grafana/pkg/services/ngalert/image/service.go
2022-06-29 09:39:24 +01:00

127 lines
4.1 KiB
Go

package image
import (
"context"
"errors"
"fmt"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/grafana/grafana/pkg/components/imguploader"
"github.com/grafana/grafana/pkg/services/dashboards"
"github.com/grafana/grafana/pkg/services/ngalert/models"
"github.com/grafana/grafana/pkg/services/ngalert/store"
"github.com/grafana/grafana/pkg/services/rendering"
"github.com/grafana/grafana/pkg/services/screenshot"
"github.com/grafana/grafana/pkg/setting"
)
//go:generate mockgen -destination=mock.go -package=image github.com/grafana/grafana/pkg/services/ngalert/image ImageService
type ImageService interface {
// NewImage returns a new image for the alert instance.
NewImage(ctx context.Context, r *models.AlertRule) (*models.Image, error)
}
var (
// ErrNoDashboard is returned when the alert rule does not have a dashboard.
ErrNoDashboard = errors.New("no dashboard")
// ErrNoPanel is returned when the alert rule does not have a panel in a dashboard.
ErrNoPanel = errors.New("no panel")
)
const (
screenshotTimeout = 10 * time.Second
screenshotCacheTTL = 60 * time.Second
)
// ScreenshotImageService takes screenshots of the panel for an alert rule and
// saves the image in the store. The image contains a unique token that can be
// passed as an annotation or label to the Alertmanager.
type ScreenshotImageService struct {
screenshots screenshot.ScreenshotService
store store.ImageStore
}
func NewScreenshotImageService(screenshots screenshot.ScreenshotService, store store.ImageStore) ImageService {
return &ScreenshotImageService{
screenshots: screenshots,
store: store,
}
}
// NewScreenshotImageServiceFromCfg returns a new ScreenshotImageService
// from the configuration.
func NewScreenshotImageServiceFromCfg(cfg *setting.Cfg, metrics prometheus.Registerer,
db *store.DBstore, ds dashboards.DashboardService, rs rendering.Service) (ImageService, error) {
if !cfg.UnifiedAlerting.Screenshots.Capture {
return &ScreenshotImageService{
screenshots: &screenshot.ScreenshotUnavailableService{},
}, nil
}
s := screenshot.NewBrowserScreenshotService(ds, rs)
if cfg.UnifiedAlerting.Screenshots.UploadExternalImageStorage {
u, err := imguploader.NewImageUploader()
if err != nil {
return nil, fmt.Errorf("failed to initialize uploading screenshot service: %w", err)
}
s = screenshot.NewUploadingScreenshotService(metrics, s, u)
}
s = screenshot.NewRateLimitScreenshotService(s, cfg.UnifiedAlerting.Screenshots.MaxConcurrentScreenshots)
s = screenshot.NewSingleFlightScreenshotService(s)
s = screenshot.NewCachableScreenshotService(metrics, screenshotCacheTTL, s)
s = screenshot.NewObservableScreenshotService(metrics, s)
return &ScreenshotImageService{
store: db,
screenshots: s,
}, nil
}
// NewImage returns a screenshot of the panel for the alert rule. It returns
// ErrNoDashboard if the alert rule does not have a dashboard and ErrNoPanel
// when the alert rule does not have a panel in a dashboard.
func (s *ScreenshotImageService) NewImage(ctx context.Context, r *models.AlertRule) (*models.Image, error) {
if r.DashboardUID == nil {
return nil, ErrNoDashboard
}
if r.PanelID == nil || *r.PanelID == 0 {
return nil, ErrNoPanel
}
screenshot, err := s.screenshots.Take(ctx, screenshot.ScreenshotOptions{
Timeout: screenshotTimeout,
DashboardUID: *r.DashboardUID,
PanelID: *r.PanelID,
})
// TODO: Check for screenshot upload failures. These images should still be
// stored because we have a local disk path that could be useful.
if err != nil {
return nil, err
}
v := models.Image{
Path: screenshot.Path,
URL: screenshot.URL,
}
if err := s.store.SaveImage(ctx, &v); err != nil {
return nil, fmt.Errorf("failed to save image: %w", err)
}
return &v, nil
}
type NotAvailableImageService struct{}
func (s *NotAvailableImageService) NewImage(ctx context.Context, r *models.AlertRule) (*models.Image, error) {
return nil, screenshot.ErrScreenshotsUnavailable
}
type NoopImageService struct{}
func (s *NoopImageService) NewImage(ctx context.Context, r *models.AlertRule) (*models.Image, error) {
return &models.Image{}, nil
}