Download file through Google Chrome in headless mode

问题

I\'m do me code in Cromedrive in \'normal\' mode and works fine. When I change to headless mode it don\'t download the file. I already try the code I found alround internet, but didn\'t work.

chrome_options = Options()
chrome_options.add_argument(\"--headless\")
self.driver = webdriver.Chrome(chrome_options=chrome_options, executable_path=r\'{}/chromedriver\'.format(os.getcwd()))
self.driver.set_window_size(1024, 768)
self.driver.command_executor._commands[\"send_command\"] = (\"POST\", \'/session/$sessionId/chromium/send_command\')

params = {\'cmd\': \'Page.setDownloadBehavior\', \'params\': {\'behavior\': \'allow\', \'downloadPath\': os.getcwd()}}
self.driver.execute(\"send_command\", params)

Anyone have any idea about how solve this problem? PS: I don\'t need to use Chomedrive necessarily. If it works in another drive it\'s fine for me.

回答1:

First the solution

Minimum Prerequisites:

• Selenium client version: Selenium v3.141.59
• Chrome version: Chrome v77.0
• ChromeDriver version: ChromeDriver v77.0

To download the file clicking on the element with text as Download Data within this website you can use the following solution:

• Code Block:

  from selenium import webdriver
  from selenium.webdriver.common.by import By
  from selenium.webdriver.support.ui import WebDriverWait
  from selenium.webdriver.support import expected_conditions as EC
  from selenium.webdriver.chrome.options import Options
  
  options = Options()
  options.add_argument("--headless")
  options.add_argument("--window-size=1920,1080")
  options.add_experimental_option("excludeSwitches", ["enable-automation"])
  options.add_experimental_option('useAutomationExtension', False)
  driver = webdriver.Chrome(chrome_options=options, executable_path=r'C:\Utility\BrowserDrivers\chromedriver.exe', service_args=["--log-path=./Logs/DubiousDan.log"])
  print ("Headless Chrome Initialized")
  params = {'behavior': 'allow', 'downloadPath': r'C:\Users\Debanjan.B\Downloads'}
  driver.execute_cdp_cmd('Page.setDownloadBehavior', params)
  driver.get("https://www.mockaroo.com/")
  driver.execute_script("scroll(0, 250)"); 
  WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR, "button#download"))).click()
  print ("Download button clicked")
  #driver.quit()
  

• Console Output:

  Headless Chrome Initialized
  Download button clicked
  

• File Downloading snapshot:

---

Details

Downloading files through Headless Chromium was one of the most sought functionality since Headless Chrome was introduced.

Since then there were different work-arounds published by different contributors and some of them are:

• Downloading with chrome headless and selenium
• Python equivalent of a given wget command

Now the, the good news is Chromium team have officially announced the arrival of the functionality Downloading file through Headless Chromium.

---

In the discussion Headless mode doesn't save file downloads @eseckler mentioned:

Downloads in headless work a little differently. There's the Page.setDownloadBehavior devtools command to set a download folder. We're working on a way to use DevTools network interception to stream the downloaded file via DevTools as well.

A detailed discussion can be found at Issue 696481: Headless mode doesn't save file downloads

Finally, @bugdroid revision seems to have nailed the issue for us.

---

[ChromeDriver] Added support for headless mode to download files

Previously, Chromedriver running in headless mode would not properly download files due to the fact it sparsely parses the preference file given to it. Engineers from the headless chrome team recommended using DevTools's "Page.setDownloadBehavior" to fix this. This changelist implements this fix. Downloaded files default to the current directory and can be set using download_dir when instantiating a chromedriver instance. Also added tests to ensure proper download functionality.

Here is the revision and commit

From ChromeDriver v77.0.3865.40 (2019-08-20) release notes:

Resolved issue 2454: Headless mode doesn't save file downloads [Pri-2]

---

Solution

• Update ChromeDriver to latest ChromeDriver v77.0 level.
• Update Chrome to Chrome Version 77.0 level. (as per ChromeDriver v76.0 release notes)

• Note: Chrome v77.0 is yet to be GAed/pushed for release so till then you can download and install a development build and test either from:

  • Chrome Canary
  • Latest build from the Dev Channel

---

Outro

However Mac OSX users have a wait for their pie as On Chromedriver, headless chrome crashes after sending Page.setDownloadBehavior on MacOSX.

回答2:

I don't think you should be using the browser for downloading content, leave it to Chrome developers/testers.

I believe you should rather get href attribute of the element you want to download and obtain it using requests library

If your site requires authentication you could fetch cookies from the browser instance and pass them to requests.Session.

来源：https://stackoverflow.com/questions/57599776/download-file-through-google-chrome-in-headless-mode