Check the 'Source Control Management' section, and validate the LAST COMMIT is correct:
nex-cli apps:info my-app
If the status is 'ACTIVE', your deployment should be ok & running.
If the status is 'restarting' and it has beens some time, then it may be having troubles starting and is worth investigating the cubes.
List the cubes for your app:
nex-cli cubes --app my-app --all
SSH into the rack via the cubes IP address listed from the command above with:
nex-cli racks:ssh 10.0.1.234
List the docker containers to check the status:
sudo su docker ps -a
If a container "exited" (should say in the status), there is something wrong. View the logs:
docker logs CONTAINER-NAME
Hopefully you have identified your issue :)
Resetting the Nex! rack lock
Sometimes Nex! seems to lose control of cubes, if one is stuck and not restarting, try deleting the Nex! locks in the racks:ssh machine:
rm -f /var/lock/nex/*