systemd-journal-logger

A pure Rust log logger for the systemd journal.

Usage

$ cargo add systemd-journal-logger

Then initialize the logger at the start of main:

use log::{info, warn, error, LevelFilter};
use systemd_journal_logger::JournalLog;

JournalLog::new().unwrap().install().unwrap();
log::set_max_level(LevelFilter::Info);

info!("hello log");
warn!("warning");
error!("oops");

You can also add additional fields to every log message, such as the version of your executable:

use log::{info, warn, error, LevelFilter};
use systemd_journal_logger::JournalLog;

JournalLog::new()
    .unwrap()
    .with_extra_fields(vec![("VERSION", env!("CARGO_PKG_VERSION"))])
    .with_syslog_identifier("foo".to_string())
    .install().unwrap();
log::set_max_level(LevelFilter::Info);

info!("this message has an extra VERSION field in the journal");

These extra fields appear in the output of journalctl --output=verbose or in any of the JSON output formats of journalctl.

See systemd_service.rs for a simple example of logging in a systemd service which automatically falls back to a different logger if not started through systemd.

Related projects

• rust-systemd provides a logger implementation based on the libsystemd C library.
• slog-journald provides an slog logger for the systemd journal, also based on the libsystemd C library.
• tracing-journald provides a tracing backend for the systemd journal, in a pure Rust implementation.

Both loggers use mostly the same fields and priorities as this implementation.

License

Either MIT or Apache 2.0, at your option.