fix download with etag

internal/services/db_updater/downloader.go

@@ -1,6 +1,7 @@
 package db_updater
 
 import (
+	"fmt"
 	"github.com/go-resty/resty/v2"
 	"github.com/rs/zerolog/log"
 	"net/http"
@@ -12,11 +13,13 @@ import (
 func download(url string) bool {
 	log.Info().Str("url", url).Msg("Downloading DB")
 	filename := configs.GeoDbFolder + path.Base(url)
+	filenameEtag := filename + ".etag"
+
+	etag, _ := readFile(filenameEtag)
 
 	client := resty.New()
 	resp, err := client.R().
-		SetOutput(filename).
-		SetHeader("If-None-Match", readETag(filename)).
+		SetHeader("If-None-Match", etag).
 		Get(url)
 
 	if err != nil {
@@ -26,32 +29,35 @@ func download(url string) bool {
 		return false
 	}
 
-	if resp.StatusCode() == http.StatusOK {
-		writeETag(filename, resp.Header().Get("Etag"))
-	} else {
-		//log.Printf("No update needed: %v", resp.Status())
+	switch resp.StatusCode() {
+	case http.StatusNotModified:
+		fmt.Printf("No update needed: %v\n", resp.Status())
+		return true
+	case http.StatusOK:
+		_ = writeFileSByte(filename, resp.Body())
+		_ = writeFileString(filenameEtag, resp.Header().Get("Etag"))
+
+		return true
+	default:
 		return false
 	}
-
-	log.Info().
-		Str("filename", filename).
-		Msg("Downloaded DB")
-	return true
 }
 
-// readETag reads the ETag from the file
-func readETag(baseFile string) string {
-	data, err := os.ReadFile(baseFile + ".etag")
+func readFile(file string) (string, error) {
+	data, err := os.ReadFile(file)
 	if err != nil {
-		return ""
+		if os.IsNotExist(err) {
+			return "", nil
 		}
-	return string(data)
+		return "", err
+	}
+	return string(data), nil
 }
 
-// writeETag writes the ETag to the file
-func writeETag(baseFile, etag string) {
-	err := os.WriteFile(baseFile+".etag", []byte(etag), 0644)
-	if err != nil {
-		log.Err(err).Msg("Failed to write ETag")
+func writeFileString(file, content string) error {
+	return writeFileSByte(file, []byte(content))
 }
+
+func writeFileSByte(file string, content []byte) error {
+	return os.WriteFile(file, content, 0644)
 }