**What this PR does / why we need it**:
Sometimes we want to not just fail a querytee but also report results on
the comparison between expected and actual results. That's why querytee
is extended with special metrics to give more insights into the
differences.
**Checklist**
- [x] Reviewed the
[`CONTRIBUTING.md`](https://github.com/grafana/loki/blob/main/CONTRIBUTING.md)
guide (**required**)
- [ ] Documentation added
- [x] Tests updated
- [ ] `CHANGELOG.md` updated
- [ ] If the change is worth mentioning in the release notes, add
`add-to-release-notes` label
- [ ] Changes that require user attention or interaction to upgrade are
documented in `docs/sources/setup/upgrade/_index.md`
- [ ] For Helm chart changes bump the Helm chart version in
`production/helm/loki/Chart.yaml` and update
`production/helm/loki/CHANGELOG.md` and
`production/helm/loki/README.md`. [Example
PR](d10549e3ec)
The `io/ioutil` package has been deprecated in Go 1.16 (See
https://pkg.go.dev/io/ioutil). This PR replaces the existing `io/ioutil`
functions with their new definitions in `io` and `os` packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
* Fork Cortex `tools/querytee`.
* Use forked querytee instead of Cortex one.
* Add `loki/tools` to list of possible paths.
* Add opts to querytee proxy.
