Adds gigalixir deploy setup and documentation (#39)

* Adds gigalixir deploy setup and documentation

Signed-off-by: Tallys Martins <tallysmartins@gmail.com>

* Apply review changes

Author: tallysmartins

.buildpacks

@@ -0,0 +1,3 @@
+https://github.com/gigalixir/gigalixir-buildpack-clean-cache.git
+https://github.com/HashNuke/heroku-buildpack-elixir
+https://github.com/gigalixir/gigalixir-buildpack-distillery.git

README.md

@@ -32,7 +32,40 @@ Now you can visit [`localhost:4000/api/graphiql`](http://localhost:4000/api/grap
 
 ## Deployment
 
-To build the release you can use `mix release`. The relese requires a `PORT` environment variable.
+This project uses `distillery` for deployments. The relese requires `PORT` and
+`DATABASE_URL` environment variables. Built releases are placed under `_build/prod/rel/elixir_bench`
+directory
+
+```
+$ MIX_ENV=prod mix release --env=prod
+```
+
+Start the application passing the required variables
+
+```
+DATABASE_URL="postgresql://user:password@localhost:5432/elixir_bench_dev" PORT=4000 _build/prod/rel/elixir_bench/bin/elixir_bench foreground
+```
+
+**PS:** If you try to build a release with an environment other than prod, **IT WILL FAIL**
+as development and test environments rely on Mix wich is not shipped within the releases and
+require substantial changes to work.
+
+## Deploy on Gigalixir
+
+This project ships the configuration needed to deploy on [Gigalixir](https://gigalixir.com), a Heroku like
+service. To make a deploy on Gigalixir you will have to follow this simple guide and refer
+to the documentation for further information, see [Getting Started](https://gigalixir.readthedocs.io/en/latest/main.html#getting-started-guide)
+
+- Install the Gigalixir CLI, all steps are performed through it
+- Create an account and login
+- Create an app and give it a name
+- Add a database to your app
+- Push your code to gigalixir and see the magic happening
+
+**This project uses the `uuid-ossp extension` from postgresql which is added
+in `priv/repo/migrations/20171210214237_add_uuid_to_job.exs`. Gigalixir does not
+allow any extensions in the free tier plan, so a workaround is to remove it from
+the migration to not use this extension or drop a few bucks :)**
 
 ## License
 

config/prod.exs

@@ -14,9 +14,20 @@ use Mix.Config
 # manifest is generated by the mix phx.digest task
 # which you typically run after static files are built.
 config :elixir_bench, ElixirBenchWeb.Endpoint,
+  # Dynamically verify and set Endpoint env variables
   load_from_system_env: true,
+  http: [],
+  server: true,
   url: [host: "elixirbench.org", port: 80],
-  cache_static_manifest: "priv/static/cache_manifest.json"
+  secret_key_base: "${SECRET_KEY_BASE}"
+
+# Configure your database
+config :elixir_bench, ElixirBench.Repo,
+  # Dynamically verify and set Repo env variables
+  load_from_system_env: true,
+  adapter: Ecto.Adapters.Postgres,
+  ssl: true,
+  pool_size: 1
 
 # Do not print debug messages in production
 config :logger, level: :info
@@ -46,11 +57,5 @@ config :logger, level: :info
 #
 # Check `Plug.SSL` for all available options in `force_ssl`.
 
-config :elixir_bench, ElixirBenchWeb.Endpoint, server: true
-
-# Finally import the config/prod.secret.exs
-# which should be versioned separately.
-import_config "prod.secret.exs"
-
 # Set the Github client
 config :elixir_bench, :github_client, ElixirBench.Github.ClientHTTP

lib/elixir_bench/repo.ex

@@ -12,7 +12,15 @@ defmodule ElixirBench.Repo do
   Dynamically loads the repository url from the
   DATABASE_URL environment variable.
   """
-  def init(_, opts) do
-    {:ok, Keyword.put(opts, :url, System.get_env("DATABASE_URL"))}
+  def init(_, config) do
+    if config[:load_from_system_env] do
+      database_url =
+        System.get_env("DATABASE_URL") ||
+          raise "expected the DATABASE_URL environment variable to be set"
+
+      {:ok, Keyword.put(config, :url, database_url)}
+    else
+      {:ok, config}
+    end
   end
 end