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diff --git a/doc/rsyslog_conf_modules.html b/doc/rsyslog_conf_modules.html index a4c8c423..805894e7 100644 --- a/doc/rsyslog_conf_modules.html +++ b/doc/rsyslog_conf_modules.html @@ -2,11 +2,50 @@ <html><head><title>Modules - rsyslog.conf</title></head> <body> <p>This is a part of the rsyslog.conf documentation.</p> -<a href="rsyslog_conf.html">back</a> -<h2>Modules</h2> -<p>Rsyslog has a modular design. Consequently, there is a growing +<a href="rsyslog_conf.html">Back to rsyslog.conf manual</a> +<h1>Modules</h1> +<p>Rsyslog has a modular design. This enables functionality to be +dynamically loaded from modules, which may also be written by any +third party. Rsyslog itself offers all non-core functionality as +modules. Consequently, there is a growing number of modules. Here is the entry point to their documentation and what they do (list is currently not complete)</p> +<p>Please note that each module provides configuration +directives, which are NOT necessarily being listed below. Also +remember, that a modules configuration directive (and functionality) is +only available if it has been loaded (using $ModLoad).</p> +<p>It is relatively easy to write a rsyslog module. <b>If none of the provided +modules solve your need, you may consider writing one or have one written +for you by +<a href="http://www.rsyslog.com/professional-services">Adiscon's professional services for rsyslog</a> +</b>(this often is a very cost-effective and efficient way of getting what you need). +<p>There exist different classes of loadable modules: +<ul> +<li><a href="rsyslog_conf_modules.html#im">Input Modules</a> +<li><a href="rsyslog_conf_modules.html#om">Output Modules</a> +<li><a href="rsyslog_conf_modules.html#pm">Parser Modules</a> +<li><a href="rsyslog_conf_modules.html#mm">Message Modification Modules</a> +<li><a href="rsyslog_conf_modules.html#lm">Library Modules</a> +</ul> + +<a name"im"></a><h2>Input Modules</h2> +<p>Input modules are used to gather messages from various sources. They interface +to message generators. +<ul> +<li><a href="imfile.html">imfile</a> - input module for text files</li> +<li><a href="imrelp.html">imrelp</a> - RELP input module</li> +<li>imudp - udp syslog message input</li> +<li><a href="imtcp.html">imtcp</a> - input plugin for plain tcp syslog</li> +<li><a href="imgssapi.html">imgssapi</a> - input plugin for plain tcp and GSS-enabled syslog</li> +<li>immark - support for mark messages</li> +<li><a href="imklog.html">imklog</a> - kernel logging</li> +<li><a href="imuxsock.html">imuxsock</a> - unix sockets, including the system log socket</li> +<li><a href="im3195.html">im3195</a> - accepts syslog messages via RFC 3195</li> +</ul> + +<a name"om"></a><h2>Output Modules</h2> +<p>Output modules process messages. With them, message formats can be transformed +and messages be transmitted to various different targets. <ul> <li><a href="omsnmp.html">omsnmp</a> - SNMP trap output module</li> <li><a href="omstdout.html">omtdout</a> - stdout output module (mainly a test tool)</li> @@ -22,26 +61,53 @@ SQLLite, Ingres, Oracle, mSQL)</li> permits rsyslog to alert folks by mail if something important happens</li> <li><a href="omoracle.html">omoracle</a> - output module for Oracle (native OCI interface)</li> <li><a href="omudpspoof.html">omudpspoof</a> - output module sending UDP syslog messages with a spoofed address</li> -<li><a href="imfile.html">imfile</a> -- input module for text files</li> -<li><a href="imrelp.html">imrelp</a> - RELP -input module</li> -<li><a href="imudp.html">imudp</a> - udp syslog message input</li> -<li><a href="imtcp.html">imtcp</a> - input -plugin for plain tcp syslog</li> -<li><a href="imgssapi.html">imgssapi</a> - -input plugin for plain tcp and GSS-enabled syslog</li> -<li>immark - support for mark messages</li> -<li><a href="imklog.html">imklog</a> - kernel logging</li> -<li><a href="imuxsock.html">imuxsock</a> - -unix sockets, including the system log socket</li> -<li><a href="im3195.html">im3195</a> - -accepts syslog messages via RFC 3195</li> </ul> -<p>Please note that each module provides configuration -directives, which are NOT necessarily being listed below. Also -remember, that a modules configuration directive (and functionality) is -only available if it has been loaded (using $ModLoad).</p> + +<a name="pm"></a><h2>Parser Modules</h2> +<p>Parser modules are used to parse message content, once the message has been +received. They can be used to process custom message formats or invalidly formatted +messages. For details, please see the <a href="rsyslog_messageparser.html">rsyslog +message parser documentation</a>. +<p>The current modules are currently provided as part of rsyslog: +<ul> +<li>pmrfc5424 - parses RFC5424-formatted messages (the new syslog standard) +<li>pmrfc3164 - the traditional/legacy syslog parser +</ul> + +<a name="mm"></a><h2>Message Modification Modules</h2> +<p>Message modification modules are used to change the content of messages being processed. +They can be implemented using either the output module or the parser module interface. +From the rsyslog core's point of view, they actually are output or parser modules, it is their +implementation that makes them special. +<p>Currently, there do not exist any such modules, but could be written with +the methods the engine provides. They could be used, for example, to: +<ul> +<li>anonymize message content +<li>add dynamically computed content to message (fields) +</ul> + +<a name="lm"></a><h2>Library Modules</h2> +<p>Library modules provide dynamically loadable functionality for parts of rsyslog, +most often for other loadable modules. They can not be user-configured and are loaded +automatically by some components. They are just mentioned so that error messages that +point to library moduls can be understood. No module list is provided. + +<h2>Where are the modules integrated into the Message Flow?</h2> +<p>Depending on their module type, modules may access and/or modify messages at +various stages during rsyslog's processing. Note that only the "core type" (e.g. input, +output) but not any type derived from it (message modification module) specifies when +a module is called. +<p>The simplified workflow is as follows: +<p align="center"> +<img src="module_workflow.png" alt"rsyslog: loadable modules and message flow"> +<p>As can be seen, messages are received by input modules, then passed to one or many +parser modules, which generate the in-memory representation of the message and may +also modify the message itself. The, the internal representation is passed to +output modules, which may output a message and (with the interfaces newly introduced +in v5) may also modify messageo object content. +<p>Note that the actual flow is much more complex and depends a lot on queue and +filter settings. This graphic above is a high-level message flow diagram. + <p>[<a href="manual.html">manual index</a>] [<a href="rsyslog_conf.html">rsyslog.conf</a>] [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p> |