api/rules: Add filtering on rule name/group/file

This commits adds the option of filtering rules by rule name, rule
group, or file. This brings the rule API closer in-line with the current
Prometheus api.

Signed-off-by: Jacob Baungard Hansen <jacobbaungard@redhat.com>

CHANGELOG.md

@@ -17,6 +17,8 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 
 ### Added
 
+- [#7560](https://github.com/thanos-io/thanos/pull/7560) Query: Added the possibility of filtering rules by rule_name, rule_group or file to HTTP api.
+
 ### Changed
 
 - [#7494](https://github.com/thanos-io/thanos/pull/7494) Ruler: remove trailing period from SRV records returned by discovery `dnsnosrva` lookups

pkg/api/query/v1.go

@@ -82,6 +82,9 @@ const (
 	LookbackDeltaParam       = "lookback_delta"
 	EngineParam              = "engine"
 	QueryAnalyzeParam        = "analyze"
+	RuleNameParam            = "rule_name[]"
+	RuleGroupParam           = "rule_group[]"
+	FileParam                = "file[]"
 )
 
 type PromqlEngineType string
@@ -1397,6 +1400,9 @@ func NewRulesHandler(client rules.UnaryClient, enablePartialResponse bool) func(
 			Type:                    rulespb.RulesRequest_Type(typ),
 			PartialResponseStrategy: ps,
 			MatcherString:           r.Form[MatcherParam],
+			RuleName:                r.Form[RuleNameParam],
+			RuleGroup:               r.Form[RuleGroupParam],
+			File:                    r.Form[FileParam],
 		}
 		tracing.DoInSpan(ctx, "retrieve_rules", func(ctx context.Context) {
 			groups, warnings, err = client.Rules(ctx, req)

pkg/rules/rules.go

@@ -70,7 +70,9 @@ func (rr *GRPCClient) Rules(ctx context.Context, req *rulespb.RulesRequest) (*ru
 		}
 	}
 
-	resp.groups = filterRules(resp.groups, matcherSets)
+	resp.groups = filterRulesByMatchers(resp.groups, matcherSets)
+	resp.groups = filterRulesByNamesAndFile(resp.groups, req.RuleName, req.RuleGroup, req.File)
+
 	// TODO(bwplotka): Move to SortInterface with equal method and heap.
 	resp.groups = dedupGroups(resp.groups)
 	for _, g := range resp.groups {
@@ -80,8 +82,57 @@ func (rr *GRPCClient) Rules(ctx context.Context, req *rulespb.RulesRequest) (*ru
 	return &rulespb.RuleGroups{Groups: resp.groups}, resp.warnings, nil
 }
 
-// filterRules filters rules in a group according to given matcherSets.
-func filterRules(ruleGroups []*rulespb.RuleGroup, matcherSets [][]*labels.Matcher) []*rulespb.RuleGroup {
+// filters rules by group name, rule name or file.
+func filterRulesByNamesAndFile(ruleGroups []*rulespb.RuleGroup, ruleName []string, ruleGroup []string, file []string) []*rulespb.RuleGroup {
+	if len(ruleName) == 0 && len(ruleGroup) == 0 && len(file) == 0 {
+		return ruleGroups
+	}
+
+	queryFormToSet := func(values []string) map[string]struct{} {
+		set := make(map[string]struct{}, len(values))
+		for _, v := range values {
+			set[v] = struct{}{}
+		}
+		return set
+	}
+
+	rnSet := queryFormToSet(ruleName)
+	rgSet := queryFormToSet(ruleGroup)
+	fSet := queryFormToSet(file)
+
+	rgs := make([]*rulespb.RuleGroup, 0, len(ruleGroups))
+	for _, grp := range ruleGroups {
+		if len(rgSet) > 0 {
+			if _, ok := rgSet[grp.Name]; !ok {
+				continue
+			}
+		}
+
+		if len(fSet) > 0 {
+			if _, ok := fSet[grp.File]; !ok {
+				continue
+			}
+		}
+
+		if len(rnSet) > 0 {
+			ruleCount := 0
+			for _, r := range grp.Rules {
+				if _, ok := rnSet[r.GetName()]; ok {
+					grp.Rules[ruleCount] = r
+					ruleCount++
+				}
+			}
+			grp.Rules = grp.Rules[:ruleCount]
+		}
+		if len(grp.Rules) > 0 {
+			rgs = append(rgs, grp)
+		}
+	}
+	return rgs
+}
+
+// filterRulesbyMatchers filters rules in a group according to given matcherSets.
+func filterRulesByMatchers(ruleGroups []*rulespb.RuleGroup, matcherSets [][]*labels.Matcher) []*rulespb.RuleGroup {
 	if len(matcherSets) == 0 {
 		return ruleGroups
 	}