fix: manually pass a meterprovider to host metrics

This suppresses an annoying warning. The host metrics class already gets
the global meter provider in the same way but logs a warning if it has
to. This is a lot of noise in our logs.

packages/opentelemetry/lib/index.js

@@ -8,6 +8,7 @@ const logger = require('@dotcom-reliability-kit/logger');
 
 /**
  * @import { Instances, Options } from '@dotcom-reliability-kit/opentelemetry'
+ * @import { MeterProvider } from '@opentelemetry/sdk-metrics'
  */
 
 /**
@@ -79,7 +80,10 @@ function setupOpenTelemetry({
 
 	// Set up host metrics if we have a metrics endpoint
 	if (metricsOptions?.endpoint) {
-		instances.hostMetrics = new HostMetrics();
+		const meterProvider = /** @type {MeterProvider} */ (
+			opentelemetry.api.metrics.getMeterProvider()
+		);
+		instances.hostMetrics = new HostMetrics({ meterProvider });
 		instances.hostMetrics.start();
 	}
 

packages/opentelemetry/test/unit/lib/index.spec.js

@@ -43,6 +43,7 @@ describe('@dotcom-reliability-kit/opentelemetry', () => {
 		createTracingConfig =
 			require('../../../lib/config/tracing').createTracingConfig;
 		api = require('@opentelemetry/sdk-node').api;
+		api.metrics.getMeterProvider.mockReturnValue('mock-meter-provider');
 		HostMetrics = require('@opentelemetry/host-metrics').HostMetrics;
 		NodeSDK = require('@opentelemetry/sdk-node').NodeSDK;
 		logger = require('@dotcom-reliability-kit/logger');
@@ -185,7 +186,9 @@ describe('@dotcom-reliability-kit/opentelemetry', () => {
 
 		it('instantiates and starts a HostMetrics collector', () => {
 			expect(HostMetrics).toHaveBeenCalledTimes(1);
-			expect(HostMetrics).toHaveBeenCalledWith();
+			expect(HostMetrics).toHaveBeenCalledWith({
+				meterProvider: 'mock-meter-provider'
+			});
 			expect(HostMetrics.prototype.start).toHaveBeenCalledTimes(1);
 		});