feat: Add graceful shutdown (#788)

* feat: Add graceful shutdown

* chore: Add changelog entry

Author: Techassi

CHANGELOG.md

@@ -15,9 +15,11 @@ All notable changes to this project will be documented in this file.
 
 ### Changed
 
+- Gracefully shutdown all concurrent tasks by forwarding the SIGTERM signal ([#788]).
 - Bump testing-tools to `0.3.0-stackable0.0.0-dev` ([#780]).
 
 [#780]: https://github.com/stackabletech/druid-operator/pull/780
+[#788]: https://github.com/stackabletech/druid-operator/pull/788
 
 ## [25.11.0] - 2025-11-07
 

Cargo.lock

@@ -11,7 +11,7 @@ repository = "https://github.com/stackabletech/druid-operator"
 
 [workspace.dependencies]
 product-config = { git = "https://github.com/stackabletech/product-config.git", tag = "0.8.0" }
-stackable-operator = { git = "https://github.com/stackabletech/operator-rs.git", tag = "stackable-operator-0.104.0", features = ["telemetry", "versioned"] }
+stackable-operator = { git = "https://github.com/stackabletech/operator-rs.git", tag = "stackable-operator-0.105.0", features = ["telemetry", "versioned"] }
 
 anyhow = "1.0"
 built = { version = "0.8", features = ["chrono", "git2"] }

Cargo.nix

@@ -28,6 +28,7 @@ use stackable_operator::{
     logging::controller::report_controller_reconciled,
     shared::yaml::SerializeOptions,
     telemetry::Tracing,
+    utils::signal::SignalWatcher,
 };
 
 use crate::crd::{DruidCluster, DruidClusterVersion, OPERATOR_NAME, v1alpha1};
@@ -85,9 +86,13 @@ async fn main() -> anyhow::Result<()> {
                 description = built_info::PKG_DESCRIPTION
             );
 
+            // Watches for the SIGTERM signal and sends a signal to all receivers, which gracefully
+            // shuts down all concurrent tasks below (EoS checker, controller).
+            let sigterm_watcher = SignalWatcher::sigterm()?;
+
             let eos_checker =
                 EndOfSupportChecker::new(built_info::BUILT_TIME_UTC, maintenance.end_of_support)?
-                    .run()
+                    .run(sigterm_watcher.handle())
                     .map(anyhow::Ok);
 
             let product_config = product_config.load(&[
@@ -126,7 +131,6 @@ async fn main() -> anyhow::Result<()> {
                     watch_namespace.get_api::<ConfigMap>(&client),
                     watcher::Config::default(),
                 )
-                .shutdown_on_signal()
                 .watches(
                     watch_namespace.get_api::<DeserializeGuard<ConfigMap>>(&client),
                     watcher::Config::default(),
@@ -138,6 +142,7 @@ async fn main() -> anyhow::Result<()> {
                             .map(|druid| ObjectRef::from_obj(&*druid))
                     },
                 )
+                .graceful_shutdown_on(sigterm_watcher.handle())
                 .run(
                     druid_controller::reconcile_druid,
                     druid_controller::error_policy,