fix: redis plugin goroutine leak triggered by auto reload config mechanism (#11143)

plugins/inputs/redis/redis.go

@@ -37,7 +37,7 @@ type Redis struct {
 	Password string
 	tls.ClientConfig
 
-	Log telegraf.Logger
+	Log telegraf.Logger `toml:"-"`
 
 	clients   []Client
 	connected bool
@@ -47,6 +47,7 @@ type Client interface {
 	Do(returnType string, args ...interface{}) (interface{}, error)
 	Info() *redis.StringCmd
 	BaseTags() map[string]string
+	Close() error
 }
 
 type RedisClient struct {
@@ -192,6 +193,10 @@ func (r *RedisClient) BaseTags() map[string]string {
 	return tags
 }
 
+func (r *RedisClient) Close() error {
+	return r.client.Close()
+}
+
 var replicationSlaveMetricPrefix = regexp.MustCompile(`^slave\d+`)
 
 var Tracking = map[string]string{
@@ -697,3 +702,17 @@ func coerceType(value interface{}, typ reflect.Type) reflect.Value {
 	}
 	return reflect.ValueOf(value)
 }
+
+func (r *Redis) Start(telegraf.Accumulator) error {
+	return nil
+}
+
+//Stop close the client through ServiceInput interface Start/Stop methods impl.
+func (r *Redis) Stop() {
+	for _, c := range r.clients {
+		err := c.Close()
+		if err != nil {
+			r.Log.Errorf("error closing client: %v", err)
+		}
+	}
+}

plugins/inputs/redis/redis_test.go

@@ -29,6 +29,10 @@ func (t *testClient) Do(_ string, _ ...interface{}) (interface{}, error) {
 	return 2, nil
 }
 
+func (t *testClient) Close() error {
+	return nil
+}
+
 func TestRedisConnectIntegration(t *testing.T) {
 	if testing.Short() {
 		t.Skip("Skipping integration test in short mode")