MM-43918: freemium limit for storage (#20225)

Summary
Adds an API end point to return storage usage

Ticket Link
https://mattermost.atlassian.net/browse/MM-43918

app/app_iface.go

@@ -191,7 +191,8 @@ type AppIface interface {
 	// To get the plugins environment when the plugins are disabled, manually acquire the plugins
 	// lock instead.
 	GetPluginsEnvironment() *plugin.Environment
-	// GetPostsUsage returns "rounded off" total posts count like returns 900 instead of 987
+	// GetPostsUsage returns the total posts count rounded down to the most
+	// significant digit
 	GetPostsUsage() (int64, *model.AppError)
 	// GetProductNotices is called from the frontend to fetch the product notices that are relevant to the caller
 	GetProductNotices(c *request.Context, userID, teamID string, client model.NoticeClientType, clientVersion string, locale string) (model.NoticeMessages, *model.AppError)
@@ -204,6 +205,8 @@ type AppIface interface {
 	// GetSessionLengthInMillis returns the session length, in milliseconds,
 	// based on the type of session (Mobile, SSO, Web/LDAP).
 	GetSessionLengthInMillis(session *model.Session) int64
+	// GetStorageUsage returns the sum of files' sizes stored on this instance
+	GetStorageUsage() (int64, *model.AppError)
 	// GetSuggestions returns suggestions for user input.
 	GetSuggestions(c *request.Context, commandArgs *model.CommandArgs, commands []*model.Command, roleID string) []model.AutocompleteSuggestion
 	// GetTeamGroupUsers returns the users who are associated to the team via GroupTeams and GroupMembers.

app/opentracing/opentracing_layer.go

@@ -9095,6 +9095,28 @@ func (a *OpenTracingAppLayer) GetStatusesByIds(userIDs []string) (map[string]int
 	return resultVar0, resultVar1
 }
 
+func (a *OpenTracingAppLayer) GetStorageUsage() (int64, *model.AppError) {
+	origCtx := a.ctx
+	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetStorageUsage")
+
+	a.ctx = newCtx
+	a.app.Srv().Store.SetContext(newCtx)
+	defer func() {
+		a.app.Srv().Store.SetContext(origCtx)
+		a.ctx = origCtx
+	}()
+
+	defer span.Finish()
+	resultVar0, resultVar1 := a.app.GetStorageUsage()
+
+	if resultVar1 != nil {
+		span.LogFields(spanlog.Error(resultVar1))
+		ext.Error.Set(span, true)
+	}
+
+	return resultVar0, resultVar1
+}
+
 func (a *OpenTracingAppLayer) GetSuggestions(c *request.Context, commandArgs *model.CommandArgs, commands []*model.Command, roleID string) []model.AutocompleteSuggestion {
 	origCtx := a.ctx
 	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetSuggestions")

app/usage.go

@@ -45,7 +45,8 @@ func (ch *Channels) getIntegrationsUsage() (*model.IntegrationsUsage, *model.App
 	return &model.IntegrationsUsage{Enabled: count}, nil
 }
 
-// GetPostsUsage returns "rounded off" total posts count like returns 900 instead of 987
+// GetPostsUsage returns the total posts count rounded down to the most
+// significant digit
 func (a *App) GetPostsUsage() (int64, *model.AppError) {
 	count, err := a.Srv().Store.Post().AnalyticsPostCount(&model.PostCountOptions{ExcludeDeleted: true, UsersPostsOnly: true, AllowFromCache: true})
 	if err != nil {
@@ -55,6 +56,15 @@ func (a *App) GetPostsUsage() (int64, *model.AppError) {
 	return utils.RoundOffToZeroes(float64(count)), nil
 }
 
+// GetStorageUsage returns the sum of files' sizes stored on this instance
+func (a *App) GetStorageUsage() (int64, *model.AppError) {
+	usage, err := a.Srv().Store.FileInfo().GetStorageUsage(true, false)
+	if err != nil {
+		return 0, model.NewAppError("GetStorageUsage", "app.usage.get_storage_usage.app_error", nil, err.Error(), http.StatusInternalServerError)
+	}
+	return usage, nil
+}
+
 func (a *App) GetTeamsUsage() (*model.TeamsUsage, *model.AppError) {
 	usage := &model.TeamsUsage{}
 	includeDeleted := false
@@ -79,6 +89,5 @@ func (a *App) GetTeamsUsage() (*model.TeamsUsage, *model.AppError) {
 	}
 
 	usage.CloudArchived = int64(cloudArchivedTeamCount)
-
 	return usage, nil
 }