fix(api): When querying api query on endpoint alerts return a json st…

…ruct with alerts in lowercase.

To be same result as prometheus api
Signed-off-by: audig <audic.gui@gmail.com>

docs(changelog): Add link to MR #5534

CHANGELOG.md

@@ -13,6 +13,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 
 ### Fixed
 - [#5502](https://github.com/thanos-io/thanos/pull/5502) Receive: Handle exemplar storage errors as conflict error.
+- [#5534](https://github.com/thanos-io/thanos/pull/5534) Query: Set struct return by query api alerts same as prometheus api
 
 ### Added
 

pkg/api/query/v1.go

@@ -794,7 +794,9 @@ func NewAlertsHandler(client rules.UnaryClient, enablePartialResponse bool) func
 			return nil, nil, &api.ApiError{Typ: api.ErrorInternal, Err: errors.Errorf("error retrieving rules: %v", err)}
 		}
 
-		var resp struct{ Alerts []*rulespb.AlertInstance }
+		var resp struct {
+			Alerts []*rulespb.AlertInstance `json:"alerts"`
+		}
 		for _, g := range groups.Groups {
 			for _, r := range g.Rules {
 				a := r.GetAlert()