feat!: adapt monitoring code to new implementation

- record:
  * received events
  * deleted events
  * reconciliation attempts with retry information
  * reconciliation successes
  * reconciliation failure with exception information
- move metrics-related code to monitoring package
- cleaned-up obsolete/deprecated code

Author: metacosm

micrometer-support/src/main/java/io/javaoperatorsdk/operator/micrometer/MicrometerMetrics.java

@@ -0,0 +1,98 @@
+package io.javaoperatorsdk.operator.monitoring.micrometer;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import io.javaoperatorsdk.operator.api.RetryInfo;
+import io.javaoperatorsdk.operator.api.monitoring.Metrics;
+import io.javaoperatorsdk.operator.processing.event.CustomResourceID;
+import io.javaoperatorsdk.operator.processing.event.Event;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Timer;
+
+public class MicrometerMetrics implements Metrics {
+
+  private static final String PREFIX = "operator.sdk.";
+  private static final String RECONCILIATIONS = "reconciliations.";
+  private final MeterRegistry registry;
+
+  public MicrometerMetrics(MeterRegistry registry) {
+    this.registry = registry;
+  }
+
+  public <T> T timeControllerExecution(ControllerExecution<T> execution) {
+    final var name = execution.controllerName();
+    final var execName = PREFIX + "controllers.execution." + execution.name();
+    final var timer =
+        Timer.builder(execName)
+            .tags("controller", name)
+            .publishPercentiles(0.3, 0.5, 0.95)
+            .publishPercentileHistogram()
+            .register(registry);
+    try {
+      final var result = timer.record(execution::execute);
+      final var successType = execution.successTypeName(result);
+      registry
+          .counter(execName + ".success", "controller", name, "type", successType)
+          .increment();
+      return result;
+    } catch (Exception e) {
+      final var exception = e.getClass().getSimpleName();
+      registry
+          .counter(execName + ".failure", "controller", name, "exception", exception)
+          .increment();
+      throw e;
+    }
+  }
+
+  public void receivedEvent(Event event) {
+    incrementCounter(event.getRelatedCustomResourceID(), "events.received", "event",
+        event.getClass().getSimpleName());
+  }
+
+  @Override
+  public void cleanupDoneFor(CustomResourceID customResourceUid) {
+    incrementCounter(customResourceUid, "events.delete");
+  }
+
+  public void reconcileCustomResource(CustomResourceID customResourceID,
+      RetryInfo retryInfo) {
+    incrementCounter(customResourceID, RECONCILIATIONS + "started",
+        RECONCILIATIONS + "retries.number", "" + retryInfo.getAttemptCount(),
+        RECONCILIATIONS + "retries.last", "" + retryInfo.isLastAttempt());
+  }
+
+  @Override
+  public void finishedReconciliation(CustomResourceID customResourceID) {
+    incrementCounter(customResourceID, RECONCILIATIONS + "success");
+  }
+
+  public void failedReconciliation(CustomResourceID customResourceID, RuntimeException exception) {
+    var cause = exception.getCause();
+    if (cause == null) {
+      cause = exception;
+    } else if (cause instanceof RuntimeException) {
+      cause = cause.getCause() != null ? cause.getCause() : cause;
+    }
+    incrementCounter(customResourceID, RECONCILIATIONS + "failed", "exception",
+        cause.getClass().getSimpleName());
+  }
+
+  public <T extends Map<?, ?>> T monitorSizeOf(T map, String name) {
+    return registry.gaugeMapSize(PREFIX + name + ".size", Collections.emptyList(), map);
+  }
+
+  private void incrementCounter(CustomResourceID id, String counterName, String... additionalTags) {
+    var tags = List.of(
+        "name", id.getName(),
+        "name", id.getName(), "namespace", id.getNamespace().orElse(""),
+        "scope", id.getNamespace().isPresent() ? "namespace" : "cluster");
+    if (additionalTags != null && additionalTags.length > 0) {
+      tags = new LinkedList<>(tags);
+      tags.addAll(List.of(additionalTags));
+    }
+    registry.counter(PREFIX + counterName, tags.toArray(new String[0])).increment();
+  }
+}

micrometer-support/src/main/java/io/javaoperatorsdk/operator/monitoring/micrometer/MicrometerMetrics.java

@@ -6,8 +6,8 @@
 
 import io.fabric8.kubernetes.client.Config;
 import io.fabric8.kubernetes.client.CustomResource;
-import io.javaoperatorsdk.operator.Metrics;
 import io.javaoperatorsdk.operator.api.ResourceController;
+import io.javaoperatorsdk.operator.api.monitoring.Metrics;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/EventListUtils.java

@@ -4,8 +4,8 @@
 
 import io.fabric8.kubernetes.client.Config;
 import io.fabric8.kubernetes.client.CustomResource;
-import io.javaoperatorsdk.operator.Metrics;
 import io.javaoperatorsdk.operator.api.ResourceController;
+import io.javaoperatorsdk.operator.api.monitoring.Metrics;
 
 public class ConfigurationServiceOverrider {
   private final ConfigurationService original;

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Metrics.java

@@ -0,0 +1,42 @@
+package io.javaoperatorsdk.operator.api.monitoring;
+
+import java.util.Map;
+
+import io.javaoperatorsdk.operator.api.RetryInfo;
+import io.javaoperatorsdk.operator.processing.event.CustomResourceID;
+import io.javaoperatorsdk.operator.processing.event.Event;
+
+public interface Metrics {
+  Metrics NOOP = new Metrics() {};
+
+  default void receivedEvent(Event event) {}
+
+  default void reconcileCustomResource(CustomResourceID customResourceID,
+      RetryInfo retryInfo) {}
+
+  default void failedReconciliation(CustomResourceID customResourceID,
+      RuntimeException exception) {}
+
+  default void cleanupDoneFor(CustomResourceID customResourceUid) {};
+
+  default void finishedReconciliation(CustomResourceID resourceID) {};
+
+
+  interface ControllerExecution<T> {
+    String name();
+
+    String controllerName();
+
+    String successTypeName(T result);
+
+    T execute();
+  }
+
+  default <T> T timeControllerExecution(ControllerExecution<T> execution) {
+    return execution.execute();
+  }
+
+  default <T extends Map<?, ?>> T monitorSizeOf(T map, String name) {
+    return map;
+  }
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java

@@ -11,11 +11,11 @@
 import io.fabric8.kubernetes.client.dsl.MixedOperation;
 import io.fabric8.kubernetes.client.dsl.Resource;
 import io.javaoperatorsdk.operator.CustomResourceUtils;
-import io.javaoperatorsdk.operator.Metrics.ControllerExecution;
 import io.javaoperatorsdk.operator.MissingCRDException;
 import io.javaoperatorsdk.operator.OperatorException;
 import io.javaoperatorsdk.operator.api.*;
 import io.javaoperatorsdk.operator.api.config.ControllerConfiguration;
+import io.javaoperatorsdk.operator.api.monitoring.Metrics.ControllerExecution;
 import io.javaoperatorsdk.operator.processing.event.DefaultEventSourceManager;
 import io.javaoperatorsdk.operator.processing.event.EventSourceManager;