I have some Selenium Webdriver/Capybara automation setup in a ruby app. Along with this in a VirtualBox VM using Linux I have a docker container for Selenium grid docker run -d -p 4444:4444 --name selenium-hub -e GRID_TIMEOUT=120000 selenium/hub:2.53.0 and a firefox node docker run -d --link selenium-hub:hub selenium/node-firefox:2.53.0. After adding a DNS entry to docker_opts on the VM, in my host machine if I run my Selenium test (which uses the grid on my VM) everything works fine.
After this I setup my automation code in a ruby container on my vm along side the grid and containers. The container builds just fine. I am also able to attach to it without issue and all my code is there as expected. from the terminal in my automation container if attempt to run a spec ex. rspec spec/some_spec.rb I will get a connection refused error
"Failed to open TCP connection to 127.0.0.1:4444 (Connection refused - connect(2) for \"127.0.0.1\" port 4444)"
of the 18 results googling up this issue the only thing I saw that seemed actionable mentioned creating a bridge, which I don't really understand. Any suggestions on how to correct this would be greatly appreciated.
It's not easy to say without seeing your specs but I'm guessing you connect to selenium on 127.0.0.1:4444 in your tests?
If so you should now connect to it on hub:4444 as that is the name which will resolve to the IP of your selenium hub container.