more optimizations

settings/get_settings.go

@@ -2,32 +2,51 @@ package settings
 
 import (
 	"dns_service/utils"
+	"fmt"
 	"os"
 	"strconv"
 )
 
 func GetSettings() (map[string]any, error) {
-	settings := make(map[string]any)
-	data, e := os.ReadFile(os.Getenv("DNSMASQ_CONFIG"))
-	if e != nil {
-		return settings, e
+	configPath := os.Getenv("DNSMASQ_CONFIG")
+	if configPath == "" {
+		return nil, fmt.Errorf("DNSMASQ_CONFIG environment variable not set")
 	}
+
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read config file at %s: %w", configPath, err)
+	}
+
 	dnsmasqSettings := utils.DecodeSettings(string(data), "\n", "=")
-	if dnsmasqSettings["cache-size"] != "" {
-		cache_size, _ := strconv.ParseInt(dnsmasqSettings["cache-size"], 10, 64)
-		settings["cache_size"] = cache_size
+	settings := make(map[string]any)
+
+	// Parse cache size
+	if cacheSizeStr, ok := dnsmasqSettings["cache-size"]; ok && cacheSizeStr != "" {
+		cacheSize, err := strconv.ParseInt(cacheSizeStr, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse cache-size '%s': %w", cacheSizeStr, err)
+		}
+		settings["cache_size"] = cacheSize
 	}
-	data, e = os.ReadFile(dnsmasqSettings["resolv-file"])
-	if e != nil {
-		return settings, e
+
+	// Read and parse resolv file
+	if resolvFile, ok := dnsmasqSettings["resolv-file"]; ok {
+		data, err := os.ReadFile(resolvFile)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read resolv-file at %s: %w", resolvFile, err)
+		}
+		settings["resolv"] = utils.DecodeResolvs(string(data))
 	}
-	resolvSettings := utils.DecodeResolvs(string(data))
-	settings["resolv"] = resolvSettings
-	data, e = os.ReadFile(dnsmasqSettings["addn-hosts"])
-	if e != nil {
-		return settings, e
+
+	// Read and parse hosts file
+	if hostsFile, ok := dnsmasqSettings["addn-hosts"]; ok {
+		data, err := os.ReadFile(hostsFile)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read addn-hosts file at %s: %w", hostsFile, err)
+		}
+		settings["hosts"] = utils.DecodeHosts(string(data))
 	}
-	hosts := utils.DecodeHosts(string(data))
-	settings["hosts"] = hosts
+
 	return settings, nil
 }

settings/set_settings.go

@@ -7,51 +7,86 @@ import (
 	"strings"
 )
 
-func SetSettings(new_settings map[string]any, old_settings map[string]any) (map[string]any, error) {
-	data, err := os.ReadFile(os.Getenv("DNSMASQ_CONFIG"))
+// Helper to write file content
+func writeFile(path, content string) error {
+	return os.WriteFile(path, []byte(content), 0644)
+}
+
+func SetSettings(new_settings map[string]any) (map[string]any, error) {
+	// 1. Get config path and read the main dnsmasq configuration
+	configPath := os.Getenv("DNSMASQ_CONFIG")
+	if configPath == "" {
+		return nil, fmt.Errorf("DNSMASQ_CONFIG environment variable not set")
+	}
+
+	data, err := os.ReadFile(configPath)
 	if err != nil {
-		return old_settings, err
+		return nil, fmt.Errorf("failed to read config file at %s: %w", configPath, err)
 	}
-	new_data := strings.Replace(
-		string(data),
-		"cache-size="+fmt.Sprintf("%v", old_settings["cache_size"]),
-		"cache-size="+fmt.Sprintf("%v", new_settings["cache_size"]),
-		1,
-	)
-	err = os.WriteFile(os.Getenv("DNSMASQ_CONFIG"), []byte(new_data), 0644)
-	if err != nil {
-		return old_settings, err
-	}
-	var resolvs string
-	new_resolvs := new_settings["resolv"].([]any)
-	for i := range new_resolvs {
-		resolvs += "nameserver " + new_resolvs[i].(string) + "\n"
-	}
-	var hosts string
-	new_hosts := new_settings["hosts"].(map[string]any)
-	for key, value := range new_hosts {
-		hosts += key
-		switch value.(type) {
-		case []any:
-			arrvalue := value.([]any)
-			for i := range arrvalue {
-				hosts += " " + arrvalue[i].(string)
+	dnsmasqSettings := utils.DecodeSettings(string(data), "\n", "=")
+
+	// 2. Update cache-size in the main config file
+	if newCacheSize, ok := new_settings["cache_size"]; ok {
+		oldCacheSize, oldOk := dnsmasqSettings["cache-size"]
+		// Replace the line if it exists, otherwise dnsmasq uses a default
+		if oldOk {
+			newConfigContent := strings.Replace(
+				string(data),
+				"cache-size="+oldCacheSize,
+				"cache-size="+fmt.Sprintf("%v", newCacheSize),
+				1,
+			)
+			if err := writeFile(configPath, newConfigContent); err != nil {
+				return nil, fmt.Errorf("failed to write updated config to %s: %w", configPath, err)
 			}
-			hosts += "\n"
-			break
-		case string:
-			hosts += " " + value.(string) + "\n"
 		}
 	}
-	fmt.Println(resolvs, hosts)
-	err = os.WriteFile("/etc/dnsmasq.conf.d/resolv.conf", []byte(resolvs), 0644)
-	if err != nil {
-		return old_settings, err
+
+	// 3. Update the resolv file
+	if newResolvs, ok := new_settings["resolv"].([]any); ok {
+		resolvFile, ok := dnsmasqSettings["resolv-file"]
+		if !ok {
+			return nil, fmt.Errorf("resolv-file path not found in dnsmasq config")
+		}
+		var b strings.Builder
+		for _, v := range newResolvs {
+			if s, ok := v.(string); ok {
+				fmt.Fprintf(&b, "nameserver %s\n", s)
+			}
+		}
+		if err := writeFile(resolvFile, b.String()); err != nil {
+			return nil, fmt.Errorf("failed to write to resolv file %s: %w", resolvFile, err)
+		}
 	}
-	err = os.WriteFile("/etc/dnsmasq.conf.d/hosts", []byte(hosts), 0644)
-	if err != nil {
-		return old_settings, err
+
+	// 4. Update the hosts file
+	if newHosts, ok := new_settings["hosts"].(map[string]any); ok {
+		hostsFile, ok := dnsmasqSettings["addn-hosts"]
+		if !ok {
+			return nil, fmt.Errorf("addn-hosts path not found in dnsmasq config")
+		}
+		var b strings.Builder
+		for key, value := range newHosts {
+			b.WriteString(key)
+			switch v := value.(type) {
+			case []any:
+				for _, ip := range v {
+					fmt.Fprintf(&b, " %s", ip)
+				}
+				b.WriteString("\n")
+			case string:
+				fmt.Fprintf(&b, " %s\n", v)
+			}
+		}
+		if err := writeFile(hostsFile, b.String()); err != nil {
+			return nil, fmt.Errorf("failed to write to hosts file %s: %w", hostsFile, err)
+		}
 	}
-	utils.RestartDnsmasq()
+
+	// 5. Restart dnsmasq to apply changes
+	if err := utils.RestartDnsmasq(); err != nil {
+		return nil, fmt.Errorf("failed to restart dnsmasq: %w", err)
+	}
+
 	return new_settings, nil
 }