You should build your release on a machine that runs the same operating system in the same version with the same library versions.

Since you said your local machine is a Mac and your remote is a Ubuntu, you should either build on the target (which I’d not recommend) or in a Ubuntu 16.04 VM on your Mac.

I followed that tutorial and managed to get my site up but it took me a few days to figure it out. I had a hard time because I’m not very familiar with the devops part of stuff like nginx. It also was annoying because it costs money every month even for the smallest droplet and for a hobby or new app that you are just trying to get deployed it’s not worth it in my opinion.

Either way, when it came to troubleshooting I remember there were logs being saved somewhere on the server that you should be able to pull up about your app and it’ll give you some clues. These were erlang logs I think. I wish I could be more specific but It’s been a while.

The fastest route to deployment has been heroku in my experience. But after trying to internalize the “phoenix is not your app” mantra and get a better handle on what it means to leverage OTP, it’s hard to justify using Heroku since it has to reset its dynos daily, effectively killing any long-running processes.

My most recent project I decided to try gigalixir which I have to say so far, I am thoroughly impressed. Amazing documentation. Insane customer service! You get hot code upgrades and all that stuff baked in. And the free tier is sufficient for most hobby apps.

Try this template: GitHub - cogini/elixir-deploy-template: An example project for deploying Elixir · GitHub
It is a step-by-step process for building and deploying a Phoenix app using Ansible.
I have been testing it on a Digital Ocean droplet with CentOS 7, Ubuntu 16.04 and 18.04.

I am preparing it as part of this guide:

Please give me your feedback / questions.