Update Prometheus; add matchers parameter to LabelValues on ingester

[replay]

This PR updates the Prometheus version vendored in Cortex to the latest version.

With the new Prometheus version the LabelValues() call on the Querier interface now has an additional matchers parameter (introduced here).
Unfortunately we won't be able to directly take advantage of this new parameter here, because in order to use it this struct which gets imported from Thanos will also need to be updated:

cortex/vendor/github.com/thanos-io/thanos/pkg/store/storepb/rpc.pb.go

Line 503 in d385f47

type LabelValuesRequest struct {

We also can't update the Prometheus version in Thanos first, because Thanos imports Querier implementations from Cortex, so if we'd update Prometheus in Thanos before updating it in Cortex then the imported Querier implementations wouldn't match the interface defined in Prometheus anymore.
My plan to solve this is to first update the Prometheus version in Cortex, without taking advantage of that new parameter in the LabelValues() call. Then update the Prometheus and the Cortex versions in Thanos. Then make another PR to Cortex which takes advantage of that new parameter.

The main thing I'm uncertain about here is how to deal with the fact that v1.NewAPI (here) now requires the second argument to be a storage.Storage, previously it was a storage.SampleAndChunkQueryable. Since the last argument that we pass into v1.NewAPI() (here) is now hard-coded to false I think it is acceptable to simply add the required methods to errorTranslateQueryable without implementing them, knowing that they will never be called, but I'd definitely be open to suggestions about how to do that in a better way.

[pstibrany]

The main thing I'm uncertain about here is how to deal with the fact that v1.NewAPI (here) now requires the second argument to be a storage.Storage, previously it was a storage.SampleAndChunkQueryable. Since the last argument that we pass into v1.NewAPI() (here) is now hard-coded to false I think it is acceptable to simply add the required methods to errorTranslateQueryable without implementing them, knowing that they will never be called, but I'd definitely be open to suggestions about how to do that in a better way.

I would suggest to keep errorTranslateQueryable as is (ie. reverting your change), and introduce new readOnlyStorage type that embeds storage.SampleAndChunkQueryable, and adds additional missing methods from Storage interface. Those missing methods should also return errors where appropriate (esp. Appender part). WDYT?

[replay]

I would suggest to keep errorTranslateQueryable as is (ie. reverting your change), and introduce new readOnlyStorage type that embeds storage.SampleAndChunkQueryable, and adds additional missing methods from Storage interface. Those missing methods should also return errors where appropriate (esp. Appender part). WDYT?

That sounds better indeed, I'll do that, thx

[replay]

@pstibrany i updated it, thanks for the suggestion

[codesome]

This might need to go into the next release to include this fix (affects timestamp() function with @ modifier). Nevermind, I see that the 1.7.0 rc does not include the @ modifier at all :) all good here

[pstibrany]

It is unfortunate that NewAPI takes Storage, which requires us to implement extra methods. I've sent PR prometheus/prometheus#8488 to Prometheus to be able to pass queryable and appendable separately. If it is merged quickly, then I'm fine with taking shortcuts in this PR and just implement bare-minimum (as it is now). However, if prometheus/prometheus#8488 isn't merged, then we should implement "errAppender" to return errors, as current implementation of readOnlyStorage.Appender() returning nil may cause panics. It's also not clear what we should be returning in StartTime, although API doesn't use this method currently.

Apart from that, this PR looks good.

[roidelapluie]

I will merge it on the other side :)

[pstibrany]

Since Prometheus PR 8488 is now merged, let's update Prometheus in this PR.

[replay]

Thx for that Prometheus change @pstibrany . I have update Prometheus in this branch again, and I also rebased onto the latest master.

[pracucci]

LGTM, thanks!

[pracucci]

LGTM, considering the store-gateway doesn't support it yet.

[pstibrany]

Good job, thank you!