UNIX and Linux lastlog logs: Reduce log size and convert to TSV format¶

Disclaimer

By using SPL2 templates for data processing (the “templates”), you understand and agree that templates are provided “as is”. Splunk disclaims any and all warranties, express or implied, including without limitation the implied warranties of merchantability, fitness for a particular purpose and warranties arising out of course of dealing or usage of trade or by statute or in law. Splunk specifically does not warrant that templates will meet your requirements, the operation or output of templates will be error-free, accurate, reliable, complete or uninterrupted.

Use case¶

Reduce the size of Unix and Linux lastlog logs by converting them to tab-separated values (TSV) format and optionally updating the source and sourcetype fields. This helps optimize log storage while maintaining compatibility with the Splunk Common Information Model (CIM).

Version 0.2.0¶

Version 0.2.0 of the UNIX and Linux lastlog logs: Reduce log size and convert to TSV format template was released on November 13, 2024.

Template details¶

Compatibility¶

This template is compatible with Splunk Add-on for Unix and Linux v9.2.0 and v10.0.0.

Template description¶

This is a sample pipeline that reduces the size of lastlog logs coming from the Splunk Add-on for Unix and Linux while preserving compatibility with the Splunk Common Information Model (CIM). This pipeline processes data with the lastlog source type and performs the following:

Converts the logs to TSV format by replacing repeated space characters with a tab character (\t).
Optionally updates the values of the source and sourcetype event fields.

Supported sourcetype¶

This pipeline only works on complete lastlog events that include the header row and all subsequent rows.

Template outline¶

The template consists of several custom functions followed by a pipeline that uses these functions.

Functions¶

The following table shows all functions, including possible configuration options.

Function name	Description	Configuration options
`replace_multiple_whitespaces`	Replaces repeated space characters in the logs with a single tab character (`\t`) or a custom delimiter.	`$delimiter`: The replacement delimiter to use instead of repeated space characters (default: `\t`).
`update_source_and_source_type`	Appends a suffix to the values in the `source` and `sourcetype` fields, if those fields exist in the event.	`$suffix`: The suffix to append to the `source` and `sourcetype` values.

Pipeline¶

This pipeline has the following outline:

Replaces repeated space characters with tabs using the replace_multiple_whitespaces function.
Optionally updates the source and sourcetype fields using the update_source_and_source_type function.
Sends the transformed logs to the destination.

Configuration instructions¶

Use the update_source_and_source_type function to append a suffix to the source and sourcetype fields. This helps distinguish modified logs from unmodified ones. The source and sourcetype fields must already exist in the event before you use this function.

Notes¶

Ensure that the lastlog source type is properly configured in your Splunk deployment.
Customize the pipeline as needed to meet your specific requirements.
If using the update_source_and_source_type function, ensure that the suffixed source type is configured in your Splunk platform deployment with appropriate time extraction and line-breaking settings.