Remove usages of AppError on filesstore service (#15841)

* Remove usages of AppError on filesstore service

* Fixing a golint error

* Fixing shadowed variable

* Adding err.Error() to the NewAppError calls

* Fixing tests

* Adding missed translations

* Fix error handling and updating the translation that affects it

* Fixing two typos

api4/system.go

@@ -19,7 +19,6 @@ import (
 	"github.com/mattermost/mattermost-server/v5/mlog"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/services/cache"
-	"github.com/mattermost/mattermost-server/v5/services/filesstore"
 	"github.com/mattermost/mattermost-server/v5/services/upgrader"
 )
 
@@ -117,16 +116,8 @@ func getSystemPing(c *Context, w http.ResponseWriter, r *http.Request) {
 
 		filestoreStatusKey := "filestore_status"
 		s[filestoreStatusKey] = model.STATUS_OK
-		license := c.App.Srv().License()
-		backend, appErr := filesstore.NewFileBackend(&c.App.Config().FileSettings, license != nil && *license.Features.Compliance)
-		if appErr == nil {
-			appErr = backend.TestConnection()
-			if appErr != nil {
-				s[filestoreStatusKey] = model.STATUS_UNHEALTHY
-				s[model.STATUS] = model.STATUS_UNHEALTHY
-			}
-		} else {
-			mlog.Debug("Unable to get filestore for ping status.", mlog.Err(appErr))
+		appErr := c.App.TestFilesStoreConnection()
+		if appErr != nil {
 			s[filestoreStatusKey] = model.STATUS_UNHEALTHY
 			s[model.STATUS] = model.STATUS_UNHEALTHY
 		}
@@ -393,7 +384,7 @@ func testS3(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	err := filesstore.CheckMandatoryS3Fields(&cfg.FileSettings)
+	err := c.App.CheckMandatoryS3Fields(&cfg.FileSettings)
 	if err != nil {
 		c.Err = err
 		return
@@ -403,11 +394,7 @@ func testS3(c *Context, w http.ResponseWriter, r *http.Request) {
 		cfg.FileSettings.AmazonS3SecretAccessKey = c.App.Config().FileSettings.AmazonS3SecretAccessKey
 	}
 
-	license := c.App.Srv().License()
-	backend, appErr := filesstore.NewFileBackend(&cfg.FileSettings, license != nil && *license.Features.Compliance)
-	if appErr == nil {
-		appErr = backend.TestConnection()
-	}
+	appErr := c.App.TestFilesStoreConnectionWithConfig(&cfg.FileSettings)
 	if appErr != nil {
 		c.Err = appErr
 		return

api4/system_test.go

@@ -478,7 +478,7 @@ func TestS3TestConnection(t *testing.T) {
 		config.FileSettings.AmazonS3Bucket = model.NewString("Wrong_bucket")
 		_, resp = th.SystemAdminClient.TestS3Connection(&config)
 		CheckInternalErrorStatus(t, resp)
-		assert.Equal(t, "Unable to create bucket.", resp.Error.Message)
+		assert.Equal(t, "api.file.test_connection.app_error", resp.Error.Id)
 
 		*config.FileSettings.AmazonS3Bucket = "shouldcreatenewbucket"
 		_, resp = th.SystemAdminClient.TestS3Connection(&config)