Ports not accessible from host in v1.12-rc2-beta16

In docker for mac v1.11 our Rails app built successfully without issue. The site was accessible from the host. Once the upgrade to v1.12 occurred, the app is no longer accessible from the host however the container appears to build correctly. The app logs (Rails production.log & Thin server log) appear normal with no errors indicating that the web server isn’t starting.

The docker logs show this line which could point to the issue: 6/28/16 9:10:33.402 PM Docker[669]: tcp: proxy failed with flow proxy b: write failed with Eof

Running curl in the container returns 200 however running curl outside the container returns curl: (52) Empty reply from server


We have a scripted deployment but the final docker run command (where the ports are forwarded) is this:
docker run -it -d -v #{@deploy_dir}/llp:/home/app/llp -v #{@deploy_dir}/te-api:/home/app/te-api -v #{@host_db_dir}:/var/lib/mysql -v #{@host_upload_dir}:/home/app/llp/public/uploads -p ll_app /var/start_services.sh

Docker for Mac: version: mac-v1.12.0-beta16.2
OS X: version 10.11.5 (build: 15F34)
logs: /tmp/20160628-211214.tar.gz
failure: No error was detected
[OK] docker-cli
[OK] app
[OK] menubar
[OK] virtualization
[OK] system
[OK] osxfs
[OK] db
[OK] slirp
[OK] moby-console
[OK] logs
[OK] vmnetd
[OK] env
[OK] moby
[OK] driver.amd64-linux

I’ve taken a look at quite a few posts like these here and here but can’t figure out what’s wrong. Any assistance is greatly appreciated.

Just in case someone comes across this, I found a solution after chasing my tail for a few days.

I just had to reset docker in the preference pane. Then, after rebuilding the container, the ports were working as expected. Not sure what happened when docker got updated but something broke and was fixed with the reset.

Hope that helps.