13.5.3. The syslog-ng pattern database format

Pattern databases are XML files that contain rules describing the message patterns. For sample pattern databases, see Section 13.2.2, Downloading sample pattern databases.

The following scheme describes the V5 format of the pattern database. This format is backwards-compatible with the earlier formats.

For a sample database containing only a single pattern, see Example 13.20, A pattern database containing a single rule.

Tip

Use the pdbtool utility that is bundled with syslog-ng to test message patterns and convert existing databases to the latest format. For details, see pdbtool(1).

To automatically create an initial pattern database from an existing log file, use the pdbtool patternize command. For details, see the section called “The patternize command”.

Example 13.20. A pattern database containing a single rule

The following pattern database contains a single rule that matches a log message of the ssh application. A sample log message looks like:

Accepted password for sampleuser from 10.50.0.247 port 42156 ssh2

The following is a simple pattern database containing a matching rule.

<patterndb version='5' pub_date='2010-10-17'>
    <ruleset name='ssh' id='123456678'>
        <pattern>ssh</pattern>
            <rules>
                <rule provider='me' id='182437592347598' class='system'>
                    <patterns>
                        <pattern>Accepted @QSTRING:SSH.AUTH_METHOD: @ for@QSTRING:SSH_USERNAME: @from\ @QSTRING:SSH_CLIENT_ADDRESS: @port @NUMBER:SSH_PORT_NUMBER:@ ssh2</pattern>
                    </patterns>
                </rule>
            </rules>
    </ruleset>
</patterndb>

Note that the rule uses macros that refer to parts of the message, for example, you can use the ${SSH_USERNAME} macro refer to the username used in the connection.

The following is the same example, but with a test message and test values for the parsers.

<patterndb version='4' pub_date='2010-10-17'>
    <ruleset name='ssh' id='123456678'>
        <pattern>ssh</pattern>
            <rules>
                <rule provider='me' id='182437592347598' class='system'>
                    <patterns>
                        <pattern>Accepted @QSTRING:SSH.AUTH_METHOD: @ for@QSTRING:SSH_USERNAME: @from\ @QSTRING:SSH_CLIENT_ADDRESS: @port @NUMBER:SSH_PORT_NUMBER:@ ssh2</pattern>
                    </patterns>
                    <examples>
                        <example>
                            <test_message>Accepted password for sampleuser from 10.50.0.247 port 42156 ssh2</test_message>
                            <test_values>
                                <test_value name="SSH.AUTH_METHOD">password</test_value>
                                <test_value name="SSH_USERNAME">sampleuser</test_value>
                                <test_value name="SSH_CLIENT_ADDRESS">10.50.0.247</test_value>
                                <test_value name="SSH_PORT_NUMBER">42156</test_value>
                            </test_values>
                       </example>
                    </examples>
                </rule>
            </rules>
    </ruleset>
</patterndb>