[feature] persist worker queues to db (#3042)

* persist queued worker tasks to database on shutdown, fill worker queues from database on startup

* ensure the tasks are sorted by creation time before pushing them

* add migration to insert WorkerTask{} into database, add test for worker task persistence

* add test for recovering worker queues from database

* quick tweak

* whoops we ended up with double cleaner job scheduling

* insert each task separately, because bun is throwing some reflection error??

* add specific checking of cancelled worker contexts

* add http request signing to deliveries recovered from database

* add test for outgoing public key ID being correctly set on delivery

* replace select with Queue.PopCtx()

* get rid of loop now we don't use it

* remove field now we don't use it

* ensure that signing func is set

* header values weren't being copied over :facepalm:

* use ptr for httpclient.Request in delivery

* move worker queue filling to later in server init process

* fix rebase issues

* make logging less shouty

* use slices.Delete() instead of copying / reslicing

* have database return tasks in ascending order instead of sorting them

* add a 1 minute timeout to persisting worker queues

5 files changed, 149 insertions, 0 deletions

diff --git a/internal/db/bundb/bundb.go b/internal/db/bundb/bundb.go
index 070d4eb91..d5071d141 100644
--- a/internal/db/bundb/bundb.go
+++ b/internal/db/bundb/bundb.go
@@ -84,6 +84,7 @@ type DBService struct {
 	db.Timeline
 	db.User
 	db.Tombstone
+	db.WorkerTask
 	db *bun.DB
 }
 
@@ -302,6 +303,9 @@ func NewBunDBService(ctx context.Context, state *state.State) (db.DB, error) {
 			db:    db,
 			state: state,
 		},
+		WorkerTask: &workerTaskDB{
+			db: db,
+		},
 		db: db,
 	}
 
diff --git a/internal/db/bundb/migrations/20240617134210_add_worker_tasks_table.go b/internal/db/bundb/migrations/20240617134210_add_worker_tasks_table.go
new file mode 100644
index 000000000..3b0ebcfd8
--- /dev/null
+++ b/internal/db/bundb/migrations/20240617134210_add_worker_tasks_table.go
@@ -0,0 +1,51 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 migrations
+
+import (
+	"context"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/uptrace/bun"
+)
+
+func init() {
+	up := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			// WorkerTask table.
+			if _, err := tx.
+				NewCreateTable().
+				Model(&gtsmodel.WorkerTask{}).
+				IfNotExists().
+				Exec(ctx); err != nil {
+				return err
+			}
+			return nil
+		})
+	}
+
+	down := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			return nil
+		})
+	}
+
+	if err := Migrations.Register(up, down); err != nil {
+		panic(err)
+	}
+}
diff --git a/internal/db/bundb/workertask.go b/internal/db/bundb/workertask.go
new file mode 100644
index 000000000..eec51530d
--- /dev/null
+++ b/internal/db/bundb/workertask.go
@@ -0,0 +1,58 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 bundb
+
+import (
+	"context"
+	"errors"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/uptrace/bun"
+)
+
+type workerTaskDB struct{ db *bun.DB }
+
+func (w *workerTaskDB) GetWorkerTasks(ctx context.Context) ([]*gtsmodel.WorkerTask, error) {
+	var tasks []*gtsmodel.WorkerTask
+	if err := w.db.NewSelect().
+		Model(&tasks).
+		OrderExpr("? ASC", bun.Ident("created_at")).
+		Scan(ctx); err != nil {
+		return nil, err
+	}
+	return tasks, nil
+}
+
+func (w *workerTaskDB) PutWorkerTasks(ctx context.Context, tasks []*gtsmodel.WorkerTask) error {
+	var errs []error
+	for _, task := range tasks {
+		_, err := w.db.NewInsert().Model(task).Exec(ctx)
+		if err != nil {
+			errs = append(errs, err)
+		}
+	}
+	return errors.Join(errs...)
+}
+
+func (w *workerTaskDB) DeleteWorkerTaskByID(ctx context.Context, id uint) error {
+	_, err := w.db.NewDelete().
+		Table("worker_tasks").
+		Where("? = ?", bun.Ident("id"), id).
+		Exec(ctx)
+	return err
+}
diff --git a/internal/db/db.go b/internal/db/db.go
index 4b2152732..cd621871a 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -56,4 +56,5 @@ type DB interface {
 	Timeline
 	User
 	Tombstone
+	WorkerTask
 }
diff --git a/internal/db/workertask.go b/internal/db/workertask.go
new file mode 100644
index 000000000..0276f231a
--- /dev/null
+++ b/internal/db/workertask.go
@@ -0,0 +1,35 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 db
+
+import (
+	"context"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+type WorkerTask interface {
+	// GetWorkerTasks fetches all persisted worker tasks from the database.
+	GetWorkerTasks(ctx context.Context) ([]*gtsmodel.WorkerTask, error)
+
+	// PutWorkerTasks persists the given worker tasks to the database.
+	PutWorkerTasks(ctx context.Context, tasks []*gtsmodel.WorkerTask) error
+
+	// DeleteWorkerTask deletes worker task with given ID from database.
+	DeleteWorkerTaskByID(ctx context.Context, id uint) error
+}