Sets the default sd-dns-resolver for ruler miekgdns (#5997)

Related to issue: #4204

Problem: in the PR #4519 the
default sd-dns-resolver for querier was set to miekgdns but this change
was never ported to ruler

Solution: this PR brings this default to ruler as well to make it
consistent

Signed-off-by: JoaoBraveCoding <jmarcal@redhat.com>

Signed-off-by: JoaoBraveCoding <jmarcal@redhat.com>

CHANGELOG.md

@@ -19,6 +19,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#5880](https://github.com/thanos-io/thanos/pull/5880) Query Frontend: Fixes some edge cases of query sharding analysis.
 - [#5893](https://github.com/thanos-io/thanos/pull/5893) Cache: Fixed redis client not respecting `SetMultiBatchSize` config value.
 - [#5966](https://github.com/thanos-io/thanos/pull/5966) Query: Fixed mint and maxt when selecting series for the `api/v1/series` HTTP endpoint.
+- [#5997](https://github.com/thanos-io/thanos/pull/5997) Rule: switch to miekgdns DNS resolver as the default one.
 
 ### Added
 

cmd/thanos/config.go

@@ -198,7 +198,7 @@ func (qc *queryConfig) registerFlag(cmd extkingpin.FlagClause) *queryConfig {
 	cmd.Flag("query.http-method", "HTTP method to use when sending queries. Possible options: [GET, POST]").
 		Default("POST").EnumVar(&qc.httpMethod, "GET", "POST")
 	cmd.Flag("query.sd-dns-resolver", "Resolver to use. Possible options: [golang, miekgdns]").
-		Default("golang").Hidden().StringVar(&qc.dnsSDResolver)
+		Default("miekgdns").Hidden().StringVar(&qc.dnsSDResolver)
 	cmd.Flag("query.default-step", "Default range query step to use. This is only used in stateless Ruler and alert state restoration.").
 		Default("1s").DurationVar(&qc.step)
 	return qc