logging: add ability to log to stderr

control_plane/src/bin/attachment_service.rs

@@ -268,6 +268,7 @@ async fn main() -> anyhow::Result<()> {
     logging::init(
         LogFormat::Plain,
         logging::TracingErrorLayerEnablement::Disabled,
+        logging::Output::Stdout,
     )?;
 
     let args = Cli::parse();

libs/utils/src/logging.rs

@@ -66,9 +66,17 @@ pub enum TracingErrorLayerEnablement {
     EnableWithRustLogFilter,
 }
 
+/// Where the logging should output to.
+#[derive(Clone, Copy)]
+pub enum Output {
+    Stdout,
+    Stderr,
+}
+
 pub fn init(
     log_format: LogFormat,
     tracing_error_layer_enablement: TracingErrorLayerEnablement,
+    output: Output,
 ) -> anyhow::Result<()> {
     // We fall back to printing all spans at info-level or above if
     // the RUST_LOG environment variable is not set.
@@ -85,7 +93,12 @@ pub fn init(
         let log_layer = tracing_subscriber::fmt::layer()
             .with_target(false)
             .with_ansi(false)
-            .with_writer(std::io::stdout);
+            .with_writer(move || -> Box<dyn std::io::Write> {
+                match output {
+                    Output::Stdout => Box::new(std::io::stdout()),
+                    Output::Stderr => Box::new(std::io::stderr()),
+                }
+            });
         let log_layer = match log_format {
             LogFormat::Json => log_layer.json().boxed(),
             LogFormat::Plain => log_layer.boxed(),

pageserver/src/bin/pageserver.rs

@@ -103,7 +103,11 @@ fn main() -> anyhow::Result<()> {
     } else {
         TracingErrorLayerEnablement::Disabled
     };
-    logging::init(conf.log_format, tracing_error_layer_enablement)?;
+    logging::init(
+        conf.log_format,
+        tracing_error_layer_enablement,
+        logging::Output::Stdout,
+    )?;
 
     // mind the order required here: 1. logging, 2. panic_hook, 3. sentry.
     // disarming this hook on pageserver, because we never tear down tracing.

safekeeper/src/bin/safekeeper.rs

@@ -202,6 +202,7 @@ async fn main() -> anyhow::Result<()> {
     logging::init(
         LogFormat::from_config(&args.log_format)?,
         logging::TracingErrorLayerEnablement::Disabled,
+        logging::Output::Stdout,
     )?;
     logging::replace_panic_hook_with_tracing_panic_hook().forget();
     info!("version: {GIT_VERSION}");

storage_broker/src/bin/storage_broker.rs

@@ -434,6 +434,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     logging::init(
         LogFormat::from_config(&args.log_format)?,
         logging::TracingErrorLayerEnablement::Disabled,
+        logging::Output::Stdout,
     )?;
     logging::replace_panic_hook_with_tracing_panic_hook().forget();
     // initialize sentry if SENTRY_DSN is provided