Can't run SeleniumBase with UC on Linux server by CRON

[JaKeRUS]

Greetings!

I have a problem with launching SeleniumBase Python script on the Linux server (Ubuntu 20.04) by crontab. With manually launching by SSH it works perfectly. Script fails from the start, it looks like this:

with SB(uc=True, xvfb=True) as sb:
url = "https://www.google.com/"
sb.uc_open_with_disconnect(url, 5)

Got this error in log file:

2024-11-02 13:25:03,024 - ERROR -   File "/var/www/www-root/data/www/somesite.com/pscripts/sb_parser.py", line 91, in <module>
2024-11-02 13:25:03,025 - ERROR - with SB(uc=True, xvfb=True) as sb:
2024-11-02 13:25:03,025 - ERROR -   File "/usr/lib/python3.10/contextlib.py", line 135, in __enter__
2024-11-02 13:25:03,025 - ERROR - return next(self.gen)
2024-11-02 13:25:03,025 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/plugins/sb_manager.py", line 1215, in SB
2024-11-02 13:25:03,025 - ERROR - sb.setUp()
2024-11-02 13:25:03,025 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/fixtures/base_case.py", line 14977, in setUp
2024-11-02 13:25:03,028 - ERROR - self.driver = self.get_new_driver(
2024-11-02 13:25:03,029 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/fixtures/base_case.py", line 4094, in get_new_driver
2024-11-02 13:25:03,029 - ERROR - new_driver = browser_launcher.get_driver(
2024-11-02 13:25:03,029 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/core/browser_launcher.py", line 2695, in get_driver
2024-11-02 13:25:03,030 - ERROR - return get_local_driver(
2024-11-02 13:25:03,030 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/core/browser_launcher.py", line 4697, in get_local_driver
2024-11-02 13:25:03,031 - ERROR - driver = undetected.Chrome(
2024-11-02 13:25:03,031 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/undetected/__init__.py", line 314, in __init__
2024-11-02 13:25:03,031 - ERROR - super().__init__(options=options, service=service_)
2024-11-02 13:25:03,031 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/chrome/webdriver.py", line 45, in __init__
2024-11-02 13:25:03,031 - ERROR - super().__init__(
2024-11-02 13:25:03,032 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/chromium/webdriver.py", line 66, in __init__
2024-11-02 13:25:03,032 - ERROR - super().__init__(command_executor=executor, options=options)
2024-11-02 13:25:03,032 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 212, in __init__
2024-11-02 13:25:03,032 - ERROR - self.start_session(capabilities)
2024-11-02 13:25:03,032 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/seleniumbase/undetected/__init__.py", line 481, in start_session
2024-11-02 13:25:03,032 - ERROR - super().start_session(capabilities)
2024-11-02 13:25:03,032 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 299, in start_session
2024-11-02 13:25:03,032 - ERROR - response = self.execute(Command.NEW_SESSION, caps)["value"]
2024-11-02 13:25:03,033 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 354, in execute
2024-11-02 13:25:03,033 - ERROR - self.error_handler.check_response(response)
2024-11-02 13:25:03,033 - ERROR -   File "/var/www/www-root/data/www/somesite.com/venv/lib/python3.10/site-packages/selenium/webdriver/remote/errorhandler.py", line 229, in check_response
2024-11-02 13:25:03,033 - ERROR - raise exception_class(message, screen, stacktrace)
2024-11-02 13:25:03,033 - ERROR - selenium.common.exceptions
2024-11-02 13:25:03,033 - ERROR - .
2024-11-02 13:25:03,033 - ERROR - WebDriverException
2024-11-02 13:25:03,033 - ERROR - :
2024-11-02 13:25:03,033 - ERROR - Message: unknown error: cannot connect to chrome at 127.0.0.1:9515
from chrome not reachable
Stacktrace:
#0 0x557427607f83 <unknown>
#1 0x5574272c0b2b <unknown>
#2 0x5574272aaada <unknown>
#3 0x5574272fd3d8 <unknown>
#4 0x5574272f4168 <unknown>
#5 0x55742734580c <unknown>
#6 0x557427339e53 <unknown>
#7 0x557427301dd4 <unknown>
#8 0x5574273031de <unknown>
#9 0x5574275cc531 <unknown>
#10 0x5574275d0455 <unknown>
#11 0x5574275b8f55 <unknown>
#12 0x5574275d10ef <unknown>
#13 0x55742759c99f <unknown>
#14 0x5574275f5008 <unknown>
#15 0x5574275f51d7 <unknown>
#16 0x557427607124 <unknown>
#17 0x7fb068887ac3 <unknown>```

[mdmintz]

See https://github.com/search?q=repo%3Aseleniumbase%2FSeleniumBase+unknown+error%3A+cannot+connect+to+chrome&type=discussions
Could be caused by various issues, such missing permissions, not using “google-chrome-stable” or “google-chrome” on Linux, or improper multithreading.

[JaKeRUS]

What kind of permissions script must have? It got usual permissions like the others scripts on the server and all priveleges (777), so whats the matter? I have already insalled google-chrome-stable and google-chrome, so if I hadn't done this, manual start via the SSH wouldn't have worked, would it? And I dont use multithreading. Already tried to add something to select display by index like "export DISPLAY:0" in the bash script or cron commandline, so nothing happens, just an error. I read somewhere on the Internet that launching via CRON is not the same as via SSH, so maybe there is some solution regarding this?

[mdmintz]

If cron launching is different from SSH launching, then I would look into that. Same issue has been seen with regular Selenium, so it’s not specific to SeleniumBase, and so there’s not much I can do from my end.

[JaKeRUS]

It turned out to be very simple - you need to point your finger at the location of the browser google-chrome by binary_location = '/usr/bin/google-chrome'. Hmm, it looks like CRON can't automatically find the path to the browser and doesn't use any default paths to it (they are usually the same for Linux)