feat: predefined kind telemetry-to-otlp (#247)

closes #243

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ### Added
 
+- Predefined kind `telemetry-to-otlp` that creates exporters based on OTLP exporter configuration via environment variables
 - Experimental!: Propagate W3C trace context to SAP HANA via session context `SAP_PASSPORT`
   - Enable via environment variable `SAP_PASSPORT`
 - If `@opentelemetry/instrumentation-runtime-node` is in the project's dependencies but not in `cds.env.requires.telemetry.instrumentations`, it is registered automatically

README.md

@@ -26,6 +26,7 @@ Documentation can be found at [cap.cloud.sap](https://cap.cloud.sap/docs) and [o
   - [`telemetry-to-dynatrace`](#telemetry-to-dynatrace)
   - [`telemetry-to-cloud-logging`](#telemetry-to-cloud-logging)
   - [`telemetry-to-jaeger`](#telemetry-to-jaeger)
+  - [`telemetry-to-otlp`](#telemetry-to-otlp)
 - [Detailed Configuration Options](#detailed-configuration-options)
   - [Configuration Pass Through](#configuration-pass-through)
   - [Instrumentations](#instrumentations)
@@ -262,6 +263,19 @@ Run Jaeger locally via [docker](https://www.docker.com):
     - With this, no custom credentials are needed
 - Open `localhost:16686` to see the traces
 
+### `telemetry-to-otlp`
+
+Exports traces and metrics to an OTLP/gRPC or OTLP/HTTP endpoint based on [environment variables](https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter).
+
+Use via `cds.requires.telemetry.kind = 'to-otlp'`.
+
+Required additional dependencies (`* = grpc|proto|http`):
+- `@grpc/grpc-js` (in case of OTLP/gRPC)
+- `@opentelemetry/exporter-trace-otlp-*`
+- `@opentelemetry/exporter-metrics-otlp-*`
+
+Please note that `@cap-js/telemetry` does not validate the configuration via environment variables!
+
 
 
 ## Detailed Configuration Options

lib/metrics/index.js

@@ -2,6 +2,7 @@ const cds = require('@sap/cds')
 const LOG = cds.log('telemetry')
 
 const { metrics } = require('@opentelemetry/api')
+const { getEnv, getEnvWithoutDefaults } = require('@opentelemetry/core')
 const { Resource } = require('@opentelemetry/resources')
 const {
   AggregationTemporality,
@@ -13,21 +14,39 @@ const {
 
 const { getDynatraceMetadata, getCredsForDTAsUPS, getCredsForCLSAsUPS, augmentCLCreds, _require } = require('../utils')
 
+const _protocol2module = {
+  grpc: '@opentelemetry/exporter-metrics-otlp-grpc',
+  'http/protobuf': '@opentelemetry/exporter-metrics-otlp-proto',
+  'http/json': '@opentelemetry/exporter-metrics-otlp-http'
+}
+
 function _getExporter() {
   let {
     kind,
     metrics: { exporter: metricsExporter },
     credentials
   } = cds.env.requires.telemetry
 
+  // for kind telemetry-to-otlp based on env vars
+  if (metricsExporter === 'env') {
+    const otlp_env = getEnvWithoutDefaults()
+    const dflt_env = getEnv()
+    const protocol =
+      otlp_env.OTEL_EXPORTER_OTLP_METRICS_PROTOCOL ??
+      otlp_env.OTEL_EXPORTER_OTLP_PROTOCOL ??
+      dflt_env.OTEL_EXPORTER_OTLP_METRICS_PROTOCOL ??
+      dflt_env.OTEL_EXPORTER_OTLP_PROTOCOL
+    metricsExporter = { module: _protocol2module[protocol], class: 'OTLPMetricExporter' }
+  }
+
   // use _require for better error message
   const metricsExporterModule =
     metricsExporter.module === '@cap-js/telemetry' ? require('../exporter') : _require(metricsExporter.module)
   if (!metricsExporterModule[metricsExporter.class])
     throw new Error(`Unknown metrics exporter "${metricsExporter.class}" in module "${metricsExporter.module}"`)
   const metricsConfig = { ...(metricsExporter.config || {}) }
 
-  if (kind.match(/dynatrace/)) {
+  if (kind.match(/to-dynatrace$/)) {
     if (!credentials) credentials = getCredsForDTAsUPS()
     if (!credentials) throw new Error('No Dynatrace credentials found.')
     metricsConfig.url ??= `${credentials.apiurl}/v2/otlp/v1/metrics`
@@ -41,7 +60,7 @@ function _getExporter() {
     metricsConfig.headers.authorization ??= `Api-Token ${token}`
   }
 
-  if (kind.match(/cloud-logging/)) {
+  if (kind.match(/to-cloud-logging$/)) {
     if (!credentials) credentials = getCredsForCLSAsUPS()
     if (!credentials) throw new Error('No SAP Cloud Logging credentials found.')
     augmentCLCreds(credentials)

lib/tracing/index.js

@@ -2,6 +2,7 @@ const cds = require('@sap/cds')
 const LOG = cds.log('telemetry')
 
 const { trace } = require('@opentelemetry/api')
+const { getEnv, getEnvWithoutDefaults } = require('@opentelemetry/core')
 const { Resource } = require('@opentelemetry/resources')
 const { BatchSpanProcessor, SimpleSpanProcessor, SamplingDecision } = require('@opentelemetry/sdk-trace-base')
 const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node')
@@ -69,21 +70,39 @@ function _getPropagator() {
   return new core.CompositePropagator({ propagators })
 }
 
+const _protocol2module = {
+  grpc: '@opentelemetry/exporter-trace-otlp-grpc',
+  'http/protobuf': '@opentelemetry/exporter-trace-otlp-proto',
+  'http/json': '@opentelemetry/exporter-trace-otlp-http'
+}
+
 function _getExporter() {
   let {
     kind,
     tracing: { exporter: tracingExporter },
     credentials
   } = cds.env.requires.telemetry
 
+  // for kind telemetry-to-otlp based on env vars
+  if (tracingExporter === 'env') {
+    const otlp_env = getEnvWithoutDefaults()
+    const dflt_env = getEnv()
+    const protocol =
+      otlp_env.OTEL_EXPORTER_OTLP_TRACES_PROTOCOL ??
+      otlp_env.OTEL_EXPORTER_OTLP_PROTOCOL ??
+      dflt_env.OTEL_EXPORTER_OTLP_TRACES_PROTOCOL ??
+      dflt_env.OTEL_EXPORTER_OTLP_PROTOCOL
+    tracingExporter = { module: _protocol2module[protocol], class: 'OTLPTraceExporter' }
+  }
+
   // use _require for better error message
   const tracingExporterModule =
     tracingExporter.module === '@cap-js/telemetry' ? require('../exporter') : _require(tracingExporter.module)
   if (!tracingExporterModule[tracingExporter.class])
     throw new Error(`Unknown tracing exporter "${tracingExporter.class}" in module "${tracingExporter.module}"`)
   const tracingConfig = { ...(tracingExporter.config || {}) }
 
-  if (kind.match(/dynatrace/)) {
+  if (kind.match(/to-dynatrace$/)) {
     if (!credentials) credentials = getCredsForDTAsUPS()
     if (!credentials) throw new Error('No Dynatrace credentials found')
     tracingConfig.url ??= `${credentials.apiurl}/v2/otlp/v1/traces`
@@ -96,7 +115,7 @@ function _getExporter() {
     tracingConfig.headers.authorization ??= `Api-Token ${token}`
   }
 
-  if (kind.match(/cloud-logging/)) {
+  if (kind.match(/to-cloud-logging$/)) {
     if (!credentials) credentials = getCredsForCLSAsUPS()
     if (!credentials) throw new Error('No SAP Cloud Logging credentials found')
     augmentCLCreds(credentials)
@@ -127,7 +146,7 @@ module.exports = resource => {
   }
   const via_one_agent =
     process.env.DT_NODE_PRELOAD_OPTIONS &&
-    cds.env.requires.telemetry.kind.match(/dynatrace/) &&
+    cds.env.requires.telemetry.kind.match(/to-dynatrace$/) &&
     !hasDependency('@opentelemetry/exporter-trace-otlp-proto')
   if (via_one_agent) {
     // if Dynatrace OneAgent is present, no exporter is needed

package.json

@@ -146,6 +146,14 @@
               "class": "OTLPTraceExporter"
             }
           }
+        },
+        "telemetry-to-otlp": {
+          "tracing": {
+            "exporter": "env"
+          },
+          "metrics": {
+            "exporter": "env"
+          }
         }
       }
     }