feat: add log to journald feature

Cargo.lock

@@ -1355,6 +1355,7 @@ dependencies = [
  "tokio",
  "toml",
  "tracing",
+ "tracing-journald",
  "tracing-subscriber",
 ]
 
@@ -4406,6 +4407,17 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "tracing-journald"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba316a74e8fc3c3896a850dba2375928a9fa171b085ecddfc7c054d39970f3fd"
+dependencies = [
+ "libc",
+ "tracing-core",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-log"
 version = "0.2.0"

Cargo.toml

@@ -79,6 +79,7 @@ pretty_env_logger = "0.5"
 structopt = { version = "0.3", default-features = false }
 syslog-tracing = "0.3"
 tracing = "0.1"
+tracing-journald = "0.3"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 
 heed = { version = "0.11", default-features = false, features = ["lmdb"] }

src/garage/Cargo.toml

@@ -60,6 +60,7 @@ opentelemetry-prometheus = { workspace = true, optional = true }
 opentelemetry-otlp = { workspace = true, optional = true }
 prometheus = { workspace = true, optional = true }
 syslog-tracing = { workspace = true, optional = true }
+tracing-journald = { workspace = true, optional = true }
 
 [dev-dependencies]
 aws-config.workspace = true
@@ -100,6 +101,8 @@ metrics = [ "garage_api/metrics", "opentelemetry-prometheus", "prometheus" ]
 telemetry-otlp = [ "opentelemetry-otlp" ]
 # Logging to syslog
 syslog = [ "syslog-tracing" ]
+# Logging to journald
+journald = [ "tracing-journald" ]
 
 # NOTE: bundled-libs and system-libs should be treat as mutually exclusive;
 # exactly one of them should be enabled.

src/garage/main.rs

@@ -208,6 +208,36 @@ fn init_logging(opt: &Opt) {
 		}
 	}
 
+	if std::env::var("GARAGE_LOG_TO_JOURNALD")
+		.map(|x| x == "1" || x == "true")
+		.unwrap_or(false)
+	{
+		#[cfg(feature = "journald")]
+		{
+			use tracing_subscriber::layer::SubscriberExt;
+			use tracing_subscriber::util::SubscriberInitExt;
+
+			let registry = tracing_subscriber::registry()
+				.with(tracing_subscriber::fmt::layer().with_writer(std::io::sink))
+				.with(env_filter);
+			match tracing_journald::layer() {
+				Ok(layer) => {
+					registry.with(layer).init();
+				}
+				Err(e) => {
+					eprintln!("Couldn't connect to journald: {}.", e);
+					std::process::exit(1);
+				}
+			}
+			return;
+		}
+		#[cfg(not(feature = "journald"))]
+		{
+			eprintln!("Journald support is not enabled in this build.");
+			std::process::exit(1);
+		}
+	}
+
 	tracing_subscriber::fmt()
 		.with_writer(std::io::stderr)
 		.with_env_filter(env_filter)