juhalehtonen / docknix

Docknix

A Dockerized, zero-dependency Phoenix 1.3 setup which should be used as a sample for future setups. Based on Gist by jswny.

Includes everything needed to build, deploy and run a default Phoenix application (Nginx and PostgreSQL).

Quickstart

Assuming you just want to build and run this application with everything already configured properly:

# Locally
./build.sh

# On the server
docker network create nginx-network
docker-compose up # in app diretory
docker-compose up # in nginx directory

For CI (and building with Docker in general), we need the following environment variables set:

• DOCKNIX_RELEASE_COOKIE for the distributed Erlang cookie
• DOCKNIX_SECRET_KEY_BASE for Phoenix secret key base
• DOCKNIX_DB_USER for PostgreSQL username
• DOCKNIX_DB_PASS for PostgreSQL password

Additionally, for CircleCI:

• APP_HOST to know where to deploy to with CI
• APP_USER to define which user to deploy as with CI

All the steps

Below is a quick outline of the steps we needed to take to achieve this setup.

Lines with * signify files that you might need to change (e.g. app names).

Steps for Phoenix and Distillery

1. Add Distillery to dependencies in mix.exs: {:distillery, "~> 1.5", runtime: false}
2. Run mix do deps.get, compile to fetch and compile Distillery
3. Run mix release.init to initialize a Distillery release
4. Configure if we want to include erts in rel/config.exs *
5. Create release tasks module in lib/docknix/release_tasks.ex *
6. Add release command script at rel/commands/migrate.sh *
7. Add release command script to list of commands in rel/config.exs (to be able to run migrations with bin/docknix migrate)

Steps for Docker

8. Add .dockerignore to avoid including unnecessary files
9. Create Dockerfile.build to specify how to build the release *
10. Create build.sh to manage the building of the app *
11. You can now run ./build.sh to build your application in Docker
12. Create Dockerfile.run for running the built release *
13. Add docker-compose.yml to provision and manage the containers *

More steps for Phoenix

14. Adjust config/prod.exs to follow Distillery basics *
15. Adjust config/prod.secret.exs for production secrets *

Steps for Nginx @ Docker

16. Create a Docker network with docker network create nginx-network
17. Create directories nginx and nginx/conf.d and place docker-compose.yml and Nginx configs there

Steps for running everything

18. Assume we have already run docker network create nginx-network
19. Run docker-compose up in application directory
20. Run docker-compose up in nginx directory

Phoenix locally

To start your Phoenix server:

• Install dependencies with mix deps.get
• Create and migrate your database with mix ecto.create && mix ecto.migrate
• Install Node.js dependencies with cd assets && npm install
• Start Phoenix endpoint with mix phx.server

Now you can visit localhost:4000 from your browser.

Ready to run in production? Please check our deployment guides.

Learn more

• 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