fix: adjust some code structure to satisfy linter

internal/cmd/cli.go

@@ -22,14 +22,14 @@ type AppSettings struct {
 
 //nolint:lll // ignore line length
 type CLI struct {
-	ServerAddress     string `name:"listen-address" env:"GEOIP_LISTEN_ADDRESS" help:"Address to use for the api server" default:"${default_address}"`
-	DataFile          string `name:"data-file" env:"GEOIP_DATA_FILE" help:"path to data file" default:"${default_file_path}"`
-	DataURL           string `name:"data-url" env:"GEOIP_DATA_URL" help:"url to data file"`
-	CacheTTL          string `name:"cache-ttl" env:"GEOIP_CACHE_TTL" help:"ttl for response cache" default:"${default_cache_ttl}"`
-	ReadHeaderTimeout string `name:"read-header-timeout" env:"GEOIP_READ_HEADER_TIMEOUT" help:"timeout for reading http header" default:"${default_read_header_timeout}"`
-	EnableExporter    bool   `name:"enable-exporter" env:"GEOIP_ENABLE_EXPORTER" help:"enable prometheus exporter" default:"${default_enable_exporter}"`
-	ExporterAddress   string `name:"exporter-address" env:"GEOIP_EXPORTER_ADDRESS" help:"Address to use for the prometheus metrics server" default:"${default_exporter_address}"`
-	ExporterInterval  string `name:"exporter-interval" env:"GEOIP_EXPORTER_INTERVAL" help:"Interval to scrape the new metrics data" default:"${default_exporter_interval}"`
+	ServerAddress     string `name:"listen-address"      env:"GEOIP_LISTEN_ADDRESS"      help:"Address to use for the api server"                default:"${default_address}"`
+	DataFile          string `name:"data-file"           env:"GEOIP_DATA_FILE"           help:"path to data file"                                default:"${default_file_path}"`
+	DataURL           string `name:"data-url"            env:"GEOIP_DATA_URL"            help:"url to data file"`
+	CacheTTL          string `name:"cache-ttl"           env:"GEOIP_CACHE_TTL"           help:"ttl for response cache"                           default:"${default_cache_ttl}"`
+	ReadHeaderTimeout string `name:"read-header-timeout" env:"GEOIP_READ_HEADER_TIMEOUT" help:"timeout for reading http header"                  default:"${default_read_header_timeout}"`
+	EnableExporter    bool   `name:"enable-exporter"     env:"GEOIP_ENABLE_EXPORTER"     help:"enable prometheus exporter"                       default:"${default_enable_exporter}"`
+	ExporterAddress   string `name:"exporter-address"    env:"GEOIP_EXPORTER_ADDRESS"    help:"Address to use for the prometheus metrics server" default:"${default_exporter_address}"`
+	ExporterInterval  string `name:"exporter-interval"   env:"GEOIP_EXPORTER_INTERVAL"   help:"Interval to scrape the new metrics data"          default:"${default_exporter_interval}"`
 }
 
 func (c *CLI) Parse() (*AppSettings, error) {

internal/downloader/downloader.go

@@ -40,7 +40,10 @@ func (c *Context) Download() error {
 		}
 		return err
 	}
-	defer resp.Close()
+	if err = resp.Close(); err != nil {
+		return err
+	}
+
 	if resp.StatusCode == http.StatusNotFound {
 		return ErrInvalidURL
 	}
@@ -50,19 +53,19 @@ func (c *Context) Download() error {
 	if resp.StatusCode != http.StatusOK {
 		return errors.New(resp.RawResponse.Status)
 	}
-	resp.Close()
 
 	resp, err = req.Get(c.Link, nil)
 	if err != nil {
 		return err
 	}
+	defer resp.Close()
 
 	var filesize int64
 	if resp.RawResponse.ContentLength > -1 {
 		filesize = resp.RawResponse.ContentLength
 	}
 
-	destFile, err := os.OpenFile(c.Filename, os.O_CREATE|os.O_WRONLY, 0644)
+	destFile, err := os.OpenFile(c.Filename, os.O_CREATE|os.O_WRONLY, 0600)
 	if err != nil {
 		return err
 	}

internal/downloader/downloader_test.go

@@ -58,7 +58,10 @@ func TestDownload(t *testing.T) {
 
 	t.Run("CertificateError", func(t *testing.T) {
 		// This test assumes a self-signed certificate or similar issue. This is hard to simulate in a unit test.
-		ctx := downloader.NewContext("test_cert_error.txt", "https://self-signed.badssl.com/") // Example URL that can be used
+		ctx := downloader.NewContext(
+			"test_cert_error.txt",
+			"https://self-signed.badssl.com/", // Example URL that can be used
+		)
 
 		if err := ctx.Download(); err == nil || err.Error() != "certificate from unknown authority" {
 			t.Errorf("expected certificate from unknown authority error, got %v", err)

internal/exporter/metrics.go

@@ -1,7 +1,7 @@
 package exporter
 
 import (
-	"log"
+	"log/slog"
 
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -95,7 +95,7 @@ func (m *Metrics) collectCurrentlyCachedMetric() {
 func (m *Metrics) collectDatabaseTimestampMetric() {
 	timestamp, err := m.exporter.database.Timestamp()
 	if err != nil {
-		log.Printf("failed to read file timestamp: %v", err)
+		slog.Warn("failed to read file timestamp", "error", err)
 		return
 	}