andrewvy/ansible-elixir

Simple role for deploying Elixir Exrm releases.

Ansible Elixir Role

Simple deployment role for Exrm-based releases

Installation

ansible-galaxy install andrewvy.elixir

Or manually, by cloning the repo. :)

Make sure you have exrm listed in your mix.exs dependencies!

  defp deps do
    [{:phoenix, "~> 1.0.0"},
     {:phoenix_html, "~> 2.1"},
     {:phoenix_live_reload, "~> 1.0", only: :dev},
     {:phoenix_ecto, "~> 1.1"},
     {:postgrex, ">= 0.0.0"},
     {:cowboy, "~> 1.0"},
     {:exrm, "~> 0.19.9"}
   ]

Also, you may run into Common Issues with Exrm

In my case, I had to add to my mix.exs applications..

:postgrex, :phoenix_ecto

  def application do
    [mod: {Chat, []},
     applications: [:phoenix, :phoenix_html, :cowboy, :logger, :postgrex, :phoenix_ecto]]
  end

Setup

First, you need to make sure what your host layout looks like.

I'm running this role with a dedicated build server that separates the compile process from the actual running server environment.

You must make sure that the server that does the compiling has git access to your repo.

This is because the compiled server will commit and tag the released version to your repo.

You can achieve this either through SSH Agent Forwarding, or by registering your build server's SSH keys with GitHub.

Next, you need to make sure that your compile server has erlang and elixir installed. This role doesn't handle those dependencies, I highly recommend using ohr486.elixir

However, the setup action will install Hex and Rebar for you. Which ohr486 does not do.

setup-playbook.yml

---
- hosts: build_servers
  sudo: yes
  roles:
    - { role: ohr486.elixir, erlang_version: 18.1, elixir_version: v1.1.1 }
    - { role: "andrewvy.elixir", action: "setup" }

Next, you can create your deploy playbook. Here's my example:

---
- hosts: build_servers
  sudo: no
  vars:
    repo_url: git@github.com:CHANGEME
    app_name: CHANGEME
  roles:
    - { role: "andrewvy.elixir", action: "build" }

- hosts: production
  sudo: no
  vars:
    app_name: CHANGEME
  roles:
    - { role: "andrewvy.elixir", action: "start" }

But, you can easily do compiling + deploying on the same server.

---
- hosts: production
  sudo: no
  vars:
    repo_url: git@github.com:CHANGEME
    app_name: CHANGEME
  roles:
    - { role: "andrewvy.elixir", action: "build" }
    - { role: "andrewvy.elixir", action: "start" }

You must define a repo_url and app_name. And you must define the build role first.

After you have first successfully deployed with the action: start, you can then swap it out for upgrade for hot-code upgrades. :)

Actions:

Here are the different actions:

setup - will initially setup the server for compiling.

build - will compile the release tar, commit and tag it, and push it up.

start - will use the compiled release tar, and restart the server with it.

upgrade - will use the compiled release tar, and perform hot-code upgrade.

Variables

repo_url - (REQUIRED) Used to pull down the repo when compiling.

app_name - (REQUIRED) This is what is defined in your mix.exs file.

app_port - (OPTIONAL) This is what port your app will be exposed as. Default: 3000

git_ref - (OPTIONAL) This is what branch is pulled when compiling. Default: master

projects_dir - (OPTIONAL) This is where we temporarily pull down repos and compile releases. Default: /tmp/projects

mix_env - (OPTIONAL) This is what environment your app will be compiled to. Default: prod