grafana/pkg/services/ngalert/ngalert.go

package ngalert

import (
	"context"
	"time"

	"github.com/grafana/grafana/pkg/services/quota"
	"golang.org/x/sync/errgroup"

	"github.com/grafana/grafana/pkg/services/ngalert/metrics"
	"github.com/grafana/grafana/pkg/services/ngalert/state"

	"github.com/benbjohnson/clock"

	"github.com/grafana/grafana/pkg/api/routing"
	"github.com/grafana/grafana/pkg/infra/log"
	"github.com/grafana/grafana/pkg/registry"
	"github.com/grafana/grafana/pkg/services/datasourceproxy"
	"github.com/grafana/grafana/pkg/services/datasources"
	"github.com/grafana/grafana/pkg/services/ngalert/api"
	"github.com/grafana/grafana/pkg/services/ngalert/eval"
	"github.com/grafana/grafana/pkg/services/ngalert/notifier"
	"github.com/grafana/grafana/pkg/services/ngalert/schedule"
	"github.com/grafana/grafana/pkg/services/ngalert/store"
	"github.com/grafana/grafana/pkg/services/sqlstore"
	"github.com/grafana/grafana/pkg/setting"
	"github.com/grafana/grafana/pkg/tsdb"
)

const (
	maxAttempts int64 = 3
	// scheduler interval
	// changing this value is discouraged
	// because this could cause existing alert definition
	// with intervals that are not exactly divided by this number
	// not to be evaluated
	baseIntervalSeconds = 10
	// default alert definition interval
	defaultIntervalSeconds int64 = 6 * baseIntervalSeconds
)

// AlertNG is the service for evaluating the condition of an alert definition.
type AlertNG struct {
	Cfg     *setting.Cfg `inject:""`
	Log     log.Logger
	Metrics *metrics.Metrics `inject:""`

	DatasourceCache datasources.CacheService                `inject:""`
	RouteRegister   routing.RouteRegister                   `inject:""`
	SQLStore        *sqlstore.SQLStore                      `inject:""`
	DataService     *tsdb.Service                           `inject:""`
	DataProxy       *datasourceproxy.DatasourceProxyService `inject:""`
	QuotaService    *quota.QuotaService                     `inject:""`
	schedule        schedule.ScheduleService
	stateManager    *state.Manager

	// Alerting notification services
	Alertmanager *notifier.Alertmanager
}

func init() {
	registry.RegisterService(&AlertNG{})
}

// Init initializes the AlertingService.
func (ng *AlertNG) Init() error {
	ng.Log = log.New("ngalert")
	baseInterval := baseIntervalSeconds * time.Second

	store := &store.DBstore{
		BaseInterval:           baseInterval,
		DefaultIntervalSeconds: defaultIntervalSeconds,
		SQLStore:               ng.SQLStore,
		Logger:                 ng.Log,
	}

	var err error
	ng.Alertmanager, err = notifier.New(ng.Cfg, store, ng.Metrics)
	if err != nil {
		return err
	}

	schedCfg := schedule.SchedulerCfg{
		C:                       clock.New(),
		BaseInterval:            baseInterval,
		Logger:                  log.New("ngalert.scheduler"),
		MaxAttempts:             maxAttempts,
		Evaluator:               eval.Evaluator{Cfg: ng.Cfg, Log: ng.Log},
		InstanceStore:           store,
		RuleStore:               store,
		AdminConfigStore:        store,
		Notifier:                ng.Alertmanager,
		Metrics:                 ng.Metrics,
		AdminConfigPollInterval: ng.Cfg.AdminConfigPollInterval,
	}

	ng.stateManager = state.NewManager(ng.Log, ng.Metrics, store, store)
	ng.schedule = schedule.NewScheduler(schedCfg, ng.DataService, ng.Cfg.AppURL, ng.stateManager)

	api := api.API{
		Cfg:              ng.Cfg,
		DatasourceCache:  ng.DatasourceCache,
		RouteRegister:    ng.RouteRegister,
		DataService:      ng.DataService,
		Schedule:         ng.schedule,
		DataProxy:        ng.DataProxy,
		QuotaService:     ng.QuotaService,
		InstanceStore:    store,
		RuleStore:        store,
		AlertingStore:    store,
		AdminConfigStore: store,
		Alertmanager:     ng.Alertmanager,
		StateManager:     ng.stateManager,
	}
	api.RegisterAPIEndpoints(ng.Metrics)

	return nil
}

// Run starts the scheduler and Alertmanager.
func (ng *AlertNG) Run(ctx context.Context) error {
	ng.Log.Debug("ngalert starting")
	ng.stateManager.Warm()

	children, subCtx := errgroup.WithContext(ctx)
	children.Go(func() error {
		return ng.schedule.Run(subCtx)
	})
	children.Go(func() error {
		return ng.Alertmanager.Run(subCtx)
	})
	return children.Wait()
}

// IsDisabled returns true if the alerting service is disable for this instance.
func (ng *AlertNG) IsDisabled() bool {
	if ng.Cfg == nil {
		return true
	}
	return !ng.Cfg.IsNgAlertEnabled()
}