GitLab service connection refused

[demonintherough]

Implementing plotly dash testing within the GitLab CI environment using services such as selenium/standalone-chrome causes a connection refused when running tests.

stages:
  - test

image: "python"

test:
  stage: test
  tags:
    - docker
  services:
    - selenium/standalone-chrome:latest
  script:
    # Set environmental variables
    - DEV_DASHBOARD_CFG='./app/config.json'
    - apt-get update -qy
    # Setup the application to run
    - apt-get install -y python-dev python-pip
    - pip install -r requirements.txt
    - cd app/
    - python3 -m pytest --junitxml=report.xml --log-cli-level DEBUG --webdriver Chrome -headless --remote-url http://selenium__standalone-chrome:4444/wd/hub testing/
  artifacts:
    when: always
    reports:
      junit: report.xml

Generates:

---------------------------- Captured stdout call -----------------------------
 Dash is running on http://127.0.0.1:8050/
 Dash is running on http://127.0.0.1:8050/
 Dash is running on http://127.0.0.1:8050/
 Dash is running on http://127.0.0.1:8050/
 Dash is running on http://127.0.0.1:8050/
 Dash is running on http://127.0.0.1:8050/
 2021-04-23 14:27:21,034 | dash - INFO: Dash is running on http://127.0.0.1:8050/
  * Serving Flask app "app.app" (lazy loading)
  * Environment: production
    WARNING: This is a development server. Do not use it in a production deployment.
    Use a production WSGI server instead.
  * Debug mode: off
 2021-04-23 14:27:21,051 | _internal - INFO:  * Running on http://127.0.0.1:8050/ (Press CTRL+C to quit)
 2021-04-23 14:27:21,164 | dashboard - INFO: Serving layout...
 2021-04-23 14:27:21,166 | app_cache - DEBUG: retrieving from cache: select distinct country from results
 2021-04-23 14:27:21,183 | _internal - INFO: 127.0.0.1 - - [23/Apr/2021 14:27:21] "GET / HTTP/1.1" 200 -
 ------------------------------ Captured log call -------------------------------
 INFO     app.app:dash.py:1714 Dash is running on http://127.0.0.1:8050/
 INFO     werkzeug:_internal.py:113  * Running on http://127.0.0.1:8050/ (Press CTRL+C to quit)
 INFO     werkzeug:_internal.py:113 127.0.0.1 - - [23/Apr/2021 14:27:21] "GET / HTTP/1.1" 200 -
 --------------------------- Captured stdout teardown ---------------------------
 2021-04-23 14:27:23,110 | _internal - INFO: 127.0.0.1 - - [23/Apr/2021 14:27:23] "GET /_stop-adc0916c7cdb4b169e4eeb4c3f3f532e HTTP/1.1" 200 -
 ---------------------------- Captured log teardown -----------------------------
 INFO     werkzeug:_internal.py:113 127.0.0.1 - - [23/Apr/2021 14:27:23] "GET /_stop-adc0916c7cdb4b169e4eeb4c3f3f532e HTTP/1.1" 200 -
 _______________________________ test_tab_styles ________________________________
 dash_duo = <dash.testing.composite.DashComposite object at 0x7f14d260f610>
     def test_tab_styles(dash_duo):
 >       dash_duo.start_server(app)
 testing/test_db_tabs.py:28: 
 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
 /usr/local/lib/python3.9/site-packages/dash/testing/composite.py:16: in start_server
     self.server_url = self.server.url
 /usr/local/lib/python3.9/site-packages/dash/testing/browser.py:601: in server_url
     self.wait_for_page()
 /usr/local/lib/python3.9/site-packages/dash/testing/browser.py:341: in wait_for_page
     self.driver.get(self.server_url if url is None else url)
 /usr/local/lib/python3.9/site-packages/selenium/webdriver/remote/webdriver.py:333: in get
     self.execute(Command.GET, {'url': url})
 /usr/local/lib/python3.9/site-packages/selenium/webdriver/remote/webdriver.py:321: in execute
     self.error_handler.check_response(response)
 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
 self = <selenium.webdriver.remote.errorhandler.ErrorHandler object at 0x7f14d260fdc0>
 response = {'status': 500, 'value': '{"value":{"error":"unknown error","message":"unknown error: net::ERR_CONNECTION_REFUSED\\n  (Session info: chrome=90.0.4430.85)","stacktrace":"#0 0x563f07a8ee89 \\u003Cunknown>\\n"}}'}

[DKilkenny]

I'm having this error myself. Wondering if you or anyone else have found a solution to the issue?

[diegolpedro]

Hi. I am having the same issue too. Do you find any solution?

EDIT: I found a solution. Beeing explicit on server setup. Wrote "app.run_server(host='0.0.0.0',debug=True, port=8050)" intead of "app.run_server(debug=True)"