recent stable Linux distribution.

System (install with your system's package manager):

• git, librrd-dev, ruby, rubygems, librrd-ruby

Installing

Check out the code from GitHub:

$ git clone git://github.com/auxesis/visage.git

Bundle dependencies:

$ gem bundle

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).

all the config/*-profiles.yaml are automatically glob-ed in. You can easily do a per host profiles file this way.

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.

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.

Samples for config files :

Example of config/groups.yaml : --- infra: fluor magnesium

services:
  uranium
  azote

Example of config/sets.yaml : --- databases: graphs: - mysqlnode1: - cpu-0 - mysqlnode2: - cpu-0 - mysqlpra: - cpu-0 www-related: graphs: - carbone: - interface - fluor: - interface - magnesium: - interface - mazerati: - interface - nginx