go-journalctl

Go parser for systemd journal log files.

The format is documented here https://systemd.io/JOURNAL_FILE_FORMAT/

This parser is written in pure Go (rather than binding the system C libraries) which makes it portable to other operating systems.

Reading a journal file

To dump a journal file use the cat command:

./go-journalctl cat /run/log/journal/4e7cbddbe9494fb9876af4e3e85c9eb4/system.journal

To follow for new entries use the -f flag

./go-journalctl cat -f /run/log/journal/4e7cbddbe9494fb9876af4e3e85c9eb4/system.journal

Parsed VS. raw logs.

Internally systemd treats all entries as being strings, but many entries are integers or timestamps. By default go-journalctl will parse the events based on known event fields into two groups:

1. The System group contains trusted fields added by the System and not settable by the logging client.
2. The EventData field is free form and contains arbitrary fields and values set by the logging client.

This scheme is similar to the Windows event log scheme and makes it eaiser to insert the data into structuted storage and perform structured queries on the data.

If you wish to see the original raw event fields, set the --raw flag.