Refactor Cron and merge dashboard tasks (#10745)

* Refactor Cron and merge dashboard tasks

* Merge Cron and Dashboard tasks
* Make every cron task report a system notice on completion
* Refactor the creation of these tasks
* Ensure that execution counts of tasks is correct
* Allow cron tasks to be started from the cron page

* golangci-lint fixes

* Enforce that only one task with the same name can be registered

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix name check

Signed-off-by: Andrew Thornton <art27@cantab.net>

* as per @guillep2k

* as per @lafriks

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Add git.CommandContext variants

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

modules/cron/tasks_basic.go

@@ -0,0 +1,118 @@
+// 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 cron
+
+import (
+	"context"
+	"time"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/migrations"
+	repository_service "code.gitea.io/gitea/modules/repository"
+	mirror_service "code.gitea.io/gitea/services/mirror"
+)
+
+func registerUpdateMirrorTask() {
+	RegisterTaskFatal("update_mirrors", &BaseConfig{
+		Enabled:    true,
+		RunAtStart: false,
+		Schedule:   "@every 10m",
+	}, func(ctx context.Context, _ *models.User, _ Config) error {
+		return mirror_service.Update(ctx)
+	})
+}
+
+func registerRepoHealthCheck() {
+	type RepoHealthCheckConfig struct {
+		BaseConfig
+		Timeout time.Duration
+		Args    []string `delim:" "`
+	}
+	RegisterTaskFatal("repo_health_check", &RepoHealthCheckConfig{
+		BaseConfig: BaseConfig{
+			Enabled:    true,
+			RunAtStart: false,
+			Schedule:   "@every 24h",
+		},
+		Timeout: 60 * time.Second,
+		Args:    []string{},
+	}, func(ctx context.Context, _ *models.User, config Config) error {
+		rhcConfig := config.(*RepoHealthCheckConfig)
+		return repository_service.GitFsck(ctx, rhcConfig.Timeout, rhcConfig.Args)
+	})
+}
+
+func registerCheckRepoStats() {
+	RegisterTaskFatal("check_repo_stats", &BaseConfig{
+		Enabled:    true,
+		RunAtStart: true,
+		Schedule:   "@every 24h",
+	}, func(ctx context.Context, _ *models.User, _ Config) error {
+		return models.CheckRepoStats(ctx)
+	})
+}
+
+func registerArchiveCleanup() {
+	RegisterTaskFatal("archive_cleanup", &OlderThanConfig{
+		BaseConfig: BaseConfig{
+			Enabled:    true,
+			RunAtStart: true,
+			Schedule:   "@every 24h",
+		},
+		OlderThan: 24 * time.Hour,
+	}, func(ctx context.Context, _ *models.User, config Config) error {
+		acConfig := config.(*OlderThanConfig)
+		return models.DeleteOldRepositoryArchives(ctx, acConfig.OlderThan)
+	})
+}
+
+func registerSyncExternalUsers() {
+	RegisterTaskFatal("sync_external_users", &UpdateExistingConfig{
+		BaseConfig: BaseConfig{
+			Enabled:    true,
+			RunAtStart: false,
+			Schedule:   "@every 24h",
+		},
+		UpdateExisting: true,
+	}, func(ctx context.Context, _ *models.User, config Config) error {
+		realConfig := config.(*UpdateExistingConfig)
+		return models.SyncExternalUsers(ctx, realConfig.UpdateExisting)
+	})
+}
+
+func registerDeletedBranchesCleanup() {
+	RegisterTaskFatal("deleted_branches_cleanup", &OlderThanConfig{
+		BaseConfig: BaseConfig{
+			Enabled:    true,
+			RunAtStart: true,
+			Schedule:   "@every 24h",
+		},
+		OlderThan: 24 * time.Hour,
+	}, func(ctx context.Context, _ *models.User, config Config) error {
+		realConfig := config.(*OlderThanConfig)
+		models.RemoveOldDeletedBranches(ctx, realConfig.OlderThan)
+		return nil
+	})
+}
+
+func registerUpdateMigrationPosterID() {
+	RegisterTaskFatal("update_migration_poster_id", &BaseConfig{
+		Enabled:    true,
+		RunAtStart: true,
+		Schedule:   "@every 24h",
+	}, func(ctx context.Context, _ *models.User, _ Config) error {
+		return migrations.UpdateMigrationPosterID(ctx)
+	})
+}
+
+func initBasicTasks() {
+	registerUpdateMirrorTask()
+	registerRepoHealthCheck()
+	registerCheckRepoStats()
+	registerArchiveCleanup()
+	registerSyncExternalUsers()
+	registerDeletedBranchesCleanup()
+	registerUpdateMigrationPosterID()
+}