Use fmt writer for systemd

This uses a custom fmt writer for systemd output to preserve all
information within the message field.

Signed-off-by: Sascha Grunert <[email protected]>

conmon-rs/server/Cargo.toml

@@ -28,7 +28,6 @@ strum = { version = "0.24.1", features = ["derive"] }
 shadow-rs = "=0.16.1"
 multimap = "0.8.3"
 tracing = "0.1.36"
-tracing-journald = "0.3.0"
 tracing-subscriber = "0.3.15"
 uuid = { version = "1.1.2", features = ["v4", "fast-rng", "macro-diagnostics"] }
 regex = "1.6.0"
@@ -37,6 +36,7 @@ tokio-eventfd = "0.2.0"
 lazy_static = "1.4.0"
 tz-rs = "0.6.14"
 tokio-fd = "0.3.0"
+libsystemd = "0.5.0"
 
 [build-dependencies]
 shadow-rs = "=0.16.1"

conmon-rs/server/src/journal.rs

@@ -0,0 +1,35 @@
+use libsystemd::logging::{journal_print, Priority};
+use std::{
+    io::{self, Error, ErrorKind, Write},
+    str,
+};
+use tracing_subscriber::fmt::writer::MakeWriter;
+
+macro_rules! io_err {
+    ($x:expr) => {
+        $x.map_err(|e| Error::new(ErrorKind::Other, e.to_string()))?
+    };
+}
+
+#[derive(Default)]
+pub struct Journal;
+
+impl Write for Journal {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let s = io_err!(str::from_utf8(buf));
+        io_err!(journal_print(Priority::Notice, s));
+        Ok(s.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a> MakeWriter<'a> for Journal {
+    type Writer = Journal;
+
+    fn make_writer(&'a self) -> Self::Writer {
+        Journal::default()
+    }
+}

conmon-rs/server/src/lib.rs

@@ -9,6 +9,7 @@ mod container_io;
 mod container_log;
 mod cri_logger;
 mod init;
+mod journal;
 mod listener;
 mod oom_watcher;
 mod rpc;