custom processor

lib/logging/index.js

@@ -34,22 +34,40 @@ function _getExporter() {
   const loggingExporterModule = _require(loggingExporter.module)
   if (!loggingExporterModule[loggingExporter.class])
     throw new Error(`Unknown logs exporter "${loggingExporter.class}" in module "${loggingExporter.module}"`)
-  const loggingConfig = { ...(loggingExporter.config || {}) }
+  const config = { ...(loggingExporter.config || {}) }
 
   if (kind.match(/to-cloud-logging$/)) {
     if (!credentials) credentials = getCredsForCLSAsUPS()
     if (!credentials) throw new Error('No SAP Cloud Logging credentials found.')
     augmentCLCreds(credentials)
-    loggingConfig.url ??= credentials.url
-    loggingConfig.credentials ??= credentials.credentials
+    config.url ??= credentials.url
+    config.credentials ??= credentials.credentials
   }
 
-  const exporter = new loggingExporterModule[loggingExporter.class](loggingConfig)
+  const exporter = new loggingExporterModule[loggingExporter.class](config)
   LOG._debug && LOG.debug('Using logs exporter:', exporter)
 
   return exporter
 }
 
+function _getCustomProcessor(exporter) {
+  let {
+    logging: { processor: loggingProcessor }
+  } = cds.env.requires.telemetry
+
+  if (!loggingProcessor) return
+
+  // use _require for better error message
+  const loggingProcessorModule = _require(loggingProcessor.module)
+  if (!loggingProcessorModule[loggingProcessor.class])
+    throw new Error(`Unknown logs processor "${loggingProcessor.class}" in module "${loggingProcessor.module}"`)
+
+  const processor = new loggingProcessorModule[loggingProcessor.class](exporter)
+  LOG._debug && LOG.debug('Using logs processor:', processor)
+
+  return processor
+}
+
 module.exports = resource => {
   if (!cds.env.requires.telemetry.logging?.exporter) return
 
@@ -66,10 +84,12 @@ module.exports = resource => {
   }
 
   const exporter = _getExporter()
+
   const logProcessor =
-    process.env.NODE_ENV === 'production'
+    _getCustomProcessor(exporter) ||
+    (process.env.NODE_ENV === 'production'
       ? new BatchLogRecordProcessor(exporter)
-      : new SimpleLogRecordProcessor(exporter)
+      : new SimpleLogRecordProcessor(exporter))
   loggerProvider.addLogRecordProcessor(logProcessor)
 
   const loggers = {}

lib/metrics/index.js

@@ -44,34 +44,34 @@ function _getExporter() {
     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 || {}) }
+  const config = { ...(metricsExporter.config || {}) }
 
   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`
-    metricsConfig.headers ??= {}
+    config.url ??= `${credentials.apiurl}/v2/otlp/v1/metrics`
+    config.headers ??= {}
     // credentials.rest_apitoken?.token is deprecated and only supported for compatibility reasons
     const { token_name } = cds.env.requires.telemetry
     // metrics_apitoken for compatibility with previous releases
     const token = credentials[token_name] || credentials.metrics_apitoken || credentials.rest_apitoken?.token
     if (!token)
       throw new Error(`Neither "${token_name}" nor deprecated "rest_apitoken.token" found in Dynatrace credentials`)
-    metricsConfig.headers.authorization ??= `Api-Token ${token}`
+    config.headers.authorization ??= `Api-Token ${token}`
   }
 
   if (kind.match(/to-cloud-logging$/)) {
     if (!credentials) credentials = getCredsForCLSAsUPS()
     if (!credentials) throw new Error('No SAP Cloud Logging credentials found.')
     augmentCLCreds(credentials)
-    metricsConfig.url ??= credentials.url
-    metricsConfig.credentials ??= credentials.credentials
+    config.url ??= credentials.url
+    config.credentials ??= credentials.credentials
   }
 
   // default to DELTA
-  metricsConfig.temporalityPreference ??= AggregationTemporality.DELTA
+  config.temporalityPreference ??= AggregationTemporality.DELTA
 
-  const exporter = new metricsExporterModule[metricsExporter.class](metricsConfig)
+  const exporter = new metricsExporterModule[metricsExporter.class](config)
   LOG._debug && LOG.debug('Using metrics exporter:', exporter)
 
   return exporter

lib/tracing/index.js

@@ -100,30 +100,30 @@ function _getExporter() {
     tracingExporter.module === '@cap-js/telemetry' ? require('../exporter') : _require(tracingExporter.module)
   if (!tracingExporterModule[tracingExporter.class])
     throw new Error(`Unknown trace exporter "${tracingExporter.class}" in module "${tracingExporter.module}"`)
-  const tracingConfig = { ...(tracingExporter.config || {}) }
+  const config = { ...(tracingExporter.config || {}) }
 
   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`
-    tracingConfig.headers ??= {}
+    config.url ??= `${credentials.apiurl}/v2/otlp/v1/traces`
+    config.headers ??= {}
     // credentials.rest_apitoken?.token is deprecated and only supported for compatibility reasons
     const { token_name } = cds.env.requires.telemetry
     const token = credentials[token_name] || credentials.rest_apitoken?.token
     if (!token)
       throw new Error(`Neither "${token_name}" nor deprecated "rest_apitoken.token" found in Dynatrace credentials`)
-    tracingConfig.headers.authorization ??= `Api-Token ${token}`
+    config.headers.authorization ??= `Api-Token ${token}`
   }
 
   if (kind.match(/to-cloud-logging$/)) {
     if (!credentials) credentials = getCredsForCLSAsUPS()
     if (!credentials) throw new Error('No SAP Cloud Logging credentials found')
     augmentCLCreds(credentials)
-    tracingConfig.url ??= credentials.url
-    tracingConfig.credentials ??= credentials.credentials
+    config.url ??= credentials.url
+    config.credentials ??= credentials.credentials
   }
 
-  const exporter = new tracingExporterModule[tracingExporter.class](tracingConfig)
+  const exporter = new tracingExporterModule[tracingExporter.class](config)
   LOG._debug && LOG.debug('Using trace exporter:', exporter)
 
   return exporter

lib/tracing/trace.js

@@ -58,8 +58,7 @@ function _getParentSpan() {
       // root span gets request attributes
       _setAttributes(parent, _getRequestAttributes())
       if (HRTIME) parent.startTime = cds.context.http?.req?.__hrnow || _hrnow()
-      if (ADJUST_ROOT_NAME && parent.attributes[ATTR_URL_PATH])
-        parent.name += ' ' + parent.attributes[ATTR_URL_PATH]
+      if (ADJUST_ROOT_NAME && parent.attributes[ATTR_URL_PATH]) parent.name += ' ' + parent.attributes[ATTR_URL_PATH]
     }
     if (!parent?._is_async) cds.context._otelctx.setValue(cds.context._otelKey, parent)
   }

test/bookshop/lib/MySimpleLogRecordProcessor.js

@@ -0,0 +1,9 @@
+const { SimpleLogRecordProcessor } = require('@opentelemetry/sdk-logs')
+
+class MySimpleLogRecordProcessor extends SimpleLogRecordProcessor {
+  onEmit(logRecord) {
+    return super.onEmit(logRecord)
+  }
+}
+
+module.exports = { MySimpleLogRecordProcessor }

test/logging.test.js

@@ -1,8 +1,13 @@
 /* eslint-disable no-console */
 
+process.env.cds_log_format = 'json'
+
 process.env.cds_requires_telemetry_logging_exporter_module = '@opentelemetry/sdk-logs'
 process.env.cds_requires_telemetry_logging_exporter_class = 'ConsoleLogRecordExporter'
-process.env.cds_log_format = 'json'
+
+// experimental feature of the experimental feature!!!
+process.env.cds_requires_telemetry_logging_processor_module = './lib/MySimpleLogRecordProcessor.js'
+process.env.cds_requires_telemetry_logging_processor_class = 'MySimpleLogRecordProcessor'
 
 const cds = require('@sap/cds')
 const { expect, GET } = cds.test().in(__dirname + '/bookshop')