Munin::Plugin::Pgsql − Base module for PostgreSQL plugins for Munin
The Munin::Plugin::Pgsql module provides base functionality for all PostgreSQL Munin plugins, including common configuration parameters.
All configuration is done through environment variables.
All plugins based on Munin::Plugin::Pgsql accepts all the environment variables that libpq does. The most common ones used are:
PGHOST hostname to connect to, or path to Unix socket PGPORT port number to connect to PGUSER username to connect as PGPASSWORD password to connect with, if a password is required
The plugins will by default connect to the ’template1’ database, except for wildcard per-database plugins. This can be overridden using the PGDATABASE variable, but this is usually a bad idea.
[postgres_*] user postgres env.PGUSER postgres env.PGPORT 5433
Wildcard plugins based on this module will match on whatever type of object specifies for a filter, usually a database. If the object name ALL is used (for example, a symlink to postgres_connections_ALL), the filter will not be applied, and the plugin behaves like a non-wildcard one.
The module requires DBD::Pg to work.
Support for using psql instead of DBD::Pg, to remove dependency.
No known bugs at this point.
Magnus Hagander <magnus AT hagander DOT net>, Redpill Linpro AB
Copyright (c) 2009 Magnus Hagander, Redpill Linpro AB
All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 dated June, 1991.
The following functions are available to plugins using this module.
use Munin::Plugin::Pgsql; my $pg = Munin::Plugin::Pgsql−>new( parameter=>value, parameter=>value );
minversion Minimum PostgreSQL version required, formatted like 8.2. If the database is an older version than this, the plugin will exit with an error. category The category for this plugin. Copied directly to the config output. Default 'PostgreSQL'. title The title for this plugin. Copied directly to the config output. info The info for this plugin. Copied directly to the config output. vlabel The vertical label for the graph. Copied directly to the config output. basename For wildcard plugins, this is the base name of the plugin, including the trailing underscore. basequery SQL query run to get the plugin values. The query should return two columns, one being the name of the counter and the second being the current value for the counter. pivotquery Set to 1 to indicate that the query in basequery returns a single row, with one field for each counter. The name of the counter is taken from the returned column name, and the value from the first row in the result. configquery SQL query run to generate the configuration information for the plugin. The query should return at least two columns, which are the name of the counter and the label of the counter. If a third column is present, it will be used as the info parameter. suggestquery SQL query to run to generate the list of suggestions for a wildcard plugin. Don't forget to include ALL if the plugin supports aggregate statistics. autoconfquery SQL query to run as the last step of "autoconf", to determine if the plugin should be run on this machine. Must return a single row, two columns columns. The first one is a boolean field representing yes or no, the second one a reason for "no". graphdraw The draw parameter for the graph. The default is LINE1. graphtype The type parameter for the graph. The default is GAUGE. graphperiod The period for the graph. Copied directly to the config output. graphmin The min parameter for the graph. The default is no minimum. graphmax The max parameter for the graph. The default is no maximum. stack If set to 1, all counters except the first one will be written with a draw type of STACK. base Used for graph_args −−base. Default is 1000, set to 1024 when returning sizes in Kb for example. wildcardfilter The SQL to substitute for when a wildcard plugin is run against a specific entity, for example a database. All occurrances of the string %%FILTER%% will be replaced with this string, and for each occurance a parameter with the value of the filtering condition will be added to the DBI statement. paramdatabase Makes the plugin connect to the database in the first parameter (wildcard plugins only) instead of 'template1'. defaultdb Makes the plugin connect to the database specified in this parameter instead of 'template1'. extraconfig This string is copied directly into the configuration output when the plugin is run in config mode, allowing low−level customization. postprocess A function that's called with the result of the base query, and can post−process the result and return a new resultset. postconfig A function that's called with the result of the config query, and can post−process the result and return a new resultset. postautoconf A function that's called with the result of the autoconf query, and can post−process the result and return a new resultset. postsuggest A function that's called with the result of the suggest query, and can post−process the result and return a new resultset.
Queries specified in one of the parameters above can take one of two forms. The easiest one is a simple string, which will then always be executed, regardless of server version. The other form is an array, looking like this:
" SELECT ’default’,... FROM ...",
"8.3", " SELECT ’query for 8.3 or earlier’,... FROM ...",
"8.1", "SELECT ’query for 8.1 or earlier’,... FROM ..."
] This array is parsed from top to bottom, so the entries must be in order of version number. The *last* value found where the version specified is higher than or equal to the version of the server will be used (yes, it counts backwards).
$pg−>Process(); This command executes the plugin. It will automatically parse the ARGV array for commands given by Munin.