From 53a0f8da276f8f8de23f3557d7ce69eff6e7b58a Mon Sep 17 00:00:00 2001
From: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Date: Thu, 28 Sep 2023 19:28:40 +0300
Subject: [PATCH] Add limiting ability to log fields (#24251)

---
 server/channels/app/platform/log.go          | 3 ++-
 server/go.mod                                | 2 +-
 server/go.sum                                | 4 ++--
 server/platform/services/imageproxy/local.go | 5 ++---
 server/public/model/config.go                | 5 +++++
 5 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/server/channels/app/platform/log.go b/server/channels/app/platform/log.go
index 5b1b7d28d6..8021267d7b 100644
--- a/server/channels/app/platform/log.go
+++ b/server/channels/app/platform/log.go
@@ -13,6 +13,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/mattermost/logr/v2"
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
 	"github.com/mattermost/mattermost/server/v8/config"
@@ -31,7 +32,7 @@ func (ps *PlatformService) initLogging() error {
 	// create the app logger if needed
 	if ps.logger == nil {
 		var err error
-		ps.logger, err = mlog.NewLogger()
+		ps.logger, err = mlog.NewLogger(logr.MaxFieldLen(*ps.Config().LogSettings.MaxFieldSize))
 		if err != nil {
 			return err
 		}
diff --git a/server/go.mod b/server/go.mod
index af0e15b9de..5b23edda01 100644
--- a/server/go.mod
+++ b/server/go.mod
@@ -37,7 +37,7 @@ require (
 	github.com/lib/pq v1.10.9
 	github.com/mattermost/go-i18n v1.11.1-0.20211013152124-5c415071e404
 	github.com/mattermost/gziphandler v0.0.1
-	github.com/mattermost/logr/v2 v2.0.16
+	github.com/mattermost/logr/v2 v2.0.18
 	github.com/mattermost/mattermost/server/public v0.0.9
 	github.com/mattermost/morph v1.0.5-0.20230511171014-e76e25978d56
 	github.com/mattermost/rsc v0.0.0-20160330161541-bbaefb05eaa0
diff --git a/server/go.sum b/server/go.sum
index d6b2621b84..908ad8ac08 100644
--- a/server/go.sum
+++ b/server/go.sum
@@ -443,8 +443,8 @@ github.com/mattermost/gziphandler v0.0.1 h1:uXHcXF5agnQ6bXabvpiwwwZOlCYoa7mKHH0l
 github.com/mattermost/gziphandler v0.0.1/go.mod h1:CvvZR7sXqhj81V2swXuQY7T04Ccc89u7W7pHNPKev8g=
 github.com/mattermost/ldap v0.0.0-20201202150706-ee0e6284187d h1:/RJ/UV7M5c7L2TQ0KNm4yZxxFvC1nvRz/gY/Daa35aI=
 github.com/mattermost/ldap v0.0.0-20201202150706-ee0e6284187d/go.mod h1:HLbgMEI5K131jpxGazJ97AxfPDt31osq36YS1oxFQPQ=
-github.com/mattermost/logr/v2 v2.0.16 h1:jnePX4cPskC3WDFvUardh/xZfxNdsFXbEERJQ1kUEDE=
-github.com/mattermost/logr/v2 v2.0.16/go.mod h1:1dm/YhTpozsqANXxo5Pi5zYLBsal2xY0pX+JZNbzYJY=
+github.com/mattermost/logr/v2 v2.0.18 h1:qiznuwwKckZJoGtBYc4Y9FAY97/oQwV1Pq9oO5qP5nk=
+github.com/mattermost/logr/v2 v2.0.18/go.mod h1:1dm/YhTpozsqANXxo5Pi5zYLBsal2xY0pX+JZNbzYJY=
 github.com/mattermost/mattermost/server/public v0.0.9 h1:Qsktgxx5dc8xVAUHP5MbSLi6Cf82iB/83r6S9bluHto=
 github.com/mattermost/mattermost/server/public v0.0.9/go.mod h1:sgXQrYzs+IJy51mB8E8OBljagk2u3YwQRoYlBH5goiw=
 github.com/mattermost/morph v1.0.5-0.20230511171014-e76e25978d56 h1:SjFYbWvmuf73d/KaYlnHosPpB3/k38ebr1WWw9X5XKc=
diff --git a/server/platform/services/imageproxy/local.go b/server/platform/services/imageproxy/local.go
index d1ac69c8c1..dba0d80f2d 100644
--- a/server/platform/services/imageproxy/local.go
+++ b/server/platform/services/imageproxy/local.go
@@ -152,13 +152,12 @@ func (backend *LocalBackend) ServeImage(w http.ResponseWriter, req *http.Request
 
 	resp, err := backend.client.Do(actualReq)
 	if err != nil {
-		msg := fmt.Sprintf("error fetching remote image: %v", err)
-		mlog.Warn(msg)
+		mlog.Warn("error fetching remote image", mlog.Err(err))
 		statusCode := http.StatusInternalServerError
 		if e, ok := err.(net.Error); ok && e.Timeout() {
 			statusCode = http.StatusGatewayTimeout
 		}
-		http.Error(w, msg, statusCode)
+		http.Error(w, fmt.Sprintf("error fetching remote image: %v", err), statusCode)
 		return
 	}
 	// close the original resp.Body, even if we wrap it in a NopCloser below
diff --git a/server/public/model/config.go b/server/public/model/config.go
index be823fabcf..0a799a356c 100644
--- a/server/public/model/config.go
+++ b/server/public/model/config.go
@@ -1276,6 +1276,7 @@ type LogSettings struct {
 	EnableSentry           *bool           `access:"environment_logging,write_restrictable,cloud_restrictable"` // telemetry: none
 	AdvancedLoggingJSON    json.RawMessage `access:"environment_logging,write_restrictable,cloud_restrictable"`
 	AdvancedLoggingConfig  *string         `access:"environment_logging,write_restrictable,cloud_restrictable"` // Deprecated: use `AdvancedLoggingJSON`
+	MaxFieldSize           *int            `access:"environment_logging,write_restrictable,cloud_restrictable"`
 }
 
 func NewLogSettings() *LogSettings {
@@ -1340,6 +1341,10 @@ func (s *LogSettings) SetDefaults() {
 	if s.AdvancedLoggingConfig == nil {
 		s.AdvancedLoggingConfig = NewString("")
 	}
+
+	if s.MaxFieldSize == nil {
+		s.MaxFieldSize = NewInt(2048)
+	}
 }
 
 // GetAdvancedLoggingConfig returns the advanced logging config as a []byte.