Initialize metrics with tokio-console (#6448)

Co-authored-by: Luca Cominardi <luca.cominardi@proton.me>

Author: shuheiktgw

quickwit/quickwit-cli/src/main.rs

@@ -93,9 +93,11 @@ fn init_telemetry(
     #[cfg(feature = "tokio-console")]
     {
         if quickwit_common::get_bool_from_env(QW_ENABLE_TOKIO_CONSOLE_ENV_KEY, false) {
+            let telemetry_handle =
+                quickwit_telemetry_exporters::init_meter_provider_only(service_version)?;
             console_subscriber::init();
             return Ok((
-                quickwit_telemetry_exporters::TelemetryHandle::default(),
+                telemetry_handle,
                 quickwit_telemetry_exporters::do_nothing_env_filter_reload_fn(),
             ));
         }

quickwit/quickwit-telemetry-exporters/src/lib.rs

@@ -41,7 +41,6 @@ pub fn do_nothing_env_filter_reload_fn() -> EnvFilterReloadFn {
     Arc::new(|_| Ok(()))
 }
 
-#[derive(Default)]
 pub struct TelemetryHandle {
     tracer_provider: Option<SdkTracerProvider>,
     logger_provider: Option<SdkLoggerProvider>,
@@ -170,3 +169,17 @@ pub fn init_telemetry(
 
     Ok(telemetry_handle)
 }
+
+/// Initializes only metrics providers for the process.
+///
+/// This is useful when another component owns the tracing subscriber setup but
+/// Quickwit still needs to install its metrics recorder.
+pub fn init_meter_provider_only(service_version: &str) -> anyhow::Result<TelemetryHandle> {
+    let otlp_config = otlp::OtlpExporterConfig::load_from_env();
+    let meter_provider = metrics::init_metrics_provider(service_version, &otlp_config)?;
+    Ok(TelemetryHandle {
+        tracer_provider: None,
+        logger_provider: None,
+        meter_provider,
+    })
+}