Make Migrations Cancelable

models/migrations/migrations.go

@@ -265,6 +265,8 @@ var migrations = []Migration{
 	NewMigration("update reactions constraint", updateReactionConstraint),
 	// v160 -> v161
 	NewMigration("Add block on official review requests branch protection", addBlockOnOfficialReviewRequests),
+	// v161 -> v162
+	NewMigration("Add process field to task table", addProcessToTask),
 }
 
 // GetCurrentDBVersion returns the current db version

models/migrations/v161.go

@@ -0,0 +1,17 @@
+// Copyright 2020 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 migrations
+
+import (
+	"xorm.io/xorm"
+)
+
+func addProcessToTask(x *xorm.Engine) error {
+	type Task struct {
+		Process string // process GUID and PID
+	}
+
+	return x.Sync2(new(Task))
+}

models/task.go

@@ -31,6 +31,7 @@ type Task struct {
 	PayloadContent string             `xorm:"TEXT"`
 	Errors         string             `xorm:"TEXT"` // if task failed, saved the error reason
 	Created        timeutil.TimeStamp `xorm:"created"`
+	Process        string             // process GUID and PID
 }
 
 // LoadRepo loads repository of the task
@@ -114,6 +115,17 @@ func (task *Task) MigrateConfig() (*migration.MigrateOptions, error) {
 	return nil, fmt.Errorf("Task type is %s, not Migrate Repo", task.Type.Name())
 }
 
+// GUIDandPID return GUID and PID of a running task
+func (task *Task) GUIDandPID() (guid int64, pid int64) {
+	if task.Status != structs.TaskStatusRunning {
+		return 0, 0
+	}
+	if _, err := fmt.Sscanf(task.Process, "%d/%d", &guid, &pid); err != nil {
+		return 0, 0
+	}
+	return
+}
+
 // ErrTaskDoesNotExist represents a "TaskDoesNotExist" kind of error.
 type ErrTaskDoesNotExist struct {
 	ID     int64

modules/process/manager.go

@@ -15,6 +15,8 @@ import (
 	"sort"
 	"sync"
 	"time"
+
+	gouuid "github.com/google/uuid"
 )
 
 // TODO: This packages still uses a singleton for the Manager.
@@ -44,18 +46,27 @@ type Manager struct {
 
 	counter   int64
 	processes map[int64]*Process
+
+	// guid is a unique id for a gitea instance
+	guid int64
 }
 
 // GetManager returns a Manager and initializes one as singleton if there's none yet
 func GetManager() *Manager {
 	if manager == nil {
 		manager = &Manager{
 			processes: make(map[int64]*Process),
+			guid:      int64(gouuid.New().ID()),
 		}
 	}
 	return manager
 }
 
+// GUID return a unique id of a gitea instance
+func (pm *Manager) GUID() int64 {
+	return pm.guid
+}
+
 // Add a process to the ProcessManager and returns its PID.
 func (pm *Manager) Add(description string, cancel context.CancelFunc) int64 {
 	pm.mutex.Lock()

modules/task/migrate.go

@@ -102,7 +102,8 @@ func runMigrateTask(t *models.Task) (err error) {
 
 	t.StartTime = timeutil.TimeStampNow()
 	t.Status = structs.TaskStatusRunning
-	if err = t.UpdateCols("start_time", "status"); err != nil {
+	t.Process = fmt.Sprintf("%d/%d", process.GetManager().GUID(), pid)
+	if err = t.UpdateCols("start_time", "status", "process"); err != nil {
 		return
 	}
 

options/locale/locale_en-US.ini

@@ -760,6 +760,8 @@ migrate.migrate_items_options = Access Token is required to migrate additional i
 migrated_from = Migrated from <a href="%[1]s">%[2]s</a>
 migrated_from_fake = Migrated From %[1]s
 migrate.migrate = Migrate From %s
+migrate.cancelled = The migration has been cancelled.
+migrate.task_not_found = The migration task for %s not found.
 migrate.migrating = Migrating from <b>%s</b> ...
 migrate.migrating_failed = Migrating from <b>%s</b> failed.
 migrate.github.description = Migrating data from Github.com or Github Enterprise.

routers/repo/migrate.go

@@ -6,17 +6,22 @@
 package repo
 
 import (
+	"net/http"
 	"strings"
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/auth"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/migrations"
+	"code.gitea.io/gitea/modules/process"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/task"
+	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
+	repo_service "code.gitea.io/gitea/services/repository"
 )
 
 const (
@@ -188,3 +193,53 @@ func MigratePost(ctx *context.Context, form auth.MigrateRepoForm) {
 
 	handleMigrateError(ctx, ctxUser, err, "MigratePost", tpl, &form)
 }
+
+// CancelMigration cancels a running migration
+func CancelMigration(ctx *context.Context) {
+	if !ctx.Repo.IsAdmin() {
+		ctx.Error(http.StatusNotFound)
+		return
+	}
+
+	if ctx.Repo.Repository.Status != models.RepositoryBeingMigrated {
+		ctx.Error(http.StatusConflict, "repo already migrated")
+		return
+	}
+
+	guid := process.GetManager().GUID()
+	task, err := models.GetMigratingTask(ctx.Repo.Repository.ID)
+	if err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+	if task.Status != structs.TaskStatusRunning {
+		task.Status = structs.TaskStatusStopped
+		task.EndTime = timeutil.TimeStampNow()
+		task.RepoID = 0
+
+		if err = task.UpdateCols("status", "repo_id", "end_time"); err != nil {
+			log.Error("Task UpdateCols failed: %v", err)
+		}
+
+		if err := repo_service.DeleteRepository(ctx.User, ctx.Repo.Repository); err != nil {
+			ctx.ServerError("DeleteRepository", err)
+			return
+		}
+
+		ctx.Flash.Success(ctx.Tr("repo.migrate.cancelled"))
+		ctx.Redirect(ctx.Repo.Owner.DashboardLink())
+		return
+	}
+
+	tGUID, tPID := task.GUIDandPID()
+	if guid == tGUID {
+		log.Trace("Migration [%s] cancel PID [%d] ", ctx.Repo.Repository.FullName(), tPID)
+		process.GetManager().Cancel(tPID)
+		ctx.Flash.Success(ctx.Tr("repo.migrate.cancelled"))
+		ctx.Redirect(ctx.Repo.Owner.DashboardLink())
+		return
+	}
+
+	ctx.Flash.Error(ctx.Tr("repo.migrate.task_not_found", ctx.Repo.Repository.FullName()))
+	ctx.Redirect(ctx.Repo.Owner.DashboardLink())
+}

routers/routes/macaron.go

@@ -529,6 +529,7 @@ func RegisterMacaronRoutes(m *macaron.Macaron) {
 	m.Get("/:username/:reponame/releases/download/:vTag/:fileName", ignSignIn, context.RepoAssignment(), repo.MustBeNotEmpty, repo.RedirectDownload)
 
 	m.Group("/:username/:reponame", func() {
+		m.Post("/migrate/cancel", repo.CancelMigration)
 		m.Group("/settings", func() {
 			m.Combo("").Get(repo.Settings).
 				Post(bindIgnErr(auth.RepoSettingForm{}), repo.SettingsPost)

templates/repo/migrate/migrating.tmpl

@@ -29,6 +29,17 @@
 							</div>
 						</div>
 					</div>
+					{{if .Permission.IsAdmin}}
+						<div class="ui divider"></div>
+						<div class="item center">
+							<form action="{{.Link}}/migrate/cancel" method="post">
+								{{.CsrfTokenHtml}}
+								<button class="ui button" data-do="delete">
+									<span class="item text">{{.i18n.Tr "cancel"}}</span>
+								</button>
+							</form>
+						</div>
+					{{end}}
 				</div>
 			</div>
 		</div>