add log format control

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "highlights"
-version = "2.1.1"
+version = "2.1.2"
 authors = ["ThatsNoMoon <git@thatsnomoon.dev>"]
 repository = "https://github.com/ThatsNoMoon/highlights"
 license = "OSL-3.0"
@@ -43,7 +43,7 @@ serde_json = { version = "1.0", optional = true }
 tinyvec = { version = "1.5", features = ["alloc"] }
 tracing = "0.1"
 tracing-opentelemetry = { version = "0.17", optional = true }
-tracing-subscriber = "0.3"
+tracing-subscriber = { version = "0.3", features = ["json"] }
 
 [dependencies.config]
 version = "0.13"

example_config.toml

@@ -26,6 +26,8 @@ sample_ratio = 1.0
 level = "WARN"
 # Whether or not to use ANSI color codes (may not work on Windows)
 color = true
+# Format of standard output logging (can be "compact", "pretty", or "json")
+format = "compact"
 [logging.filters]
 # The `highlights` crate will log at INFO instead
 highlights = "INFO"

src/logging/mod.rs

@@ -6,14 +6,15 @@
 use anyhow::Result;
 #[cfg(any(feature = "monitoring", feature = "reporting"))]
 use tracing::warn;
-use tracing::Metadata;
+use tracing::{Metadata, Subscriber};
 use tracing_subscriber::{
 	filter::FilterFn,
-	layer::{Layer, SubscriberExt},
+	layer::{Layer, Layered, SubscriberExt},
+	registry::LookupSpan,
 	util::SubscriberInitExt,
 };
 
-use crate::settings::{settings, Settings};
+use crate::settings::{settings, LogFormat, Settings};
 
 #[cfg(feature = "monitoring")]
 mod monitoring;
@@ -49,38 +50,61 @@ fn use_filters(settings: &Settings, metadata: &Metadata) -> bool {
 /// This initializes [`reporting`] and [`monitoring`], if
 /// enabled, as well as basic stdout logging.
 pub(crate) fn init() -> Result<()> {
-	let subscriber = tracing_subscriber::registry().with(
-		tracing_subscriber::fmt::layer()
-			.with_ansi(settings().logging.color)
-			.with_filter({
-				let settings = settings();
-				FilterFn::new(|metadata| use_filters(settings, metadata))
-			}),
-	);
+	let fmt =
+		tracing_subscriber::fmt::layer().with_ansi(settings().logging.color);
 
-	#[cfg(feature = "monitoring")]
-	let (is_monitoring, subscriber) = {
-		let layer = monitoring::init()?;
-		(layer.is_some(), subscriber.with(layer))
+	let filter = {
+		let settings = settings();
+		FilterFn::new(|metadata| use_filters(settings, metadata))
 	};
 
-	#[cfg(feature = "reporting")]
-	let (is_reporting, subscriber) = {
-		let layer = reporting::init();
-		(layer.is_some(), subscriber.with(layer))
-	};
+	fn init_rest<L, S>(subscriber: Layered<L, S>) -> Result<()>
+	where
+		L: Layer<S> + Send + Sync + 'static,
+		S: Subscriber + for<'span> LookupSpan<'span> + Send + Sync + 'static,
+	{
+		#[cfg(feature = "monitoring")]
+		let (is_monitoring, subscriber) = {
+			let layer = monitoring::init()?;
+			(layer.is_some(), subscriber.with(layer))
+		};
 
-	subscriber.try_init()?;
+		#[cfg(feature = "reporting")]
+		let (is_reporting, subscriber) = {
+			let layer = reporting::init();
+			(layer.is_some(), subscriber.with(layer))
+		};
 
-	#[cfg(feature = "monitoring")]
-	if !is_monitoring {
-		warn!("Jaeger agent address not provided; not reporting traces");
-	}
+		subscriber.try_init()?;
+
+		#[cfg(feature = "monitoring")]
+		if !is_monitoring {
+			warn!("Jaeger agent address not provided; not reporting traces");
+		}
 
-	#[cfg(feature = "reporting")]
-	if !is_reporting {
-		warn!("Webhook URL is not present, not reporting panics");
+		#[cfg(feature = "reporting")]
+		if !is_reporting {
+			warn!("Webhook URL is not present, not reporting panics");
+		}
+
+		Ok(())
 	}
 
-	Ok(())
+	match &settings().logging.format {
+		LogFormat::Compact => {
+			let subscriber = tracing_subscriber::registry()
+				.with(fmt.compact().with_filter(filter));
+			init_rest(subscriber)
+		}
+		LogFormat::Pretty => {
+			let subscriber = tracing_subscriber::registry()
+				.with(fmt.pretty().with_filter(filter));
+			init_rest(subscriber)
+		}
+		LogFormat::Json => {
+			let subscriber = tracing_subscriber::registry()
+				.with(fmt.json().with_filter(filter));
+			init_rest(subscriber)
+		}
+	}
 }

src/settings.rs

@@ -196,6 +196,51 @@ mod level {
 }
 
 use level::{deserialize_level_filter, deserialize_level_filters};
+
+mod log_format {
+	use std::fmt;
+
+	use serde::{de, Deserialize, Deserializer};
+
+	#[derive(Debug)]
+	pub(crate) enum LogFormat {
+		Compact,
+		Pretty,
+		Json,
+	}
+
+	/// Visitor to deserialize a `LevelFilter` from a string.
+	struct LogFormatVisitor;
+	impl<'de> de::Visitor<'de> for LogFormatVisitor {
+		type Value = LogFormat;
+		fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+			write!(formatter, "a log format (compact, pretty, json)")
+		}
+
+		fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+		where
+			E: de::Error,
+		{
+			match v {
+				"compact" | "COMPACT" => Ok(LogFormat::Compact),
+				"pretty" | "PRETTY" => Ok(LogFormat::Pretty),
+				"json" | "JSON" => Ok(LogFormat::Json),
+				_ => Err(E::invalid_value(de::Unexpected::Str(v), &self)),
+			}
+		}
+	}
+
+	impl<'de> Deserialize<'de> for LogFormat {
+		fn deserialize<D>(d: D) -> Result<Self, D::Error>
+		where
+			D: Deserializer<'de>,
+		{
+			d.deserialize_str(LogFormatVisitor)
+		}
+	}
+}
+
+pub(crate) use log_format::LogFormat;
 #[cfg(feature = "monitoring")]
 pub(crate) use user_address::UserAddress;
 
@@ -259,6 +304,8 @@ pub(crate) struct LoggingSettings {
 
 	/// Whether or not to use ANSI color codes.
 	pub(crate) color: bool,
+	/// Standard output logging format.
+	pub(crate) format: LogFormat,
 }
 
 /// Settings for the database.