* vmalert: introduce additional HTTP URL params per-group configuration
The new group field `params` allows to configure custom HTTP URL params
per each group. These params will be applied to every request before
executing rule's expression. Hot config reload is also supported.
Field `extra_filter_labels` was deprecated in favour of `params` field.
vmalert will print deprecation log message if config file contains
the deprecated field.
`params` fields are supported by both Prometheus and Graphite datasource types.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: provide more examples for `params` field
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: set higher priority for `params` setting
If there would be a conflict between URL params set in `datasource.url` flag
and params in group definition the latter will have higher priority.
Signed-off-by: hagen1778 <roman@victoriametrics.com>
* vmalert: support rules backfilling (aka `replay`)
vmalert can `replay` configured rules in the past
and backfill results via remote write protocol.
It supports MetricsQL/PromQL storage as data source,
and can backfill data to remote write compatible
storage.
Supports recording and alerting rules `replay`. See more
details in README.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/836
* vmalert: review fixes
* vmalert: readme fixes
