[feature] Add admin media prune orphaned CLI command (#1146)

* add FilePath regex

* add `admin media prune orphaned` command

* add prune orphaned function to media manager

* don't mark flag as required

* document admin media prune orphaned cmd

* oh envparsing.sh you coy minx

cmd/gotosocial/action/admin/media/prune/orphaned.go

@@ -0,0 +1,72 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package prune
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/superseriousbusiness/gotosocial/cmd/gotosocial/action"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db/bundb"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/media"
+	gtsstorage "github.com/superseriousbusiness/gotosocial/internal/storage"
+)
+
+// Orphaned prunes orphaned media from storage.
+var Orphaned action.GTSAction = func(ctx context.Context) error {
+	dbService, err := bundb.NewBunDBService(ctx)
+	if err != nil {
+		return fmt.Errorf("error creating dbservice: %s", err)
+	}
+
+	storage, err := gtsstorage.AutoConfig()
+	if err != nil {
+		return fmt.Errorf("error creating storage backend: %w", err)
+	}
+
+	manager, err := media.NewManager(dbService, storage)
+	if err != nil {
+		return fmt.Errorf("error instantiating mediamanager: %s", err)
+	}
+
+	dry := config.GetAdminMediaPruneDryRun()
+
+	pruned, err := manager.PruneOrphaned(ctx, dry)
+	if err != nil {
+		return fmt.Errorf("error pruning: %s", err)
+	}
+
+	if dry {
+		log.Infof("DRY RUN: %d stored items are orphaned and eligible to be pruned", pruned)
+	} else {
+		log.Infof("%d stored items were orphaned and pruned", pruned)
+	}
+
+	if err := storage.Close(); err != nil {
+		return fmt.Errorf("error closing storage backend: %w", err)
+	}
+
+	if err := dbService.Stop(ctx); err != nil {
+		return fmt.Errorf("error closing dbservice: %s", err)
+	}
+
+	return nil
+}