This commit fixes a bug where we did not send resolved alerts to Alertmanager for resolved alert instances. This meant that resolved notifications did not have the annotations from the resolved state, and a result did not also have the resolved screenshot.
This commit adds a pkg/services/screenshot package for taking and uploading screenshots of Grafana dashboards. It supports taking screenshots of both dashboards and individual panels within a dashboard, using the rendering service.
The screenshot package has the following services, most of which can be composed:
BrowserScreenshotService (Takes screenshots with headless Chrome)
CachableScreenshotService (Caches screenshots taken with another service such as BrowserScreenshotService)
NoopScreenshotService (A no-op screenshot service for tests)
SingleFlightScreenshotService (Prevents duplicate screenshots when taking screenshots of the same dashboard or panel in parallel)
ScreenshotUnavailableService (A screenshot service that returns ErrScreenshotsUnavailable)
UploadingScreenshotService (A screenshot service that uploads taken screenshots)
The screenshot package does not support wire dependency injection yet. ngalert constructs its own version of the service. See https://github.com/grafana/grafana/issues/49296
This PR also adds an ImageScreenshotService to ngAlert. This is used to take screenshots with a screenshotservice and then store their location reference for use by alert instances and notifiers.
* do not suppress NoData state
* extract conversion of state to postable alert + tests
* create a special alert instance if nodata
* use NoData when converting from Keep Last State instead of Alerting
* add silence during migration if NoData is mapped to KeepLastState.
* Alerting: Fix alert flapping in the alertmanager
fixes a bug that caused Alerts that are evaluated at low intervals (sub 1 minute), to flap in the Alertmanager.
Mostly due to a combination of `EndsAt` and resend delay.
The Alertmanager uses `EndsAt` as a heuristic to know whenever it should resolve a firing alert, in the case that it hasn't heard
back from the alert generation system.
Because grafana sent the alert with an `EndsAt` which is equal to the `For` of the alert itself,
and we had a hard-coded 1 minute re-send delay (only applicable to firing alerts) this meant that a firing alert would resolve in the Alertmanager before we re-notify that it still firing.
This commit, increases the `EndsAt` by 3x the the resend delay or alert interval (depending on which one is higher). The resendDelay has been decreased to 30 seconds.
George Robinson
Joe Blubaugh
Yuriy Tseretyan
gotjosh
Kyle Brandt
David Parrott