Create a separate logging section in config.

CONTRIBUTING.md

@@ -101,7 +101,7 @@ To do so, we will launch arti independently from Tor Browser. Build arti with
 `cargo build --release`.  After that launch it with some basic
 configuration parameters:
 
-    $ ./target/release/arti -c "socks_port = 9150" -c "trace_filter = 'debug'"
+    $ ./target/release/arti -c "socks_port = 9150" -c "logging.trace_filter = 'debug'"
 
 This will ensure that arti sets its SOCKS port on 9150. Now we need to launch
 Tor Browser and instruct it to use that SOCKS port.

crates/arti/src/arti_defaults.toml

@@ -6,8 +6,10 @@
 # Note that only one process can listen on a given port at a time.
 socks_port = 9150
 
-# Enable logging to journald where available
+# Configure logging
+[logging]
 
+# Enable logging to journald where available
 journald = false
 
 # Specify filtering directives for tracing.

crates/arti/src/main.rs

@@ -126,6 +126,20 @@ const ARTI_DEFAULTS: &str = concat!(
     include_str!("./authorities.toml"),
 );
 
+/// Structure to hold our logging configuration options
+#[derive(Deserialize, Debug, Clone)]
+#[serde(deny_unknown_fields)]
+struct LoggingConfig {
+    /// Filtering directives that determine tracing levels as described at
+    /// <https://docs.rs/tracing-subscriber/0.2.20/tracing_subscriber/filter/struct.EnvFilter.html>
+    ///
+    /// You can override this setting with the environment variable ARTI_LOG.
+    trace_filter: String,
+
+    /// Whether to log to journald
+    journald: bool,
+}
+
 /// Structure to hold our configuration options, whether from a
 /// configuration file or the command line.
 ///
@@ -138,14 +152,8 @@ pub struct ArtiConfig {
     /// connections.
     socks_port: Option<u16>,
 
-    /// Whether to log to journald
+    /// Logging configuration
-    journald: bool,
+    logging: LoggingConfig,
-
-    /// Filtering directives that determine tracing levels as described at
-    /// <https://docs.rs/tracing-subscriber/0.2.20/tracing_subscriber/filter/struct.EnvFilter.html>
-    ///
-    /// You can override this setting with the environment variable ARTI_LOG.
-    trace_filter: String,
 
     /// Information about the Tor network we want to connect to.
     network: NetworkConfig,
@@ -232,13 +240,13 @@ async fn run<R: Runtime>(
 fn setup_logging(config: &ArtiConfig) {
     let env_filter = match EnvFilter::try_from_env("ARTI_LOG") {
         Ok(f) => f,
-        Err(_e) => EnvFilter::new(config.trace_filter.as_str()),
+        Err(_e) => EnvFilter::new(config.logging.trace_filter.as_str()),
     };
 
     let registry = registry().with(fmt::Layer::default()).with(env_filter);
 
     #[cfg(feature = "journald")]
-    if config.journald {
+    if config.logging.journald {
         if let Ok(journald) = tracing_journald::layer() {
             registry.with(journald).init();
             return;