From 70ac1b054be58aa3c3c9057d78d72fe8c6a623ae Mon Sep 17 00:00:00 2001
From: Mariana Dima <mariana@elastic.co>
Date: Thu, 9 Dec 2021 17:08:53 +0100
Subject: [PATCH] Agent configuration overridden by default fleet config
 (#29297)

* replace config

* changelog

* add test on merge

* fmt
---
 x-pack/elastic-agent/CHANGELOG.next.asciidoc  |  1 +
 .../pkg/agent/application/application.go      |  4 +--
 .../pkg/agent/application/application_test.go | 33 +++++++++++++++++++
 x-pack/elastic-agent/pkg/agent/cmd/run.go     |  2 +-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/x-pack/elastic-agent/CHANGELOG.next.asciidoc b/x-pack/elastic-agent/CHANGELOG.next.asciidoc
index 385f87aa19d..b75a405d4bb 100644
--- a/x-pack/elastic-agent/CHANGELOG.next.asciidoc
+++ b/x-pack/elastic-agent/CHANGELOG.next.asciidoc
@@ -91,6 +91,7 @@
 - Snapshot artifact lookup will use agent.download proxy settings. {issue}27903[27903] {pull}27904[27904]
 - Fix lazy acker to only add new actions to the batch. {pull}27981[27981]
 - Allow HTTP metrics to run in bootstrap mode. Add ability to adjust timeouts for Fleet Server. {pull}28260[28260]
+- Fix agent configuration overwritten by default fleet config. {pull}29297[29297]
 
 ==== New features
 
diff --git a/x-pack/elastic-agent/pkg/agent/application/application.go b/x-pack/elastic-agent/pkg/agent/application/application.go
index e2f7a55ce3e..d0de160340d 100644
--- a/x-pack/elastic-agent/pkg/agent/application/application.go
+++ b/x-pack/elastic-agent/pkg/agent/application/application.go
@@ -39,10 +39,11 @@ type upgraderControl interface {
 }
 
 // New creates a new Agent and bootstrap the required subsystem.
-func New(log *logger.Logger, pathConfigFile string, reexec reexecManager, statusCtrl status.Controller, uc upgraderControl, agentInfo *info.AgentInfo) (Application, error) {
+func New(log *logger.Logger, reexec reexecManager, statusCtrl status.Controller, uc upgraderControl, agentInfo *info.AgentInfo) (Application, error) {
 	// Load configuration from disk to understand in which mode of operation
 	// we must start the elastic-agent, the mode of operation cannot be changed without restarting the
 	// elastic-agent.
+	pathConfigFile := paths.ConfigFile()
 	rawConfig, err := config.LoadFile(pathConfigFile)
 	if err != nil {
 		return nil, err
@@ -66,7 +67,6 @@ func createApplication(
 ) (Application, error) {
 	log.Info("Detecting execution mode")
 	ctx := context.Background()
-
 	cfg, err := configuration.NewFromConfig(rawConfig)
 	if err != nil {
 		return nil, err
diff --git a/x-pack/elastic-agent/pkg/agent/application/application_test.go b/x-pack/elastic-agent/pkg/agent/application/application_test.go
index 7c1975fef64..7ae0032d483 100644
--- a/x-pack/elastic-agent/pkg/agent/application/application_test.go
+++ b/x-pack/elastic-agent/pkg/agent/application/application_test.go
@@ -3,3 +3,36 @@
 // you may not use this file except in compliance with the Elastic License.
 
 package application
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/config"
+)
+
+func TestMergeFleetConfig(t *testing.T) {
+	cfg := map[string]interface{}{
+		"fleet": map[string]interface{}{
+			"enabled":        true,
+			"kibana":         map[string]interface{}{"host": "demo"},
+			"access_api_key": "123",
+		},
+		"agent": map[string]interface{}{
+			"grpc": map[string]interface{}{
+				"port": uint16(6790),
+			},
+		},
+	}
+
+	rawConfig := config.MustNewConfigFrom(cfg)
+	storage, conf, err := mergeFleetConfig(rawConfig)
+	require.NoError(t, err)
+	assert.NotNil(t, storage)
+	assert.NotNil(t, conf)
+	assert.Equal(t, conf.Fleet.Enabled, cfg["fleet"].(map[string]interface{})["enabled"])
+	assert.Equal(t, conf.Fleet.AccessAPIKey, cfg["fleet"].(map[string]interface{})["access_api_key"])
+	assert.Equal(t, conf.Settings.GRPC.Port, cfg["agent"].(map[string]interface{})["grpc"].(map[string]interface{})["port"].(uint16))
+}
diff --git a/x-pack/elastic-agent/pkg/agent/cmd/run.go b/x-pack/elastic-agent/pkg/agent/cmd/run.go
index 1c8c1dd4916..ba37febd674 100644
--- a/x-pack/elastic-agent/pkg/agent/cmd/run.go
+++ b/x-pack/elastic-agent/pkg/agent/cmd/run.go
@@ -142,7 +142,7 @@ func run(streams *cli.IOStreams, override cfgOverrider) error {
 	}
 	defer control.Stop()
 
-	app, err := application.New(logger, pathConfigFile, rex, statusCtrl, control, agentInfo)
+	app, err := application.New(logger, rex, statusCtrl, control, agentInfo)
 	if err != nil {
 		return err
 	}