home: add stats qlog custom dir

internal/home/config.go

@@ -259,6 +259,9 @@ type tlsConfigSettings struct {
 }
 
 type queryLogConfig struct {
+	// DirPath is the custom directory for logs.
+	DirPath string `yaml:"dir_path"`
+
 	// Ignored is the list of host names, which should not be written to log.
 	// "." is considered to be the root domain.
 	Ignored []string `yaml:"ignored"`
@@ -278,6 +281,9 @@ type queryLogConfig struct {
 }
 
 type statsConfig struct {
+	// DirPath is the custom directory for statistics.
+	DirPath string `yaml:"dir_path"`
+
 	// Ignored is the list of host names, which should not be counted.
 	Ignored []string `yaml:"ignored"`
 

internal/home/dns.go

@@ -46,12 +46,15 @@ func onConfigModified() {
 // server and initializes it at last.  It also must not be called unless
 // [config] and [Context] are initialized.
 func initDNS() (err error) {
-	baseDir := Context.getDataDir()
-
 	anonymizer := config.anonymizer()
 
+	statsDir, querylogDir, err := checkStatsAndQuerylogDirs(&Context, config)
+	if err != nil {
+		return err
+	}
+
 	statsConf := stats.Config{
-		Filename:          filepath.Join(baseDir, "stats.db"),
+		Filename:          filepath.Join(statsDir, "stats.db"),
 		Limit:             config.Stats.Interval.Duration,
 		ConfigModified:    onConfigModified,
 		HTTPRegister:      httpRegister,
@@ -75,7 +78,7 @@ func initDNS() (err error) {
 		ConfigModified:    onConfigModified,
 		HTTPRegister:      httpRegister,
 		FindClient:        Context.clients.findMultiple,
-		BaseDir:           baseDir,
+		BaseDir:           querylogDir,
 		AnonymizeClientIP: config.DNS.AnonymizeClientIP,
 		RotationIvl:       config.QueryLog.Interval.Duration,
 		MemSize:           config.QueryLog.MemSize,
@@ -545,3 +548,49 @@ func (r safeSearchResolver) LookupIP(
 
 	return ips, nil
 }
+
+// checkStatsAndQuerylogDirs checks and returns directory paths to store
+// statistics and query log.
+func checkStatsAndQuerylogDirs(
+	ctx *homeContext,
+	conf *configuration,
+) (statsDir, querylogDir string, err error) {
+	baseDir := ctx.getDataDir()
+
+	statsDir = conf.Stats.DirPath
+	if statsDir == "" {
+		statsDir = baseDir
+	} else {
+		err = checkDir(statsDir)
+		if err != nil {
+			return "", "", fmt.Errorf("statistics: custom directory: %w", err)
+		}
+	}
+
+	querylogDir = conf.QueryLog.DirPath
+	if querylogDir == "" {
+		querylogDir = baseDir
+	} else {
+		err = checkDir(querylogDir)
+		if err != nil {
+			return "", "", fmt.Errorf("querylog: custom directory: %w", err)
+		}
+	}
+
+	return statsDir, querylogDir, nil
+}
+
+// checkDir checks if the path is a directory.
+func checkDir(path string) (err error) {
+	var fi os.FileInfo
+	if fi, err = os.Stat(path); err != nil {
+		// Don't wrap the error, since it's informative enough as is.
+		return err
+	}
+
+	if !fi.IsDir() {
+		return fmt.Errorf("%q is not a directory", path)
+	}
+
+	return nil
+}