How to reuse a selenium browser session

Question

I'm trying to access an existing selenium browser session from a separate python process. I'm able to get this working within the same python script, but when I break the reuse logic out to a separate script, it fails with the error message:

Traceback (most recent call last):
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 1318, in do_open
    encode_chunked=req.has_header('Transfer-encoding'))
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1239, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1285, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1234, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1026, in _send_output
    self.send(msg)
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 964, in send
    self.connect()
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 936, in connect
    (self.host,self.port), self.timeout, self.source_address)
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socket.py", line 722, in create_connection
    raise err
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socket.py", line 713, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 61] Connection refused

Here's the code that attempts to access the existing session from a separate script (this is the code that generates the error). Right now I'm updating the session_id and executor values each time manually:

""" module docstring """
import time
from selenium import webdriver

def main():
  """ reuse window in different scripts """
  # driver = webdriver.Chrome()
  session_id = '7b10acc2c99d90a68fecb71e5e481c0f'
  # executor_url = 'http://127.0.0.1:9515'
  executor_url = 'http://127.0.0.1:54467'

  print(session_id)
  print(executor_url)

  driver2 = webdriver.Remote(command_executor=executor_url,
                             desired_capabilities={})

  print('driver instance created')
  driver2.session_id = session_id
  print(driver2.current_url)
  driver2.get('http://www.yahoo.com')

  time.sleep(10)

if __name__ == '__main__':
  main()

This is the code that sets up the initial browser session:

""" module docstring """
import time
from selenium import webdriver

def main():
  """ reuse window in different scripts """
  driver = webdriver.Chrome()
  executor_url = driver.command_executor._url # pylint: disable=W0212
  session_id = driver.session_id
  driver.get("http://tarunlalwani.com")

  print(session_id)
  print(executor_url)

  time.sleep(300)

if __name__ == '__main__':
  main()

Here's the script that successfully alters the existing browser window, however this is from within the same python script:

""" module docstring """
import time
from selenium import webdriver

def main():
  """ reuse window in same script """
  driver = webdriver.Chrome()
  executor_url = driver.command_executor._url # pylint: disable=W0212
  session_id = driver.session_id
  driver.get("http://tarunlalwani.com")

  print(session_id)
  print(executor_url)

  driver2 = webdriver.Remote(command_executor=executor_url,
                             desired_capabilities={})
  driver2.session_id = session_id
  print(driver2.current_url)
  driver2.get('http://www.yahoo.com')

  time.sleep(300)

if __name__ == '__main__':
  main()

Answer 1

If you want the ultimate performance, you can make Selenium as an HTTP server to receive commands. Example:

# Created by [email protected] at 2022/1/29 11:58

import threading

import flask
import requests
import selenium.webdriver

app = flask.Flask(__name__)


@app.post("/")
def home():
    return str(driver.execute_script(flask.request.data.decode()))


threading.Thread(target=lambda: app.run(host="127.0.0.1", port=5000)).start()
driver = selenium.webdriver.Chrome()

print("1+1=", requests.post("http://localhost:5000", "return 1+1").text)
print("userAgent=", requests.post("http://localhost:5000", "return navigator.userAgent").text)

Answer 2

Here is an example using a one file solution, though it would work in a two file solution as well.

from selenium import webdriver
from selenium.webdriver.chrome.options import Options
from multiprocessing import Process
import time

# The main process calls this function to create the driver instance.
def createDriverInstance():
    options = Options()
    options.add_argument('--disable-infobars')
    driver = webdriver.Chrome(chrome_options=options, port=9515)
    return driver

# Called by the second process only.
def secondProcess(executor_url, session_id):
    options = Options()
    options.add_argument("--disable-infobars")
    options.add_argument("--enable-file-cookies")
    capabilities = options.to_capabilities()
    same_driver = webdriver.Remote(command_executor=executor_url, desired_capabilities=capabilities)
    same_driver.close()
    same_driver.session_id = session_id
    same_driver.get("https://www.wikipedia.org")
    time.sleep(4)
    same_driver.quit()

if __name__ == '__main__':
    driver = createDriverInstance()
    driver.get("https://google.com")
    time.sleep(2)

    # Pass the driver session and command_executor to the second process.
    p = Process(target=secondProcess, args=(driver.command_executor._url,driver.session_id))
    p.start()