feat: add minimal health check

core/deployment/src/main/java/io/quarkiverse/operatorsdk/deployment/OperatorSDKProcessor.java

@@ -34,6 +34,7 @@
 import io.quarkiverse.operatorsdk.runtime.ConfigurationServiceRecorder;
 import io.quarkiverse.operatorsdk.runtime.KubernetesClientSerializationCustomizer;
 import io.quarkiverse.operatorsdk.runtime.NoOpMetricsProvider;
+import io.quarkiverse.operatorsdk.runtime.OperatorHealthCheck;
 import io.quarkiverse.operatorsdk.runtime.OperatorProducer;
 import io.quarkiverse.operatorsdk.runtime.QuarkusConfigurationService;
 import io.quarkiverse.operatorsdk.runtime.ResourceInfo;
@@ -99,6 +100,9 @@ void setup(BuildProducer<IndexDependencyBuildItem> indexDependency,
         } else {
             additionalBeans.produce(AdditionalBeanBuildItem.unremovableOf(NoOpMetricsProvider.class));
         }
+
+        // register health check
+        additionalBeans.produce(AdditionalBeanBuildItem.unremovableOf(OperatorHealthCheck.class));
     }
 
     @BuildStep

core/runtime/src/main/java/io/quarkiverse/operatorsdk/runtime/OperatorHealthCheck.java

@@ -0,0 +1,47 @@
+package io.quarkiverse.operatorsdk.runtime;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.inject.Inject;
+
+import org.eclipse.microprofile.health.HealthCheck;
+import org.eclipse.microprofile.health.HealthCheckResponse;
+import org.eclipse.microprofile.health.Readiness;
+
+import io.javaoperatorsdk.operator.Operator;
+
+@Readiness
+@ApplicationScoped
+public class OperatorHealthCheck implements HealthCheck {
+
+    public static final String HEALTH_CHECK_NAME = "Quarkus Operator SDK health check";
+    public static final String OK = "OK";
+    @Inject
+    Operator operator;
+
+    @Override
+    public HealthCheckResponse call() {
+        final var runtimeInfo = operator.getRuntimeInfo();
+        if (runtimeInfo.isStarted()) {
+            final var response = HealthCheckResponse.named(HEALTH_CHECK_NAME);
+            final boolean[] healthy = { true };
+            runtimeInfo.getRegisteredControllers().forEach(rc -> {
+                final var name = rc.getConfiguration().getName();
+                final var unhealthy = rc.getControllerHealthInfo().unhealthyEventSources();
+                if (unhealthy.isEmpty()) {
+                    response.withData(name, OK);
+                } else {
+                    healthy[0] = false;
+                    response
+                            .withData(name, "unhealthy: " + String.join(", ", unhealthy.keySet()));
+                }
+            });
+            if (healthy[0]) {
+                response.up();
+            } else {
+                response.down();
+            }
+            return response.build();
+        }
+        return HealthCheckResponse.down(HEALTH_CHECK_NAME);
+    }
+}