Add push to remote mirror repository (#15157)

* Added push mirror model.

* Integrated push mirror into queue.

* Moved methods into own file.

* Added basic implementation.

* Mirror wiki too.

* Removed duplicated method.

* Get url for different remotes.

* Added migration.

* Unified remote url access.

* Add/Remove push mirror remotes.

* Prevent hangs with missing credentials.

* Moved code between files.

* Changed sanitizer interface.

* Added push mirror backend methods.

* Only update the mirror remote.

* Limit refs on push.

* Added UI part.

* Added missing table.

* Delete mirror if repository gets removed.

* Changed signature. Handle object errors.

* Added upload method.

* Added "upload" unit tests.

* Added transfer adapter unit tests.

* Send correct headers.

* Added pushing of LFS objects.

* Added more logging.

* Simpler body handling.

* Process files in batches to reduce HTTP calls.

* Added created timestamp.

* Fixed invalid column name.

* Changed name to prevent xorm auto setting.

* Remove table header im empty.

* Strip exit code from error message.

* Added docs page about mirroring.

* Fixed date.

* Fixed merge errors.

* Moved test to integrations.

* Added push mirror test.

* Added test.

models/repo_pushmirror_test.go

@@ -0,0 +1,49 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"testing"
+	"time"
+
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPushMirrorsIterate(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+
+	now := timeutil.TimeStampNow()
+
+	InsertPushMirror(&PushMirror{
+		RemoteName:     "test-1",
+		LastUpdateUnix: now,
+		Interval:       1,
+	})
+
+	long, _ := time.ParseDuration("24h")
+	InsertPushMirror(&PushMirror{
+		RemoteName:     "test-2",
+		LastUpdateUnix: now,
+		Interval:       long,
+	})
+
+	InsertPushMirror(&PushMirror{
+		RemoteName:     "test-3",
+		LastUpdateUnix: now,
+		Interval:       0,
+	})
+
+	time.Sleep(1 * time.Millisecond)
+
+	PushMirrorsIterate(func(idx int, bean interface{}) error {
+		m, ok := bean.(*PushMirror)
+		assert.True(t, ok)
+		assert.Equal(t, "test-1", m.RemoteName)
+		assert.Equal(t, m.RemoteName, m.GetRemoteName())
+		return nil
+	})
+}