MM-10417 Add local image proxy and enable by default (#9967)

* MM-10417 Add local image proxy and enable by default

* Remove unused function

* Add dependencies for willnorris/imageproxy

* Fixed compilation errors

* Lock to the master version of willnorris/imageproxy

* Fix atmos/camo proxy when no SiteURL is specified

* Re-add default values for deprecated settings

* Fix unit tests added by merge

* Pass imageproxy to App struct

* Remove unneeded locking when creating the image proxy

* Remove empty test file

model/config.go

@@ -174,6 +174,9 @@ const (
 
 	CLIENT_SIDE_CERT_CHECK_PRIMARY_AUTH   = "primary"
 	CLIENT_SIDE_CERT_CHECK_SECONDARY_AUTH = "secondary"
+
+	IMAGE_PROXY_TYPE_LOCAL      = "local"
+	IMAGE_PROXY_TYPE_ATMOS_CAMO = "atmos/camo"
 )
 
 var ServerTLSSupportedCiphers = map[string]uint16{
@@ -272,9 +275,9 @@ type ServiceSettings struct {
 	ExperimentalEnableDefaultChannelLeaveJoinMessages *bool
 	ExperimentalGroupUnreadChannels                   *string
 	ExperimentalChannelOrganization                   *bool
-	ImageProxyType                                    *string
-	ImageProxyURL                                     *string
-	ImageProxyOptions                                 *string
+	DEPRECATED_DO_NOT_USE_ImageProxyType              *string `json:"ImageProxyType"`    // This field is deprecated and must not be used.
+	DEPRECATED_DO_NOT_USE_ImageProxyURL               *string `json:"ImageProxyURL"`     // This field is deprecated and must not be used.
+	DEPRECATED_DO_NOT_USE_ImageProxyOptions           *string `json:"ImageProxyOptions"` // This field is deprecated and must not be used.
 	EnableAPITeamDeletion                             *bool
 	ExperimentalEnableHardenedMode                    *bool
 	EnableEmailInvitations                            *bool
@@ -550,16 +553,16 @@ func (s *ServiceSettings) SetDefaults() {
 		s.ExperimentalChannelOrganization = NewBool(experimentalUnreadEnabled)
 	}
 
-	if s.ImageProxyType == nil {
-		s.ImageProxyType = NewString("")
+	if s.DEPRECATED_DO_NOT_USE_ImageProxyType == nil {
+		s.DEPRECATED_DO_NOT_USE_ImageProxyType = NewString("")
 	}
 
-	if s.ImageProxyURL == nil {
-		s.ImageProxyURL = NewString("")
+	if s.DEPRECATED_DO_NOT_USE_ImageProxyURL == nil {
+		s.DEPRECATED_DO_NOT_USE_ImageProxyURL = NewString("")
 	}
 
-	if s.ImageProxyOptions == nil {
-		s.ImageProxyOptions = NewString("")
+	if s.DEPRECATED_DO_NOT_USE_ImageProxyOptions == nil {
+		s.DEPRECATED_DO_NOT_USE_ImageProxyOptions = NewString("")
 	}
 
 	if s.EnableAPITeamDeletion == nil {
@@ -1931,6 +1934,43 @@ func (s *TimezoneSettings) SetDefaults() {
 	}
 }
 
+type ImageProxySettings struct {
+	Enable                  *bool
+	ImageProxyType          *string
+	RemoteImageProxyURL     *string
+	RemoteImageProxyOptions *string
+}
+
+func (ips *ImageProxySettings) SetDefaults(ss ServiceSettings) {
+	if ips.Enable == nil {
+		ips.Enable = NewBool(true)
+	}
+
+	if ips.ImageProxyType == nil {
+		if ss.DEPRECATED_DO_NOT_USE_ImageProxyType == nil || *ss.DEPRECATED_DO_NOT_USE_ImageProxyType == "" {
+			ips.ImageProxyType = NewString(IMAGE_PROXY_TYPE_LOCAL)
+		} else {
+			ips.ImageProxyType = ss.DEPRECATED_DO_NOT_USE_ImageProxyType
+		}
+	}
+
+	if ips.RemoteImageProxyURL == nil {
+		if ss.DEPRECATED_DO_NOT_USE_ImageProxyURL == nil {
+			ips.RemoteImageProxyURL = NewString("")
+		} else {
+			ips.RemoteImageProxyURL = ss.DEPRECATED_DO_NOT_USE_ImageProxyURL
+		}
+	}
+
+	if ips.RemoteImageProxyOptions == nil {
+		if ss.DEPRECATED_DO_NOT_USE_ImageProxyOptions == nil {
+			ips.RemoteImageProxyOptions = NewString("")
+		} else {
+			ips.RemoteImageProxyOptions = ss.DEPRECATED_DO_NOT_USE_ImageProxyOptions
+		}
+	}
+}
+
 type ConfigFunc func() *Config
 
 type Config struct {
@@ -1966,6 +2006,7 @@ type Config struct {
 	PluginSettings        PluginSettings
 	DisplaySettings       DisplaySettings
 	TimezoneSettings      TimezoneSettings
+	ImageProxySettings    ImageProxySettings
 }
 
 func (o *Config) Clone() *Config {
@@ -2037,6 +2078,7 @@ func (o *Config) SetDefaults() {
 	o.MessageExportSettings.SetDefaults()
 	o.TimezoneSettings.SetDefaults()
 	o.DisplaySettings.SetDefaults()
+	o.ImageProxySettings.SetDefaults(o.ServiceSettings)
 }
 
 func (o *Config) IsValid() *AppError {
@@ -2108,6 +2150,10 @@ func (o *Config) IsValid() *AppError {
 		return err
 	}
 
+	if err := o.ImageProxySettings.isValid(); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -2392,16 +2438,6 @@ func (ss *ServiceSettings) isValid() *AppError {
 		return NewAppError("Config.IsValid", "model.config.is_valid.group_unread_channels.app_error", nil, "", http.StatusBadRequest)
 	}
 
-	switch *ss.ImageProxyType {
-	case "":
-	case "atmos/camo":
-		if *ss.ImageProxyOptions == "" {
-			return NewAppError("Config.IsValid", "model.config.is_valid.atmos_camo_image_proxy_options.app_error", nil, "", http.StatusBadRequest)
-		}
-	default:
-		return NewAppError("Config.IsValid", "model.config.is_valid.image_proxy_type.app_error", nil, "", http.StatusBadRequest)
-	}
-
 	return nil
 }
 
@@ -2521,6 +2557,27 @@ func (ds *DisplaySettings) isValid() *AppError {
 	return nil
 }
 
+func (ips *ImageProxySettings) isValid() *AppError {
+	if *ips.Enable {
+		switch *ips.ImageProxyType {
+		case IMAGE_PROXY_TYPE_LOCAL:
+			// No other settings to validate
+		case IMAGE_PROXY_TYPE_ATMOS_CAMO:
+			if *ips.RemoteImageProxyURL == "" {
+				return NewAppError("Config.IsValid", "model.config.is_valid.atmos_camo_image_proxy_url.app_error", nil, "", http.StatusBadRequest)
+			}
+
+			if *ips.RemoteImageProxyOptions == "" {
+				return NewAppError("Config.IsValid", "model.config.is_valid.atmos_camo_image_proxy_options.app_error", nil, "", http.StatusBadRequest)
+			}
+		default:
+			return NewAppError("Config.IsValid", "model.config.is_valid.image_proxy_type.app_error", nil, "", http.StatusBadRequest)
+		}
+	}
+
+	return nil
+}
+
 func (o *Config) GetSanitizeOptions() map[string]bool {
 	options := map[string]bool{}
 	options["fullname"] = o.PrivacySettings.ShowFullName