NAME

       Munin::Plugin::Pgsql - Base module for PostgreSQL plugins for Munin

SYNOPSIS

       The Munin::Plugin::Pgsql module provides base functionality for all PostgreSQL Munin
       plugins, including common configuration parameters.

CONFIGURATION

       All configuration is done through environment variables.

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.

   Example
        [postgres_*]
           user postgres
           env.PGUSER postgres
           env.PGPORT 5433

WILDCARD MATCHING

       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.

REQUIREMENTS

       The module requires DBD::Pg to work.

TODO

       Support for using psql instead of DBD::Pg, to remove dependency.

BUGS

       No known bugs at this point.

SEE ALSO

       DBD::Pg

AUTHOR

       Magnus Hagander <magnus@hagander.net>, Redpill Linpro AB

COPYRIGHT/License.

       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.

API DOCUMENTATION

       The following functions are available to plugins using this module.

   Initialization
        use Munin::Plugin::Pgsql;
        my $pg = Munin::Plugin::Pgsql->new(
           parameter=>value,
           parameter=>value
        );

       Parameters

        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.

       Specifying queries

       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).

   Processing
        $pg->Process();

        This command executes the plugin. It will automatically parse the ARGV array
        for commands given by Munin.