Struct syslog_tracing::Syslog

pub struct Syslog { /* private fields */ }

MakeWriter that logs to syslog via libc’s syslog() function.

Level Mapping

tracing Levels are mapped to syslog severities as follows:

Level::ERROR => Severity::LOG_ERR,
Level::WARN  => Severity::LOG_WARNING,
Level::INFO  => Severity::LOG_NOTICE,
Level::DEBUG => Severity::LOG_INFO,
Level::TRACE => Severity::LOG_DEBUG,

Note: the mapping is lossless, but the corresponding syslog severity names differ from tracing’s level names towards the bottom. syslog does not have a level lower than LOG_DEBUG, so this is unavoidable.

Examples

Initializing a global logger that writes to syslog with an identity of example-program and the default syslog options and facility:

let identity = std::ffi::CStr::from_bytes_with_nul(b"example-program\0").unwrap();
let (options, facility) = Default::default();
let syslog = syslog_tracing::Syslog::new(identity, options, facility).unwrap();
tracing_subscriber::fmt().with_writer(syslog).init();

Implementations

impl Syslog

pub fn new( identity: impl Into<Cow<'static, CStr>>, options: Options, facility: Facility ) -> Option<Self>

Creates a [tracing] MakeWriter that writes to syslog.

This calls libc::openlog() to initialize the logger. The corresponding libc::closelog() call happens when the returned logger is dropped. If a logger already exists, returns None.

Examples

Creating a syslog MakeWriter with an identity of example-program and the default syslog options and facility:

use syslog_tracing::Syslog;
let identity = std::ffi::CStr::from_bytes_with_nul(b"example-program\0").unwrap();
let (options, facility) = Default::default();
let syslog = Syslog::new(identity, options, facility).unwrap();

Two loggers cannot coexist, since libc::syslog() writes to a global logger:

let syslog = Syslog::new(identity, options, facility).unwrap();
assert!(Syslog::new(identity, options, facility).is_none());

pub fn invalid_chars(self, cfg: InvalidCharAction) -> Self

Set the action to take when a message cannot be logged as is because it contains invalid characters.

Trait Implementations

impl Drop for Syslog

fn drop(&mut self)

Calls libc::closelog().

impl<'a> MakeWriter<'a> for Syslog

type Writer = SyslogWriter

The concrete io::Write implementation returned by make_writer.

fn make_writer(&'a self) -> Self::Writer

Returns an instance of Writer.

fn make_writer_for(&'a self, meta: &Metadata<'_>) -> Self::Writer

Returns a Writer for writing data from the span or event described by the provided Metadata.