* pkg/web: store http.Handler internally
* pkg/web: remove injection
Removes any injection code from pkg/web.
It already was no longer functional, as we already only injected into
`http.Handler`, meaning we only inject ctx.Req and ctx.Resp.
Any other types (*Context, *ReqContext) were already accessed using the
http.Request.Context.Value() method.
* *: remove type mappings
Removes any call to the previously removed TypeMapper, as those were
non-functional already.
* pkg/web: remove Context.Invoke
was no longer used outside of pkg/web and also no longer functional
* remove not used code:
- remove offset in ticket because it is not used
- remove unused ticker and scheduler methods
* use duration for interval
* add metrics grafana_alerting_ticker_last_consumed_tick_timestamp_seconds, grafana_alerting_ticker_next_tick_timestamp_seconds, grafana_alerting_ticker_interval_seconds
* pass url parameters through context.Context
* fix url param names without colon prefix
* change context params to vars
* replace url vars in tests using new api
* rename vars to params
* add some comments
* rename seturlvars to seturlparams
* Alerting: Refactor & fix unified alerting metrics structure
Fixes and refactors the metrics structure we have for the ngalert service. Now, each component has its own metric struct that includes the JUST the metrics it uses. Additionally, I have fixed the configuration metrics and added new metrics to determine if we have discovered and started all the necessary configurations of an instance.
This allows us to alert on `grafana_alerting_discovered_configurations - grafana_alerting_active_configurations != 0` to know whether an alertmanager instance did not start successfully.
Introduces org-level isolation for the Alertmanager and its components.
Silences, Alerts and Contact points are not separated by org and are not shared between them.
Co-authored with @davidmparrott and @papagian
