From f33940fa066911207d28d63f61d3f728f89e4ea3 Mon Sep 17 00:00:00 2001
From: Stephen Belanger <stephen.belanger@elastic.co>
Date: Fri, 19 Oct 2018 12:03:31 -0700
Subject: [PATCH] feat(http): split disabling of spans from transactions

Fixes #434
---
 lib/config.js                       |  9 ++++++---
 lib/instrumentation/modules/http.js | 13 ++++++++-----
 test/config.js                      |  3 ++-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/lib/config.js b/lib/config.js
index 7b2ea021c51..bdd2f904642 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -53,7 +53,8 @@ var DEFAULTS = {
   transactionMaxSpans: 500,
   transactionSampleRate: 1.0,
   serverTimeout: '30s',
-  disableInstrumentations: []
+  disableInstrumentations: [],
+  monitorIncomingHTTPRequests: true
 }
 
 var ENV_TABLE = {
@@ -88,7 +89,8 @@ var ENV_TABLE = {
   transactionSampleRate: 'ELASTIC_APM_TRANSACTION_SAMPLE_RATE',
   serverTimeout: 'ELASTIC_APM_SERVER_TIMEOUT',
   disableInstrumentations: 'ELASTIC_APM_DISABLE_INSTRUMENTATIONS',
-  payloadLogFile: 'ELASTIC_APM_PAYLOAD_LOG_FILE'
+  payloadLogFile: 'ELASTIC_APM_PAYLOAD_LOG_FILE',
+  monitorIncomingHTTPRequests: 'ELASTIC_APM_MONITOR_INCOMING_HTTP_REQUESTS'
 }
 
 var BOOL_OPTS = [
@@ -99,7 +101,8 @@ var BOOL_OPTS = [
   'captureSpanStackTraces',
   'errorOnAbortedRequests',
   'instrument',
-  'asyncHooks'
+  'asyncHooks',
+  'monitorIncomingHTTPRequests'
 ]
 
 var NUM_OPTS = [
diff --git a/lib/instrumentation/modules/http.js b/lib/instrumentation/modules/http.js
index 50ee086d0d5..e1168647d4a 100644
--- a/lib/instrumentation/modules/http.js
+++ b/lib/instrumentation/modules/http.js
@@ -4,16 +4,19 @@ var httpShared = require('../http-shared')
 var shimmer = require('../shimmer')
 
 module.exports = function (http, agent, version, enabled) {
+  if (agent._conf.monitorIncomingHTTPRequests) {
+    agent.logger.debug('shimming http.Server.prototype.emit function')
+    shimmer.wrap(http && http.Server && http.Server.prototype, 'emit', httpShared.instrumentRequest(agent, 'http'))
+
+    agent.logger.debug('shimming http.ServerResponse.prototype.writeHead function')
+    shimmer.wrap(http && http.ServerResponse && http.ServerResponse.prototype, 'writeHead', wrapWriteHead)
+  }
+
   if (!enabled) return http
-  agent.logger.debug('shimming http.Server.prototype.emit function')
-  shimmer.wrap(http && http.Server && http.Server.prototype, 'emit', httpShared.instrumentRequest(agent, 'http'))
 
   agent.logger.debug('shimming http.request function')
   shimmer.wrap(http, 'request', httpShared.traceOutgoingRequest(agent, 'http'))
 
-  agent.logger.debug('shimming http.ServerResponse.prototype.writeHead function')
-  shimmer.wrap(http && http.ServerResponse && http.ServerResponse.prototype, 'writeHead', wrapWriteHead)
-
   return http
 
   function wrapWriteHead (original) {
diff --git a/test/config.js b/test/config.js
index fbbad17e173..bda5799749f 100644
--- a/test/config.js
+++ b/test/config.js
@@ -50,7 +50,8 @@ var optionFixtures = [
   ['transactionMaxSpans', 'TRANSACTION_MAX_SPANS', 500],
   ['transactionSampleRate', 'TRANSACTION_SAMPLE_RATE', 1.0],
   ['serverTimeout', 'SERVER_TIMEOUT', 30],
-  ['disableInstrumentations', 'DISABLE_INSTRUMENTATIONS', []]
+  ['disableInstrumentations', 'DISABLE_INSTRUMENTATIONS', []],
+  ['monitorIncomingHTTPRequests', 'MONITOR_INCOMING_HTTP_REQUESTS', true]
 ]
 
 var falsyValues = [false, 'false']