Bug description
There seems to be an issue with the Selenium setup. The ~/.cache directory in the Docker image does not belong to the superset user but instead belongs to the root user. When starting trying to start a headless browser, a permission denied error seems to cause the webdriver to fail:
Screenshots/recordings
Superset version
5.0.0
Python version
3.11
Node version
I don't know
Browser
Not applicable
Additional context
[2025-08-05 13:26:00,605: WARNING/ForkPoolWorker-4] Cache folder (/app/superset_home/.cache/selenium) cannot be created: Permission denied (os error 13)
[2025-08-05 13:26:00,606: WARNING/ForkPoolWorker-4] Cache folder (/app/superset_home/.cache/selenium) cannot be created: Permission denied (os error 13)
[2025-08-05 13:26:00,606: WARNING/ForkPoolWorker-4] The geckodriver version (0.34.0) detected in PATH at /usr/bin/geckodriver might not be compatible with the detected firefox version (128.13.0); currently, geckodriver 0.36.0 is recommended for firefox 128.*, so it
is advised to delete the driver in PATH and retry
[2025-08-05 13:28:10,828: WARNING/ForkPoolWorker-4] SupersetError(message='[Errno 111] Connection refused', error_type=<SupersetErrorType.REPORT_NOTIFICATION_ERROR: 'REPORT_NOTIFICATION_ERROR'>, level=<ErrorLevel.ERROR: 'error'>, extra=None)
[2025-08-05 13:28:10,835: ERROR/ForkPoolWorker-4] A downstream exception occurred while generating a report: fcd05b88-6472-4e9d-91ec-375af5882fdb. Failed taking a screenshot HTTPConnectionPool(host='localhost', port=34831): Read timed out. (read timeout=120)
Traceback (most recent call last):
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 467, in _make_request
six.raise_from(e, None)
File "<string>", line 3, in raise_from
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 462, in _make_request
httplib_response = conn.getresponse()
File "/usr/local/lib/python3.10/http/client.py", line 1375, in getresponse
response.begin()
File "/usr/local/lib/python3.10/http/client.py", line 318, in begin
version, status, reason = self._read_status()
File "/usr/local/lib/python3.10/http/client.py", line 279, in _read_status
line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
File "/usr/local/lib/python3.10/socket.py", line 717, in readinto
return self._sock.recv_into(b)
TimeoutError: timed out
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/app/superset/commands/report/execute.py", line 357, in _get_screenshots
if imge := screenshot.get_screenshot(user=user):
File "/app/superset/utils/screenshots.py", line 176, in get_screenshot
self.screenshot = driver.get_screenshot(self.url, self.element, user)
File "/app/superset/utils/webdriver.py", line 387, in get_screenshot
driver = self.auth(user)
File "/app/superset/utils/webdriver.py", line 311, in auth
driver = self.create()
File "/app/superset/utils/webdriver.py", line 308, in create
return driver_class(**kwargs)
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/firefox/webdriver.py", line 71, in __init__
super().__init__(command_executor=executor, options=options)
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 241, in __init__
self.start_session(capabilities)
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 329, in start_session
response = self.execute(Command.NEW_SESSION, caps)["value"]
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 382, in execute
response = self.command_executor.execute(driver_command, params)
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/remote/remote_connection.py", line 404, in execute
return self._request(command_info[0], url, body=data)
File "/app/.venv/lib/python3.10/site-packages/selenium/webdriver/remote/remote_connection.py", line 428, in _request
response = self._conn.request(method, url, body=body, headers=headers, timeout=self._client_config.timeout)
File "/app/.venv/lib/python3.10/site-packages/urllib3/request.py", line 81, in request
return self.request_encode_body(
File "/app/.venv/lib/python3.10/site-packages/urllib3/request.py", line 173, in request_encode_body
return self.urlopen(method, url, **extra_kw)
File "/app/.venv/lib/python3.10/site-packages/urllib3/poolmanager.py", line 376, in urlopen
response = conn.urlopen(method, u.request_uri, **kw)
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 799, in urlopen
retries = retries.increment(
File "/app/.venv/lib/python3.10/site-packages/urllib3/util/retry.py", line 550, in increment
raise six.reraise(type(error), error, _stacktrace)
File "/app/.venv/lib/python3.10/site-packages/urllib3/packages/six.py", line 770, in reraise
raise value
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 715, in urlopen
httplib_response = self._make_request(
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 469, in _make_request
self._raise_timeout(err=e, url=url, timeout_value=read_timeout)
File "/app/.venv/lib/python3.10/site-packages/urllib3/connectionpool.py", line 358, in _raise_timeout
raise ReadTimeoutError(
urllib3.exceptions.ReadTimeoutError: HTTPConnectionPool(host='localhost', port=34831): Read timed out. (read timeout=120)
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/app/superset/tasks/scheduler.py", line 99, in execute
).run()
File "/app/superset/utils/decorators.py", line 266, in wrapped
return on_error(ex)
File "/app/superset/utils/decorators.py", line 236, in on_error
raise ex
File "/app/superset/utils/decorators.py", line 259, in wrapped
result = func(*args, **kwargs)
File "/app/superset/commands/report/execute.py", line 896, in run
).run()
File "/app/superset/utils/decorators.py", line 266, in wrapped
return on_error(ex)
File "/app/superset/utils/decorators.py", line 236, in on_error
raise ex
File "/app/superset/utils/decorators.py", line 259, in wrapped
result = func(*args, **kwargs)
File "/app/superset/commands/report/execute.py", line 858, in run
).next()
File "/app/superset/commands/report/execute.py", line 726, in next
self.send()
File "/app/superset/commands/report/execute.py", line 624, in send
notification_content = self._get_notification_content()
File "/app/superset/commands/report/execute.py", line 509, in _get_notification_content
pdf_data = self._get_pdf()
File "/app/superset/commands/report/execute.py", line 375, in _get_pdf
screenshots = self._get_screenshots()
File "/app/superset/commands/report/execute.py", line 363, in _get_screenshots
raise ReportScheduleScreenshotFailedError(
superset.commands.report.exceptions.ReportScheduleScreenshotFailedError: Failed taking a screenshot HTTPConnectionPool(host='localhost', port=34831): Read timed out. (read timeout=120)
Checklist
- [x] I have searched Superset docs and Slack and didn't find a solution to my problem.
- [x] I have searched the GitHub issue tracker and didn't find a similar bug report.
- [x] I have checked Superset's logs for errors and if I found a relevant Python stacktrace, I included it here as text in the "additional context" section.
Comment From: dosubot[bot]
This is a known class of issue with Docker-based Superset deployments: if the ~/.cache directory (or its subdirectories) is owned by root instead of the superset user, Selenium can't write to it, causing "Permission denied" errors and screenshot/report failures. This isn't handled in Superset's Python code but is a result of Docker image setup and file ownership during build or container startup. The default 5.0.0 image doesn't explicitly fix this, so the bug can appear when running as the superset user example.
To work around this, you can add a command to your Dockerfile or entrypoint to fix directory ownership before starting Superset, for example:
USER root
RUN chown -R superset:superset /app/superset_home/.cache || true
USER superset
or, in your entrypoint script:
chown -R superset:superset /app/superset_home/.cache || true
You also have a geckodriver/Firefox version mismatch: geckodriver 0.36.0 is recommended for Firefox 128.*. Download and install the correct geckodriver version in your Dockerfile to avoid further Selenium failures example.
If you want to avoid these manual steps, using the -dev image (which includes browsers and drivers with correct permissions) is a common workaround example.
Let me know if you need a full Dockerfile example or more details on aligning geckodriver and Firefox versions.
To reply, just mention @dosu.
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Comment From: rusackas
The bot is correct! Closing, but happy to move it to a Q&A thread if there's more to address.