From 986fdcccc88b76a7655cd5ffa23bd949569a8734 Mon Sep 17 00:00:00 2001
From: Selsabil Mabrouk <selsabil.mabrouk@gmail.com>
Date: Thu, 14 Dec 2023 17:17:13 +0100
Subject: [PATCH] Add filter on topic name for metric
 kafka_topic_log_dir_size_total_bytes

---
 minion/config_log_dirs.go      | 25 +++++++++++++++++++++++++
 minion/service.go              | 14 ++++++++++----
 minion/utils.go                | 18 ++++++++++++++++++
 prometheus/collect_log_dirs.go |  3 +++
 4 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/minion/config_log_dirs.go b/minion/config_log_dirs.go
index 6da208b..e461bb4 100644
--- a/minion/config_log_dirs.go
+++ b/minion/config_log_dirs.go
@@ -1,17 +1,42 @@
 package minion
 
+import (
+	"fmt"
+)
+
 type LogDirsConfig struct {
 	// Enabled specifies whether log dirs shall be scraped and exported or not. This should be disabled for clusters prior
 	// to version 1.0.0 as describing log dirs was not supported back then.
 	Enabled bool `koanf:"enabled"`
+	// AllowedTopics are regex strings of topic names whose topic metrics that shall be exported.
+	AllowedTopics []string `koanf:"allowedTopics"`
+
+	// IgnoredTopics are regex strings of topic names that shall be ignored/skipped when exporting metrics. Ignored topics
+	// take precedence over allowed topics.
+	IgnoredTopics []string `koanf:"ignoredTopics"`
 }
 
 // Validate if provided LogDirsConfig is valid.
 func (c *LogDirsConfig) Validate() error {
+	// Check whether each provided string is valid regex
+	for _, topic := range c.AllowedTopics {
+		_, err := compileRegex(topic)
+		if err != nil {
+			return fmt.Errorf("allowed topic string '%v' is not valid regex", topic)
+		}
+	}
+
+	for _, topic := range c.IgnoredTopics {
+		_, err := compileRegex(topic)
+		if err != nil {
+			return fmt.Errorf("ignored topic string '%v' is not valid regex", topic)
+		}
+	}
 	return nil
 }
 
 // SetDefaults for topic config
 func (c *LogDirsConfig) SetDefaults() {
 	c.Enabled = true
+	c.AllowedTopics = []string{"/.*/"}
 }
diff --git a/minion/service.go b/minion/service.go
index 84efae9..e8922e4 100644
--- a/minion/service.go
+++ b/minion/service.go
@@ -27,10 +27,12 @@ type Service struct {
 	cache        map[string]interface{}
 	cacheLock    sync.RWMutex
 
-	AllowedGroupIDsExpr []*regexp.Regexp
-	IgnoredGroupIDsExpr []*regexp.Regexp
-	AllowedTopicsExpr   []*regexp.Regexp
-	IgnoredTopicsExpr   []*regexp.Regexp
+	AllowedGroupIDsExpr      []*regexp.Regexp
+	IgnoredGroupIDsExpr      []*regexp.Regexp
+	AllowedTopicsExpr        []*regexp.Regexp
+	IgnoredTopicsExpr        []*regexp.Regexp
+	AllowedlogDirsTopicsExpr []*regexp.Regexp
+	IgnoredlogDirsTopicsExpr []*regexp.Regexp
 
 	client  *kgo.Client
 	storage *Storage
@@ -67,6 +69,8 @@ func NewService(cfg Config, logger *zap.Logger, kafkaSvc *kafka.Service, metrics
 	ignoredGroupIDsExpr, _ := compileRegexes(cfg.ConsumerGroups.IgnoredGroupIDs)
 	allowedTopicsExpr, _ := compileRegexes(cfg.Topics.AllowedTopics)
 	ignoredTopicsExpr, _ := compileRegexes(cfg.Topics.IgnoredTopics)
+	allowedlogDirsTopicsExpr, _ := compileRegexes(cfg.LogDirs.AllowedTopics)
+	ignoredlogDirsTopicsExpr, _ := compileRegexes(cfg.LogDirs.IgnoredTopics)
 
 	service := &Service{
 		Cfg:    cfg,
@@ -80,6 +84,8 @@ func NewService(cfg Config, logger *zap.Logger, kafkaSvc *kafka.Service, metrics
 		IgnoredGroupIDsExpr: ignoredGroupIDsExpr,
 		AllowedTopicsExpr:   allowedTopicsExpr,
 		IgnoredTopicsExpr:   ignoredTopicsExpr,
+		AllowedlogDirsTopicsExpr: allowedlogDirsTopicsExpr,
+		IgnoredlogDirsTopicsExpr: ignoredlogDirsTopicsExpr,
 
 		client:  client,
 		storage: storage,
diff --git a/minion/utils.go b/minion/utils.go
index 3049b8f..b18eeeb 100644
--- a/minion/utils.go
+++ b/minion/utils.go
@@ -42,6 +42,24 @@ func (s *Service) IsTopicAllowed(topicName string) bool {
 	return isAllowed
 }
 
+func (s *Service) IsLOgDirsTopicAllowed(topicName string) bool {
+	isAllowed := false
+	for _, regex := range s.AllowedlogDirsTopicsExpr {
+		if regex.MatchString(topicName) {
+			isAllowed = true
+			break
+		}
+	}
+
+	for _, regex := range s.IgnoredlogDirsTopicsExpr {
+		if regex.MatchString(topicName) {
+			isAllowed = false
+			break
+		}
+	}
+	return isAllowed
+}
+
 func compileRegex(expr string) (*regexp.Regexp, error) {
 	if strings.HasPrefix(expr, "/") && strings.HasSuffix(expr, "/") {
 		substr := expr[1 : len(expr)-1]
diff --git a/prometheus/collect_log_dirs.go b/prometheus/collect_log_dirs.go
index 7794f9c..7a7774c 100644
--- a/prometheus/collect_log_dirs.go
+++ b/prometheus/collect_log_dirs.go
@@ -39,6 +39,9 @@ func (e *Exporter) collectLogDirs(ctx context.Context, ch chan<- prometheus.Metr
 				continue
 			}
 			for _, topic := range dir.Topics {
+                if !e.minionSvc.IsLOgDirsTopicAllowed(topic.Topic) {
+                    continue
+                }
 				topicSize := int64(0)
 				for _, partition := range topic.Partitions {
 					topicSize += partition.Size