Screenshot a list of URLs using Google Chrome API

main.go

package main

import (
	"bufio"
	"context"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"strings"
	"time"

	"github.com/mafredri/cdp"
	"github.com/mafredri/cdp/devtool"
	"github.com/mafredri/cdp/protocol/page"
	"github.com/mafredri/cdp/protocol/security"
	"github.com/mafredri/cdp/rpcc"
)

var filename string

func init() {

	flag.StringVar(&filename, "f", "", `Specify a filename with a list of URLs.`)

	flag.Parse()

	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, "~ govisu")
		flag.PrintDefaults()
	}

	if len(filename) == 0 {
		flag.Usage()
		log.Fatal()
	}
}

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Minute)
	defer cancel()

	devt := devtool.New("http://127.1:9222")
	pt, err := devt.Get(ctx, devtool.Page)
	if err != nil {
		pt, err = devt.Create(ctx)
		if err != nil {
			log.Println(`💁  Manually run a Google Chrome daemon.
On MacOS 🍏  : /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222 --no-first-run --no-default-browser-check --user-data-dir=$(mktemp -d -t 'chrome-remote_data_dir') --headless &`)
			log.Fatal(err)
		}
	}
	security.NewSetIgnoreCertificateErrorsArgs(true)
	conn, err := rpcc.DialContext(ctx, pt.WebSocketDebuggerURL)
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close()

	c := cdp.NewClient(conn)

	domContent, err := c.Page.LoadEventFired(ctx)
	if err != nil {
		log.Fatal(err)
	}
	defer domContent.Close()

	if err = c.Page.Enable(ctx); err != nil {
		log.Fatal(err)
	}

	file, err := os.Open(filename)
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {

		navArgs := page.NewNavigateArgs(scanner.Text())
		_, err := c.Page.Navigate(ctx, navArgs)
		if err != nil {
			log.Fatal(err)
		}

		if _, err = domContent.Recv(); err != nil {
			log.Fatal(err)
		}

		screenshotName := strings.ReplaceAll(scanner.Text(), "/", "") + ".jpg"
		screenshotArgs := page.NewCaptureScreenshotArgs().
			SetFormat("jpeg").
			SetQuality(10)
		screenshot, err := c.Page.CaptureScreenshot(ctx, screenshotArgs)
		if err != nil {
			log.Fatal(err)
		}
		if err = ioutil.WriteFile(screenshotName, screenshot.Data, 0644); err != nil {
			log.Fatal(err)
		}

		fmt.Printf("Saved screenshot: %s\n", screenshotName)
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}
}