Journalctl

This is a module for accessing the all mighty Systemd Journal and its handy dandy key-value store hidden behind every log line. In the background it spawns a journalctl process with the output format json and parses the serialised object stream.

API

Require the module and create a new instance:

const Journalctl = require('journalctl');
const journalctl = new Journalctl([opts]);

The optional object opts can have the following properties:

• identifier: Just output logs of the given syslog identifier (cf. man journalctl, option '-t')
• unit: Just output logs originated from the given unit file (cf. man journalctl, option '-u')
• filter: An array of matches to filter by (cf. man journalctl, matches)
• all: Show all fields in full, even if they include unprintable characters or are very long. (cf. man journalctl, option '-a')
• lines: Show the most recent journal events and limit the number of events shown (cf. man journalctl, option '-n')
• since: Start showing entries on or newer than the specified date (cf. man journalctl, option '-S')
• until: Stop showing entries on or older than the specified date (cf. man journalctl, option '-U')
• utc: Print timestamps in Coordinated Universal Time (UTC) (cf. man journalctl, option '--utc')
• output: Specify the output format (cf. man journalctl, option '-o')
• Supported formats: 'json', 'json-pretty', 'short', 'short-iso', 'short-monotonic', 'verbose', 'export', 'json-sse'

Event: 'event'

journalctl.on('event', (event) => {});

Is fired on every log event and hands over the object event describing the event. (Oh boy ... so many events in one sentence ...)

Method: stop

journalctl.stop([callback]);

Stops journalctl and calls the optional callback once everything has been killed.