Move observability config to separate config section

This renames:

allow_prometheus -> observability.metrics.enable
allow_jaeger -> observability.traces.enable
tracing_flame -> observability.flame.enable
log -> observability.logs.filter
log_colors -> observability.logs.colors
log_format -> observability.logs.format

New config values in these sections will follow.

src/config.rs

@@ -58,23 +58,13 @@ pub(crate) struct Config {
     pub(crate) allow_unstable_room_versions: bool,
     #[serde(default = "default_default_room_version")]
     pub(crate) default_room_version: RoomVersionId,
-    #[serde(default = "false_fn")]
-    pub(crate) allow_jaeger: bool,
-    #[serde(default = "false_fn")]
-    pub(crate) allow_prometheus: bool,
-    #[serde(default = "false_fn")]
-    pub(crate) tracing_flame: bool,
     #[serde(default)]
     pub(crate) proxy: ProxyConfig,
     pub(crate) jwt_secret: Option<String>,
     #[serde(default = "default_trusted_servers")]
     pub(crate) trusted_servers: Vec<OwnedServerName>,
-    #[serde(default = "default_log")]
-    pub(crate) log: EnvFilterClone,
-    #[serde(default = "true_fn")]
-    pub(crate) log_colors: bool,
     #[serde(default)]
-    pub(crate) log_format: LogFormat,
+    pub(crate) observability: ObservabilityConfig,
     #[serde(default)]
     pub(crate) turn: TurnConfig,
 
@@ -184,6 +174,55 @@ pub(crate) struct DatabaseConfig {
     pub(crate) rocksdb_max_open_files: i32,
 }
 
+#[derive(Clone, Debug, Default, Deserialize)]
+#[serde(default)]
+pub(crate) struct MetricsConfig {
+    pub(crate) enable: bool,
+}
+
+#[derive(Clone, Debug, Default, Deserialize)]
+#[serde(default)]
+pub(crate) struct OtelTraceConfig {
+    pub(crate) enable: bool,
+}
+
+#[derive(Clone, Debug, Default, Deserialize)]
+#[serde(default)]
+pub(crate) struct FlameConfig {
+    pub(crate) enable: bool,
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(default)]
+pub(crate) struct LogConfig {
+    pub(crate) filter: EnvFilterClone,
+    pub(crate) colors: bool,
+    pub(crate) format: LogFormat,
+}
+
+impl Default for LogConfig {
+    fn default() -> Self {
+        Self {
+            filter: default_log(),
+            colors: true,
+            format: LogFormat::default(),
+        }
+    }
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub(crate) struct ObservabilityConfig {
+    /// Prometheus metrics
+    pub(crate) metrics: MetricsConfig,
+    /// OpenTelemetry traces
+    pub(crate) traces: OtelTraceConfig,
+    /// Folded inferno stack traces
+    pub(crate) flame: FlameConfig,
+    /// Logging to stdout
+    pub(crate) logs: LogConfig,
+}
+
 fn false_fn() -> bool {
     false
 }

src/main.rs

@@ -442,7 +442,7 @@ fn routes(config: &Config) -> Router {
                 .put(c2s::send_state_event_for_empty_key_route),
         );
 
-    let router = if config.allow_prometheus {
+    let router = if config.observability.metrics.enable {
         router.route(
             "/metrics",
             get(|| async { observability::METRICS.export() }),

src/observability.rs

@@ -87,7 +87,9 @@ pub(crate) enum FoundIn {
 /// Initialize observability
 pub(crate) fn init(config: &Config) -> Result<Guard, error::Observability> {
     let jaeger_layer = config
-        .allow_jaeger
+        .observability
+        .traces
+        .enable
         .then(|| {
             opentelemetry::global::set_text_map_propagator(
                 opentelemetry_jaeger_propagator::Propagator::new(),
@@ -102,36 +104,41 @@ pub(crate) fn init(config: &Config) -> Result<Guard, error::Observability> {
                 .install_batch(opentelemetry_sdk::runtime::Tokio)?;
             let telemetry = tracing_opentelemetry::layer().with_tracer(tracer);
 
-            Ok::<_, error::Observability>(
+            Ok::<_, error::Observability>(telemetry.with_filter(
-                telemetry.with_filter(EnvFilter::from(&config.log)),
+                EnvFilter::from(&config.observability.logs.filter),
-            )
+            ))
         })
         .transpose()?;
 
     let (flame_layer, flame_guard) = config
-        .tracing_flame
+        .observability
+        .flame
+        .enable
         .then(|| {
             let (flame_layer, guard) =
                 FlameLayer::with_file("./tracing.folded")?;
             let flame_layer = flame_layer.with_empty_samples(false);
 
             Ok::<_, error::Observability>((
-                flame_layer.with_filter(EnvFilter::from(&config.log)),
+                flame_layer.with_filter(EnvFilter::from(
+                    &config.observability.logs.filter,
+                )),
                 guard,
             ))
         })
         .transpose()?
         .unzip();
 
-    let fmt_layer =
+    let fmt_layer = tracing_subscriber::fmt::Layer::new()
-        tracing_subscriber::fmt::Layer::new().with_ansi(config.log_colors);
+        .with_ansi(config.observability.logs.colors);
-    let fmt_layer = match config.log_format {
+    let fmt_layer = match config.observability.logs.format {
         LogFormat::Pretty => fmt_layer.pretty().boxed(),
         LogFormat::Full => fmt_layer.boxed(),
         LogFormat::Compact => fmt_layer.compact().boxed(),
         LogFormat::Json => fmt_layer.json().boxed(),
     };
-    let fmt_layer = fmt_layer.with_filter(EnvFilter::from(&config.log));
+    let fmt_layer = fmt_layer
+        .with_filter(EnvFilter::from(&config.observability.logs.filter));
 
     let subscriber = Registry::default()
         .with(jaeger_layer)