Add migrate repo archiver and packages storage support on command line (#20757)

* Add migrate repo archiver and packages storage support on command line

* Fix typo

* Use stdCtx

* Use packageblob and fix command description

* Add migrate packages unit tests

* Fix comment year

* Fix the migrate storage command line description

* Update cmd/migrate_storage.go

Co-authored-by: zeripath <art27@cantab.net>

* Update cmd/migrate_storage.go

Co-authored-by: zeripath <art27@cantab.net>

* Update cmd/migrate_storage.go

Co-authored-by: zeripath <art27@cantab.net>

* Fix test

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: zeripath <art27@cantab.net>

cmd/migrate_storage_test.go

@@ -0,0 +1,74 @@
+// Copyright 2022 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 cmd
+
+import (
+	"context"
+	"os"
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/models/packages"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	packages_module "code.gitea.io/gitea/modules/packages"
+	"code.gitea.io/gitea/modules/storage"
+	packages_service "code.gitea.io/gitea/services/packages"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMigratePackages(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	creator := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1})
+
+	content := "package main\n\nfunc main() {\nfmt.Println(\"hi\")\n}\n"
+	buf, err := packages_module.CreateHashedBufferFromReader(strings.NewReader(content), 1024)
+	assert.NoError(t, err)
+	defer buf.Close()
+
+	v, f, err := packages_service.CreatePackageAndAddFile(&packages_service.PackageCreationInfo{
+		PackageInfo: packages_service.PackageInfo{
+			Owner:       creator,
+			PackageType: packages.TypeGeneric,
+			Name:        "test",
+			Version:     "1.0.0",
+		},
+		Creator:           creator,
+		SemverCompatible:  true,
+		VersionProperties: map[string]string{},
+	}, &packages_service.PackageFileCreationInfo{
+		PackageFileInfo: packages_service.PackageFileInfo{
+			Filename: "a.go",
+		},
+		Data:   buf,
+		IsLead: true,
+	})
+	assert.NoError(t, err)
+	assert.NotNil(t, v)
+	assert.NotNil(t, f)
+
+	ctx := context.Background()
+
+	p, err := os.MkdirTemp(os.TempDir(), "migrated_packages")
+	assert.NoError(t, err)
+
+	dstStorage, err := storage.NewLocalStorage(
+		ctx,
+		storage.LocalStorageConfig{
+			Path: p,
+		})
+	assert.NoError(t, err)
+
+	err = migratePackages(ctx, dstStorage)
+	assert.NoError(t, err)
+
+	entries, err := os.ReadDir(p)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 2, len(entries))
+	assert.EqualValues(t, "01", entries[0].Name())
+	assert.EqualValues(t, "tmp", entries[1].Name())
+}