From 4d436f40949f6a558f5d98af30fac619bbc96475 Mon Sep 17 00:00:00 2001
From: Saswata Mukherjee <saswataminsta@yahoo.com>
Date: Wed, 18 Dec 2024 17:37:22 +0000
Subject: [PATCH] Fix leaky goroutine on metrics-collector

Signed-off-by: Saswata Mukherjee <saswataminsta@yahoo.com>
---
 .../metrics/cmd/metrics-collector/main.go     |  4 +
 .../cmd/metrics-collector/main_test.go        | 97 +++++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/collectors/metrics/cmd/metrics-collector/main.go b/collectors/metrics/cmd/metrics-collector/main.go
index f86a41c38..68ebea551 100644
--- a/collectors/metrics/cmd/metrics-collector/main.go
+++ b/collectors/metrics/cmd/metrics-collector/main.go
@@ -722,6 +722,10 @@ func initShardedConfigs(o *Options, agent Agent) ([]*forwarder.Config, error) {
 }
 
 func runMultiWorkers(o *Options, cfg *forwarder.Config) error {
+	if o.WorkerNum > 1 {
+		return nil
+	}
+
 	for i := 1; i < int(o.WorkerNum); i++ {
 		opt := &Options{
 			From:                    o.From,
diff --git a/collectors/metrics/cmd/metrics-collector/main_test.go b/collectors/metrics/cmd/metrics-collector/main_test.go
index 5ee34be01..d8e8f4cda 100644
--- a/collectors/metrics/cmd/metrics-collector/main_test.go
+++ b/collectors/metrics/cmd/metrics-collector/main_test.go
@@ -5,6 +5,7 @@
 package main
 
 import (
+	"fmt"
 	stdlog "log"
 	"os"
 	"testing"
@@ -65,3 +66,99 @@ func TestMultiWorkers(t *testing.T) {
 	time.Sleep(1 * time.Second)
 
 }
+
+func TestSplitMatchersIntoShards(t *testing.T) {
+	tests := []struct {
+		name       string
+		matchers   []string
+		shardCount int
+		want       [][]string
+	}{
+		{
+			name:       "single shard",
+			matchers:   []string{"match1", "match2", "match3"},
+			shardCount: 1,
+			want:       [][]string{{"match1", "match2", "match3"}},
+		},
+		{
+			name:       "two shards",
+			matchers:   []string{"match1", "match2", "match3", "match4"},
+			shardCount: 2,
+			want: [][]string{
+				{"match1", "match3"},
+				{"match2", "match4"},
+			},
+		},
+		{
+			name:       "two shards",
+			matchers:   []string{"match1", "match2", "match3", "match4"},
+			shardCount: 6,
+			want: [][]string{
+				{"match1"},
+				{"match2"},
+				{"match3"},
+				{"match4"},
+			},
+		},
+		{
+			name:       "three shards",
+			matchers:   []string{"match1", "match2", "match3", "match4", "match5"},
+			shardCount: 3,
+			want: [][]string{
+				{"match1", "match4"},
+				{"match2", "match5"},
+				{"match3"},
+			},
+		},
+		{
+			name:       "more shards than matchers",
+			matchers:   []string{"match1", "match2"},
+			shardCount: 3,
+			want: [][]string{
+				{"match1"},
+				{"match2"},
+				{},
+			},
+		},
+		{
+			name:       "zero shards",
+			matchers:   []string{"match1", "match2", "match3"},
+			shardCount: 0,
+			want:       [][]string{{"match1", "match2", "match3"}},
+		},
+		{
+			name:       "negative shards",
+			matchers:   []string{"match1", "match2", "match3"},
+			shardCount: -1,
+			want:       [][]string{{"match1", "match2", "match3"}},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := splitMatchersIntoShards(tt.matchers, tt.shardCount)
+			fmt.Println(got)
+			// Check if number of shards matches
+			if len(got) != len(tt.want) {
+				t.Errorf("splitMatchersIntoShards() got %d shards, want %d shards",
+					len(got), len(tt.want))
+				return
+			}
+
+			// Check if each shard contains the expected matchers
+			for i := 0; i < len(got); i++ {
+				if len(got[i]) != len(tt.want[i]) {
+					t.Errorf("shard %d: got %d matchers, want %d matchers",
+						i, len(got[i]), len(tt.want[i]))
+					continue
+				}
+				for j := 0; j < len(got[i]); j++ {
+					if got[i][j] != tt.want[i][j] {
+						t.Errorf("shard %d matcher %d: got %s, want %s",
+							i, j, got[i][j], tt.want[i][j])
+					}
+				}
+			}
+		})
+	}
+}