Use log/slog package

Minimum Go version required: 1.21

Author: corny

.github/workflows/go.yaml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         platform: [ubuntu-22.04]
-        go-version: [1.21.x, 1.20.x]
+        go-version: [1.21.x, 1.x]
     runs-on: ${{ matrix.platform }}
     name: Linters (Static Analysis) for Go
     steps:
@@ -27,7 +27,7 @@ jobs:
     strategy:
       matrix:
         platform: [ubuntu-22.04]
-        go-version: [1.21.x, 1.20.x]
+        go-version: [1.21.x, 1.x]
     runs-on: ${{ matrix.platform }}
     name: integration tests
     env:

.github/workflows/schedule.yaml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         platform: [ubuntu-22.04]
-        go-version: [1.20.x]
+        go-version: [1.21.x]
     runs-on: ${{ matrix.platform }}
     name: integration tests
     env:

Makefile

@@ -1,4 +1,5 @@
 FILES_TO_FMT      ?= $(shell find . -path ./vendor -prune -o -name '*.go' -print)
+LOGLEVEL	?= debug
 
 ## help: Show makefile commands
 .PHONY: help
@@ -38,14 +39,14 @@ format:
 ## test-unit: Run all Youtube Go unit tests
 .PHONY: test-unit
 test-unit:
-	go test -v -cover ./...
+	LOGLEVEL=${LOGLEVEL} go test -v -cover ./...
 
 ## test-integration: Run all Youtube Go integration tests
 .PHONY: test-integration
 test-integration:
 	mkdir -p output
 	rm -f output/*
-	ARTIFACTS=output go test -race -covermode=atomic -coverprofile=coverage.out -tags=integration ./...
+	LOGLEVEL=${LOGLEVEL} ARTIFACTS=output go test -v -race -covermode=atomic -coverprofile=coverage.out -tags=integration ./...
 
 .PHONY: coverage.out
 coverage.out:

artifacts.go

@@ -1,7 +1,7 @@
 package youtube
 
 import (
-	"log"
+	"log/slog"
 	"os"
 	"path/filepath"
 )
@@ -13,15 +13,17 @@ func writeArtifact(name string, content []byte) {
 	// Ensure folder exists
 	err := os.MkdirAll(artifactsFolder, os.ModePerm)
 	if err != nil {
-		log.Printf("unable to create artifacts folder %s: %s", artifactsFolder, err)
+		slog.Error("unable to create artifacts folder", "path", artifactsFolder, "error", err)
 		return
 	}
 
 	path := filepath.Join(artifactsFolder, name)
 	err = os.WriteFile(path, content, 0600)
+
+	log := slog.With("path", path)
 	if err != nil {
-		log.Printf("unable to write artifact %s: %v", path, err)
+		log.Error("unable to write artifact", "error", err)
 	} else {
-		log.Println("artifact created:", path)
+		log.Debug("artifact created")
 	}
 }

client.go

@@ -7,12 +7,13 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"math/rand"
 	"net/http"
 	"net/url"
 	"strconv"
 	"sync/atomic"
+
+	"log/slog"
 )
 
 const (
@@ -32,9 +33,6 @@ var DefaultClient = AndroidClient
 
 // Client offers methods to download video metadata and video streams.
 type Client struct {
-	// Debug enables debugging output through log package
-	Debug bool
-
 	// HTTPClient can be used to set a custom HTTP client.
 	// If not set, http.DefaultClient will be used
 	HTTPClient *http.Client
@@ -484,10 +482,6 @@ func (c *Client) httpDo(req *http.Request) (*http.Response, error) {
 		client = http.DefaultClient
 	}
 
-	if c.Debug {
-		log.Println(req.Method, req.URL)
-	}
-
 	req.Header.Set("User-Agent", c.client.userAgent)
 	req.Header.Set("Origin", "https://youtube.com")
 	req.Header.Set("Sec-Fetch-Mode", "navigate")
@@ -505,8 +499,12 @@ func (c *Client) httpDo(req *http.Request) (*http.Response, error) {
 
 	res, err := client.Do(req)
 
-	if c.Debug && res != nil {
-		log.Println(res.Status)
+	log := slog.With("method", req.Method, "url", req.URL)
+
+	if err != nil {
+		log.Debug("HTTP request failed", "error", err)
+	} else {
+		log.Debug("HTTP request succeeded", "status", res.Status)
 	}
 
 	return res, err

client_test.go

@@ -10,15 +10,15 @@ import (
 	"golang.org/x/net/context"
 )
 
-var testClient = Client{Debug: true}
-var testWebClient = Client{Debug: true, client: &WebClient}
-
 const (
 	dwlURL    string = "https://www.youtube.com/watch?v=rFejpH_tAHM"
 	streamURL string = "https://www.youtube.com/watch?v=a9LDPn-MO4I"
 	errURL    string = "https://www.youtube.com/watch?v=I8oGsuQ"
 )
 
+var testClient = Client{}
+var testWebClient = Client{client: &WebClient}
+
 func TestParseVideo(t *testing.T) {
 	video, err := testClient.GetVideo(dwlURL)
 	assert.NoError(t, err)
@@ -162,7 +162,6 @@ func TestGetStream(t *testing.T) {
 
 	// Create testclient to enforce re-using of routines
 	testClient := Client{
-		Debug:       true,
 		MaxRoutines: 10,
 		ChunkSize:   int64(expectedSize) / 11,
 	}

cmd/youtubedr/downloader.go

@@ -4,7 +4,6 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
-	"log"
 	"net"
 	"net/http"
 	"net/url"
@@ -54,8 +53,10 @@ func getDownloader() *ytdl.Downloader {
 		}).DialContext,
 	}
 
+	youtube.SetLogLevel(logLevel)
+
 	if insecureSkipVerify {
-		log.Println("Skip server certificate verification")
+		youtube.Logger.Info("Skip server certificate verification")
 		httpTransport.TLSClientConfig = &tls.Config{
 			InsecureSkipVerify: true,
 		}
@@ -64,7 +65,6 @@ func getDownloader() *ytdl.Downloader {
 	downloader = &ytdl.Downloader{
 		OutputDir: outputDir,
 	}
-	downloader.Client.Debug = verbose
 	downloader.HTTPClient = &http.Client{Transport: httpTransport}
 
 	return downloader

cmd/youtubedr/root.go

@@ -2,8 +2,6 @@ package main
 
 import (
 	"fmt"
-	"io"
-	"log"
 	"os"
 
 	homedir "github.com/mitchellh/go-homedir"
@@ -12,8 +10,8 @@ import (
 )
 
 var (
-	cfgFile string
-	verbose bool
+	cfgFile  string
+	logLevel string
 )
 
 // rootCmd represents the base command when called without any subcommands
@@ -31,18 +29,13 @@ Use the HTTP_PROXY environment variable to set a HTTP or SOCSK5 proxy. The proxy
 
 func init() {
 	cobra.OnInitialize(initConfig)
-	cobra.OnInitialize(func() {
-		if !verbose {
-			log.SetOutput(io.Discard)
-		}
-	})
 
 	// Here you will define your flags and configuration settings.
 	// Cobra supports persistent flags, which, if defined here,
 	// will be global for your application.
 
 	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.youtubedr.yaml)")
-	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "Enable verbose output")
+	rootCmd.PersistentFlags().StringVar(&logLevel, "log-level", "info", "Set log level (error/warn/info/debug)")
 	rootCmd.PersistentFlags().BoolVar(&insecureSkipVerify, "insecure", false, "Skip TLS server certificate verification")
 }
 

decipher.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log"
 	"net/url"
 	"regexp"
 	"strconv"
@@ -76,17 +75,18 @@ func (c *Client) unThrottle(ctx context.Context, videoID string, urlString strin
 func (c *Client) decryptNParam(config playerConfig, query url.Values) (url.Values, error) {
 	// decrypt n-parameter
 	nSig := query.Get("v")
+	log := Logger.With("n", nSig)
+
 	if nSig != "" {
 		nDecoded, err := config.decodeNsig(nSig)
 		if err != nil {
 			return nil, fmt.Errorf("unable to decode nSig: %w", err)
 		}
 		query.Set("v", nDecoded)
+		log = log.With("decoded", nDecoded)
 	}
 
-	if c.Debug {
-		log.Printf("[nParam] n: %s; nDecoded: %s\nQuery: %v\n", nSig, query.Get("v"), query)
-	}
+	log.Debug("nParam")
 
 	return query, nil
 }

downloader/downloader.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -38,7 +37,12 @@ func (dl *Downloader) getOutputFile(v *youtube.Video, format *youtube.Format, ou
 
 // Download : Starting download video by arguments.
 func (dl *Downloader) Download(ctx context.Context, v *youtube.Video, format *youtube.Format, outputFile string) error {
-	dl.logf("Video '%s' - Quality '%s' - Codec '%s'", v.Title, format.QualityLabel, format.MimeType)
+	youtube.Logger.Info(
+		"Downloading video",
+		"id", v.ID,
+		"quality", format.Quality,
+		"mimeType", format.MimeType,
+	)
 	destFile, err := dl.getOutputFile(v, format, outputFile)
 	if err != nil {
 		return err
@@ -51,7 +55,6 @@ func (dl *Downloader) Download(ctx context.Context, v *youtube.Video, format *yo
 	}
 	defer out.Close()
 
-	dl.logf("Download to file=%s", destFile)
 	return dl.videoDLWorker(ctx, out, v, format)
 }
 
@@ -62,7 +65,15 @@ func (dl *Downloader) DownloadComposite(ctx context.Context, outputFile string,
 		return err1
 	}
 
-	dl.logf("Video '%s' - Quality '%s' - Video Codec '%s' - Audio Codec '%s'", v.Title, videoFormat.QualityLabel, videoFormat.MimeType, audioFormat.MimeType)
+	log := youtube.Logger.With("id", v.ID)
+
+	log.Info(
+		"Downloading composite video",
+		"videoQuality", videoFormat.QualityLabel,
+		"videoMimeType", videoFormat.MimeType,
+		"audioMimeType", audioFormat.MimeType,
+	)
+
 	destFile, err := dl.getOutputFile(v, videoFormat, outputFile)
 	if err != nil {
 		return err
@@ -83,13 +94,13 @@ func (dl *Downloader) DownloadComposite(ctx context.Context, outputFile string,
 	}
 	defer os.Remove(audioFile.Name())
 
-	dl.logf("Downloading video file...")
+	log.Debug("Downloading video file...")
 	err = dl.videoDLWorker(ctx, videoFile, v, videoFormat)
 	if err != nil {
 		return err
 	}
 
-	dl.logf("Downloading audio file...")
+	log.Debug("Downloading audio file...")
 	err = dl.videoDLWorker(ctx, audioFile, v, audioFormat)
 	if err != nil {
 		return err
@@ -106,7 +117,7 @@ func (dl *Downloader) DownloadComposite(ctx context.Context, outputFile string,
 	)
 	ffmpegVersionCmd.Stderr = os.Stderr
 	ffmpegVersionCmd.Stdout = os.Stdout
-	dl.logf("merging video and audio to %s", destFile)
+	log.Info("merging video and audio", "output", destFile)
 
 	return ffmpegVersionCmd.Run()
 }
@@ -184,9 +195,3 @@ func (dl *Downloader) videoDLWorker(ctx context.Context, out *os.File, video *yo
 	progress.Wait()
 	return nil
 }
-
-func (dl *Downloader) logf(format string, v ...interface{}) {
-	if dl.Debug {
-		log.Printf(format, v...)
-	}
-}