From bff06e031b82b1d1878ad810d2f4b1ac05980493 Mon Sep 17 00:00:00 2001
From: Lee Avital <leeavital@gmail.com>
Date: Tue, 16 Apr 2019 11:28:26 -0400
Subject: [PATCH] Merge pull request #293 from
 DataDog/lee.avital/dont_hardcode_expvar_port

Make process_config.expvar configurable
---
 cmd/agent/main_common.go                                 | 4 ++--
 config/config.go                                         | 2 ++
 config/config_test.go                                    | 2 ++
 .../testdata/TestDDAgentConfigYamlAndNetworkConfig.yaml  | 3 ++-
 config/yaml_config.go                                    | 9 +++++++++
 5 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/cmd/agent/main_common.go b/cmd/agent/main_common.go
index 253777a14..a756c8431 100644
--- a/cmd/agent/main_common.go
+++ b/cmd/agent/main_common.go
@@ -146,7 +146,7 @@ func runAgent(exit chan bool) {
 
 	if opts.info {
 		// using the debug port to get info to work
-		url := "http://localhost:6062/debug/vars"
+		url := fmt.Sprintf("http://localhost:%d/debug/vars", cfg.ProcessExpVarPort)
 		if err := Info(os.Stdout, cfg, url); err != nil {
 			os.Exit(1)
 		}
@@ -155,7 +155,7 @@ func runAgent(exit chan bool) {
 
 	// Run a profile server.
 	go func() {
-		http.ListenAndServe("localhost:6062", nil)
+		http.ListenAndServe(fmt.Sprintf("localhost:%d", cfg.ProcessExpVarPort), nil)
 	}()
 
 	cl, err := NewCollector(cfg)
diff --git a/config/config.go b/config/config.go
index e23b940a7..d29cedd90 100644
--- a/config/config.go
+++ b/config/config.go
@@ -68,6 +68,7 @@ type AgentConfig struct {
 	DDAgentBin         string
 	StatsdHost         string
 	StatsdPort         int
+	ProcessExpVarPort  int
 
 	// Network collection configuration
 	EnableNetworkTracing     bool
@@ -154,6 +155,7 @@ func NewDefaultAgentConfig() *AgentConfig {
 		AllowRealTime:      true,
 		HostName:           "",
 		Transport:          NewDefaultTransport(),
+		ProcessExpVarPort:  6062,
 
 		// Statsd for internal instrumentation
 		StatsdHost: "127.0.0.1",
diff --git a/config/config_test.go b/config/config_test.go
index ba207b841..9f90e0282 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -165,6 +165,7 @@ func TestDefaultConfig(t *testing.T) {
 	assert.Equal(os.Getenv("HOST_SYS"), "")
 	os.Setenv("DOCKER_DD_AGENT", "no")
 	assert.Equal(containerChecks, agentConfig.EnabledChecks)
+	assert.Equal(6062, agentConfig.ProcessExpVarPort)
 
 	os.Unsetenv("DOCKER_DD_AGENT")
 }
@@ -263,6 +264,7 @@ func TestAgentConfigYamlAndNetworkConfig(t *testing.T) {
 	assert.Equal(100, agentConfig.Windows.ArgsRefreshInterval)
 	assert.Equal(false, agentConfig.Windows.AddNewArgs)
 	assert.Equal(false, agentConfig.Scrubber.Enabled)
+	assert.Equal(5065, agentConfig.ProcessExpVarPort)
 
 	agentConfig, err = NewAgentConfig(
 		"test",
diff --git a/config/testdata/TestDDAgentConfigYamlAndNetworkConfig.yaml b/config/testdata/TestDDAgentConfigYamlAndNetworkConfig.yaml
index bd34ad345..7392375f9 100644
--- a/config/testdata/TestDDAgentConfigYamlAndNetworkConfig.yaml
+++ b/config/testdata/TestDDAgentConfigYamlAndNetworkConfig.yaml
@@ -11,4 +11,5 @@ process_config:
   windows:
     args_refresh_interval: 100
     add_new_args: false
-  scrub_args: false
\ No newline at end of file
+  scrub_args: false
+  expvar_port: 5065
\ No newline at end of file
diff --git a/config/yaml_config.go b/config/yaml_config.go
index 0d0c55d83..c7212c6c3 100644
--- a/config/yaml_config.go
+++ b/config/yaml_config.go
@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"github.com/pkg/errors"
 	"net/url"
 	"regexp"
 	"strings"
@@ -137,6 +138,14 @@ func (a *AgentConfig) loadProcessYamlConfig(path string) error {
 		}
 	}
 
+	if k := key(ns, "expvar_port"); config.Datadog.IsSet(k) {
+		port := config.Datadog.GetInt(k)
+		if port <= 0 {
+			return errors.Errorf("invalid %s -- %d", k, port)
+		}
+		a.ProcessExpVarPort = port
+	}
+
 	// Enable/Disable the DataScrubber to obfuscate process args
 	if scrubArgsKey := key(ns, "scrub_args"); config.Datadog.IsSet(scrubArgsKey) {
 		a.Scrubber.Enabled = config.Datadog.GetBool(scrubArgsKey)