ElixirChat

This sample application demonstrates how it might look to develop with Elixir and the Phoenix framework, with server deployments via Docker.

It happens to be a simple chatroom using Phoenix's Channels -- a thin abstraction over websockets to allow for flexible sending and consumption of messages between different technologies. But the main purpose of this application is to show how an Elixir app can be constructed, built into a release, and deployed via Docker.

To start your Phoenix server, do the following steps. See below if you get any SSL or certificate errors.

Install dependencies with mix deps.get
Install Node.js dependencies with cd assets && npm install && cd ..
Start Phoenix endpoint with mix phx.server

Now you can visit localhost:4000 from your browser.

Using Docker as a Development Environment

After checking out this repository to your local machine, simply cd into the new project directory and enter these two commands.

assets/dev-env/go.sh
mix deps.get
cd assets; npm install; cd ..
imp

The first will launch the fish shell inside the dev environment docker container, building it if necessary. The second is a shell alias for iex -S mix phx.server. See the fish config for this and other aliases.

Building and Running a Release Under Docker

Distillery is the Elixir tool that helps us build our application into a "release", the preferred form of an application for deployment to a server. As a release, The Elixir and Erlang source code has been compiled to pure bytecode, ready to be executed by the BEAM (the Virtual Machine) itself.

For our demonstration, we will be building our release directly to a Docker container. To set this up, we've followed the guide provided by the Distillery project.

Make sure you have Docker installed and running, and you can build the application with:

make build

You now have a minimal Docker image with Alpine Linux, the BEAM, and your application bytecode. To run the container locally, simply run:

make run

The application should now be accessible at http://localhost:4000/.

Learn More About Elixir

Elixir School - Fantastic crash course in the Elixir language
Awesome Elixir - Exhaustive list of Elixir libraries, communities, tools, and learning resources

Learn More About Phoenix

Official website: http://www.phoenixframework.org/
Guides: http://phoenixframework.org/docs/overview
Docs: https://hexdocs.pm/phoenix
Mailing list: http://groups.google.com/group/phoenix-talk
Source: https://github.com/phoenixframework/phoenix

Fix Certificate Issues on QL Network

Because of the way our network is connected to the internet, you may get errors from npm or hex (Elixir's package manager). The simplest fix is to ignore the issuer of the certificates that are used for these secure connections. Try the following:

Set the SET_UNSAFE_HTTPS environment variable to 1:
- In bash: export SET_UNSAFE_HTTPS=1
- In fish: set -x SET_UNSAFE_HTTPS 1
Set the NODE_TLS_REJECTED_UNAUTHORIZED environment variable to 0:
- In bash: export NODE_TLS_REJECTED_UNAUTHORIZED=0
- In fish: set -x NODE_TLS_REJECTED_UNAUTHORIZED 0
These commands may help, too:
- npm set strict-ssl false
- npm set strict-ssl -g false

Of course you may want to add the environment variable settings to your ~/.bashrc or ~/.config/fish/config.fish so they take effect for future terminal sessions.

Credits

Big thanks to the community and the countless tools we're building on to make building this app so simple, but also thanks to phoenix-chat-example for the frontend JavaScript which I have lightly modified.

djthread / elixir_chat