Greetings,

I am just learning Elixir and Phoenix. I finished the elixir-lang.org tutorial and a bit of Phoenix. While I’m still not very confident in the language yet, I am extremely impressed so far.

Basically, I have a social media site (we’ll say example.com). It is developed using PHP/MySQL and I built a Node.js chat app a few years back just to learn about sockets and build some simple chat features, like one page with a big 1990s style chat room where everyone on the site can chat on one page, live private messaging for users to chat among people only on their friends list, and live web cam chat. I was successful in getting all of that set up, and haven’t touched it in years. From the beginning, I was never comfortable with Node.js and how one crash anywhere in the app causes the whole thing to crash completely, and how it simply didn’t have as much capability in case our site one day became popular with tons of users. I always hated “callback hell” as well… After reading about chat apps, I always knew that someday I would eventually learn Phoenix/Elixir to replace Node.js.

Right now, I have Ubuntu 20.04. When I login to my shell using the “ubuntu” user (like a root user), I installed Phoenix and set up a project in the ubuntu username directory “/home/ubuntu/chatter/”, the app name is “chatter”. I’ve been making some good progress getting the simple chat example to work, Presence to work and that awesome LiveDashboard working. Really impressed on how all those things just “worked” right out of the box without any arcane configurations.

I am running this stuff on my generic IP address, like [xxx.xxx.xxx.xxx]:4000 and through the shell. So now I have some questions on starting up a real project on the website itself.

First question: If my website directory is in: “/home/example/example.com”, what is the common practice for where where you would install the new project for use in production? Do I install it in “/home/example/chatter”, or “/home/example/example.com/chatter”? I’m seeing that in a standard install, some files are server stuff, and other are “assets”, which is stuff that I think goes in the website directory for browsers to load the JavaScript files. Or do I install it under the user “example” or directory: “/home/example/chatter” and copy and paste the “asset” files into the “/home/example/example.com/assets”?

Next question, for UFW firewall rules for port “4000”, should I set the “Allow” flag for 0.0.0.0 for everyone on the internet to access, or is there a common security practice for this for setting it up on a public-facing website? Phoenix will run on the same server as my website.

Lastly, how do I run Phoenix and my “chatter” app non-stop and have it automatically restart in case the server crashes? I’m cheap right now, so my server does sometimes crash from running out of memory every once in awhile. so I’m going to need my app to fire back up automatically again after reboots, crashes and server restarts, especially I’m sleeping and can’t get to the shell until I wake up.

Thanks