From b2b20072ae1bbf8879afe58006daca7e3d65f32c Mon Sep 17 00:00:00 2001
From: Chris Eager <chris@signal.org>
Date: Wed, 16 Feb 2022 15:41:02 -0800
Subject: [PATCH] Add `MicrometerRegistryManager`

---
 .../textsecuregcm/WhisperServerService.java   |  3 ++
 .../metrics/MicrometerRegistryManager.java    | 29 +++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 service/src/main/java/org/whispersystems/textsecuregcm/metrics/MicrometerRegistryManager.java

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
index ef721fe7a..b7e06c777 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
@@ -134,6 +134,7 @@ import org.whispersystems.textsecuregcm.metrics.GarbageCollectionGauges;
 import org.whispersystems.textsecuregcm.metrics.MaxFileDescriptorGauge;
 import org.whispersystems.textsecuregcm.metrics.MetricsApplicationEventListener;
 import org.whispersystems.textsecuregcm.metrics.MetricsRequestEventListener;
+import org.whispersystems.textsecuregcm.metrics.MicrometerRegistryManager;
 import org.whispersystems.textsecuregcm.metrics.NetworkReceivedGauge;
 import org.whispersystems.textsecuregcm.metrics.NetworkSentGauge;
 import org.whispersystems.textsecuregcm.metrics.OperatingSystemMemoryGauge;
@@ -296,6 +297,8 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
       Metrics.addRegistry(datadogMeterRegistry);
     }
 
+    environment.lifecycle().manage(new MicrometerRegistryManager(Metrics.globalRegistry));
+
     environment.getObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
     environment.getObjectMapper().setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
     environment.getObjectMapper().setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MicrometerRegistryManager.java b/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MicrometerRegistryManager.java
new file mode 100644
index 000000000..4fc55043c
--- /dev/null
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/metrics/MicrometerRegistryManager.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2022 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.metrics;
+
+import io.dropwizard.lifecycle.Managed;
+import io.micrometer.core.instrument.MeterRegistry;
+
+public class MicrometerRegistryManager implements Managed {
+
+  private final MeterRegistry meterRegistry;
+
+  public MicrometerRegistryManager(final MeterRegistry meterRegistry) {
+    this.meterRegistry = meterRegistry;
+  }
+
+  @Override
+  public void start() throws Exception {
+
+  }
+
+  @Override
+  public void stop() throws Exception {
+    // closing the registry publishes one final set of metrics
+    meterRegistry.close();
+  }
+}