From 9ab2f05fca24c0e4daad8c5391938823432ad531 Mon Sep 17 00:00:00 2001
From: Carlos Crespo <carloshenrique.leonelcrespo@elastic.co>
Date: Wed, 13 Jul 2022 16:43:47 +0200
Subject: [PATCH] Enable otlp logging and compatibility with env vars

---
 package.json                                  |  1 +
 .../plugins/monitoring_collection/README.md   |  9 +++++++++
 .../monitoring_collection/server/config.ts    |  1 +
 .../monitoring_collection/server/plugin.ts    | 20 ++++++++++++++++---
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index e9687d0f3e412..99b9a6aa55da6 100644
--- a/package.json
+++ b/package.json
@@ -275,6 +275,7 @@
     "@mapbox/mapbox-gl-draw": "1.3.0",
     "@mapbox/mapbox-gl-rtl-text": "0.2.3",
     "@mapbox/vector-tile": "1.3.1",
+    "@opentelemetry/api": "^1.1.0",
     "@opentelemetry/api-metrics": "^0.30.0",
     "@opentelemetry/exporter-metrics-otlp-grpc": "^0.30.0",
     "@opentelemetry/exporter-prometheus": "^0.30.0",
diff --git a/x-pack/plugins/monitoring_collection/README.md b/x-pack/plugins/monitoring_collection/README.md
index 13b8396f01b3e..b5e8a38d16ad6 100644
--- a/x-pack/plugins/monitoring_collection/README.md
+++ b/x-pack/plugins/monitoring_collection/README.md
@@ -49,6 +49,15 @@ monitoring_collection.opentelemetry.metrics:
       Authorization: "Bearer SECRET_TOKEN"
 ```
 
+Alternatively, OTLP Exporter can be configured using environment variables `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT`, `OTEL_EXPORTER_OTLP_METRICS_HEADERS`. [See OTLP Exporter docs](https://opentelemetry.io/docs/reference/specification/protocol/exporter/) for details.
+
+It's possible to configure logging for the OTLP integration. If not informed, the default will be `info`
+
+```yml
+monitoring_collection.opentelemetry.metrics:
+  logLevel: warn | info | debug | warn | none | verbose | all
+```
+
 For connection-level debug information you can set these variables:
 
 ```bash
diff --git a/x-pack/plugins/monitoring_collection/server/config.ts b/x-pack/plugins/monitoring_collection/server/config.ts
index 6efe92986ddd5..5eda950ebe7f1 100644
--- a/x-pack/plugins/monitoring_collection/server/config.ts
+++ b/x-pack/plugins/monitoring_collection/server/config.ts
@@ -15,6 +15,7 @@ export const configSchema = schema.object({
         url: schema.maybe(schema.string()),
         headers: schema.maybe(schema.recordOf(schema.string(), schema.string())),
         exportIntervalMillis: schema.number({ defaultValue: 10000 }),
+        logLevel: schema.string({ defaultValue: 'info' }),
       }),
       prometheus: schema.object({
         enabled: schema.boolean({ defaultValue: false }),
diff --git a/x-pack/plugins/monitoring_collection/server/plugin.ts b/x-pack/plugins/monitoring_collection/server/plugin.ts
index e0a0fc76a23ac..818dd81a9c303 100644
--- a/x-pack/plugins/monitoring_collection/server/plugin.ts
+++ b/x-pack/plugins/monitoring_collection/server/plugin.ts
@@ -18,6 +18,7 @@ import { metrics } from '@opentelemetry/api-metrics';
 import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
 import { MeterProvider, PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics-base';
 import { Resource } from '@opentelemetry/resources';
+import { diag, DiagLogger, DiagLogLevel } from '@opentelemetry/api';
 import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
 import * as grpc from '@grpc/grpc-js';
 import { PrometheusExporter } from './lib/prometheus_exporter';
@@ -41,6 +42,7 @@ export class MonitoringCollectionPlugin implements Plugin<MonitoringCollectionSe
   private readonly initializerContext: PluginInitializerContext;
   private readonly logger: Logger;
   private readonly config: MonitoringCollectionConfig;
+  private readonly otlpLogger: DiagLogger;
 
   private metrics: Record<string, Metric<any>> = {};
 
@@ -50,6 +52,14 @@ export class MonitoringCollectionPlugin implements Plugin<MonitoringCollectionSe
     this.initializerContext = initializerContext;
     this.logger = initializerContext.logger.get();
     this.config = initializerContext.config.get();
+
+    this.otlpLogger = {
+      debug: (message) => this.logger.debug(message),
+      error: (message) => this.logger.error(message),
+      info: (message) => this.logger.info(message),
+      warn: (message) => this.logger.warn(message),
+      verbose: (message) => this.logger.trace(message),
+    };
   }
 
   async getMetric(type: string) {
@@ -127,11 +137,12 @@ export class MonitoringCollectionPlugin implements Plugin<MonitoringCollectionSe
     metrics.setGlobalMeterProvider(meterProvider);
 
     const otlpConfig = this.config.opentelemetry?.metrics.otlp;
-    if (otlpConfig?.url) {
+    const url = otlpConfig?.url ?? process.env.OTEL_EXPORTER_OTLP_METRICS_ENDPOINT;
+    if (url) {
       // Add OTLP exporter
-      const url = otlpConfig.url;
-
       // Set Authorization headers
+      // OTLPMetricExporter internally will look at OTEL_EXPORTER_OTLP_METRICS_HEADERS env variable
+      // if `headers` are not present in the kibana config file
       const metadata = new grpc.Metadata();
       if (otlpConfig.headers) {
         for (const [key, value] of Object.entries(otlpConfig.headers)) {
@@ -139,6 +150,9 @@ export class MonitoringCollectionPlugin implements Plugin<MonitoringCollectionSe
         }
       }
 
+      const otlpLogLevel = otlpConfig.logLevel.toUpperCase() as keyof typeof DiagLogLevel;
+      diag.setLogger(this.otlpLogger, DiagLogLevel[otlpLogLevel]);
+
       this.logger.debug(`Registering OpenTelemetry metrics exporter to ${url}`);
       meterProvider.addMetricReader(
         new PeriodicExportingMetricReader({