Currently logs via systemd look like this:
Mar 08 13:13:10 appserv1 filebeat[22055]: 2022-03-08T13:13:10.657+0100 INFO instance/beat.go:694 Beat ID: 70152ff2-5b2e-4c03-a60c-eedffb110c54
and the timestamp is doubled. There should be option to run it without the timestamp, either via CLI option or autodetection (IIRC systemd sets few environmental variables like JOURNAL_STREAM and INVOCATION_ID so it could change format string based on that). In my code I used
if os.Getenv("INVOCATION_ID") != "" || os.Getenv("JOURNAL_STREAM") != "" {
consoleEncoderConfig.TimeKey = ""
}
(for go.uber.org/zap) with good success.