Prepare app for releases by moving configuration to runtime

.gitignore

@@ -9,6 +9,9 @@ config.exs
 # Configs
 config/*.exs
 
+# Release
+/rel
+
 # Static artifacts
 /node_modules
 /bower_components

config/config.exs.dist

@@ -54,6 +54,8 @@ config :mebe_web,
   # Set to true for any view you want to use custom templates for.
   # If using custom templates for a view, create a folder web/templates/custom/<viewname>
   # and make a copy of all templates for the view inside the folder.
+  # Note that releases will always use the custom templates that were set in
+  # the configuration file at release creation time.
   custom_templates: %{
     "ErrorView" => false,
     "FeedView" => false,

lib/mebe_engine/worker.ex

@@ -7,8 +7,7 @@ defmodule MebeEngine.Worker do
 
   alias MebeEngine.Crawler
   alias MebeEngine.DB
-
-  @data_path Application.get_env(:mebe_web, :data_path)
+  alias MebeWeb.Utils
 
   def start_link(opts \\ []) do
     GenServer.start_link(__MODULE__, :ok, opts)
@@ -36,7 +35,9 @@ defmodule MebeEngine.Worker do
   Initialize the database by crawling the configured path and parsing data to the DB.
   """
   def load_db() do
-    Logger.info "Loading post database from '#{@data_path}'…"
+    data_path = Utils.get_conf :data_path
+
+    Logger.info "Loading post database from '#{data_path}'…"
 
     %{
       pages: pages,
@@ -44,7 +45,7 @@ defmodule MebeEngine.Worker do
       tags: tags,
       years: years,
       months: months,
-    } = Crawler.crawl @data_path
+    } = Crawler.crawl data_path
 
     Logger.info "Loaded #{Enum.count pages} pages and #{Enum.count posts} posts."
 

lib/utils.ex

@@ -0,0 +1,15 @@
+defmodule MebeWeb.Utils do
+  @moduledoc """
+  This module contains functions and other stuff that just don't fit anywhere else properly.
+  """
+
+  @doc """
+  Get a configuration setting.
+
+  Uses Application.get_env to get the given setting's value. Use this instead of module attributes
+  so the configuration settings are not compiled in!
+  """
+  def get_conf(key) do
+    Application.get_env :mebe_web, key
+  end
+end

mix.exs

@@ -4,8 +4,6 @@ defmodule MebeWeb.Mixfile do
   def project do
     [app: :mebe_web,
      version: "1.0.0",
-     deps_path: "deps",
-     lockfile: "mix.lock",
      elixir: "~> 1.1.0",
      elixirc_paths: elixirc_paths(Mix.env),
      compilers: [:phoenix] ++ Mix.compilers,
@@ -19,7 +17,7 @@ defmodule MebeWeb.Mixfile do
   # Type `mix help compile.app` for more information
   def application do
     [mod: {MebeWeb, []},
-     applications: [:phoenix, :cowboy, :logger]]
+     applications: [:phoenix, :cowboy, :logger, :phoenix_html, :earmark, :conform]]
   end
 
   # Specifies which paths to compile per environment
@@ -35,7 +33,9 @@ defmodule MebeWeb.Mixfile do
       {:phoenix_live_reload, "~> 1.0", only: :dev},
       {:phoenix_html, "~> 2.2"},
       {:cowboy, "~> 1.0"},
-      {:earmark, "~> 0.1.16"}
+      {:earmark, "~> 0.1.16"},
+      {:exrm, "~> 1.0.0-rc5"},
+      {:conform, "~> 1.0.0-rc4"}
    ]
   end
 end

mix.lock

@@ -1,10 +1,18 @@
-%{"cowboy": {:hex, :cowboy, "1.0.4"},
+%{"bbmustache": {:hex, :bbmustache, "1.0.3"},
+  "conform": {:hex, :conform, "1.0.0-rc4"},
+  "cowboy": {:hex, :cowboy, "1.0.4"},
   "cowlib": {:hex, :cowlib, "1.0.2"},
   "earmark": {:hex, :earmark, "0.1.19"},
+  "erlware_commons": {:hex, :erlware_commons, "0.15.0"},
+  "exrm": {:hex, :exrm, "1.0.0-rc5"},
   "fs": {:hex, :fs, "0.9.2"},
+  "getopt": {:hex, :getopt, "0.8.2"},
+  "neotoma": {:hex, :neotoma, "1.7.3"},
   "phoenix": {:hex, :phoenix, "1.0.3"},
   "phoenix_html": {:hex, :phoenix_html, "2.2.0"},
   "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.0.1"},
   "plug": {:hex, :plug, "1.0.2"},
   "poison": {:hex, :poison, "1.5.0"},
-  "ranch": {:hex, :ranch, "1.2.0"}}
+  "providers": {:hex, :providers, "1.4.1"},
+  "ranch": {:hex, :ranch, "1.2.0"},
+  "relx": {:hex, :relx, "3.5.0"}}

web/controllers/controller_utils.ex

@@ -1,20 +1,12 @@
 defmodule MebeWeb.ControllerUtils do
   use MebeWeb.Web, :controller
 
+  alias MebeWeb.Utils
+
   @moduledoc """
   This module contains the common functions for all controllers.
   """
 
-  @blog_name Application.get_env(:mebe_web, :blog_name)
-  @blog_author Application.get_env(:mebe_web, :blog_author)
-  @absolute_url Application.get_env(:mebe_web, :absolute_url)
-  @posts_per_page Application.get_env(:mebe_web, :posts_per_page)
-  @disqus_comments Application.get_env(:mebe_web, :disqus_comments)
-  @page_commenting Application.get_env(:mebe_web, :page_commenting)
-  @disqus_shortname Application.get_env(:mebe_web, :disqus_shortname)
-  @feeds_enabled Application.get_env(:mebe_web, :enable_feeds)
-  @force_read_more Application.get_env(:mebe_web, :force_read_more)
-
   @doc """
   Render a list of posts with the given template and params. The posts
   and generic configuration settings are assigned to the connection.
@@ -31,14 +23,24 @@ defmodule MebeWeb.ControllerUtils do
   """
   def insert_config(conn) do
     conn
-    |> assign(:blog_name, @blog_name)
-    |> assign(:blog_author, @blog_author)
-    |> assign(:absolute_url, @absolute_url)
-    |> assign(:posts_per_page, @posts_per_page)
-    |> assign(:disqus_comments, @disqus_comments)
-    |> assign(:page_commenting, @page_commenting)
-    |> assign(:disqus_shortname, @disqus_shortname)
-    |> assign(:feeds_enabled, @feeds_enabled)
-    |> assign(:force_read_more, @force_read_more)
+    |> assign(:blog_name, Utils.get_conf(:blog_name))
+    |> assign(:blog_author, Utils.get_conf(:blog_author))
+    |> assign(:absolute_url, Utils.get_conf(:absolute_url))
+    |> assign(:posts_per_page, Utils.get_conf(:posts_per_page))
+    |> assign(:disqus_comments, Utils.get_conf(:disqus_comments))
+    |> assign(:page_commenting, Utils.get_conf(:page_commenting))
+    |> assign(:disqus_shortname, Utils.get_conf(:disqus_shortname))
+    |> assign(:feeds_enabled, Utils.get_conf(:feeds_enabled))
+    |> assign(:force_read_more, Utils.get_conf(:force_read_more))
+  end
+
+  @doc """
+  Render the 404 page.
+  """
+  def render_404(conn) do
+    conn
+    |> insert_config
+    |> put_status(:not_found)
+    |> render(MebeWeb.ErrorView, :"404")
   end
 end

web/controllers/feed_controller.ex

@@ -2,8 +2,10 @@ defmodule MebeWeb.FeedController do
   use MebeWeb.Web, :controller
 
   alias MebeEngine.DB
-  import MebeWeb.ControllerUtils, only: [render_posts: 4]
+  alias MebeWeb.Utils
+  import MebeWeb.ControllerUtils, only: [render_posts: 4, render_404: 1]
 
+  plug :check_feeds_enabled
   plug :put_resp_content_type, "application/rss+xml"
   plug :put_layout_formats, ["xml"]
   plug :put_layout, "feed.xml"
@@ -26,4 +28,18 @@ defmodule MebeWeb.FeedController do
     |> assign(:tag, tag)
     |> render_posts(posts, "postlist.xml", params)
   end
+
+  # A private plug to check if feeds are enabled at runtime. We need to do this
+  # at runtime to make it work with releases (where the release is compiled with
+  # configuration that was active when the release was made). This plug will halt
+  # the request processing, returning a 404 error if feeds are not enabled.
+  defp check_feeds_enabled(conn, _opts) do
+    case Utils.get_conf :enable_feeds do
+      true -> conn
+      false ->
+        conn
+        |> render_404
+        |> halt
+    end
+  end
 end

web/controllers/page_controller.ex

@@ -2,9 +2,8 @@ defmodule MebeWeb.PageController do
   use MebeWeb.Web, :controller
 
   alias MebeEngine.DB
-  import MebeWeb.ControllerUtils, only: [render_posts: 4, insert_config: 1]
-
-  @posts_per_page Application.get_env(:mebe_web, :posts_per_page)
+  alias MebeWeb.Utils
+  import MebeWeb.ControllerUtils, only: [render_posts: 4, insert_config: 1, render_404: 1]
 
   def index(conn, params) do
     conn
@@ -153,16 +152,11 @@ defmodule MebeWeb.PageController do
   end
 
   defp calculate_ranges(page) do
+    posts_per_page = Utils.get_conf :posts_per_page
+
     {
-      (page - 1) * @posts_per_page,
-      @posts_per_page
+      (page - 1) * posts_per_page,
+      posts_per_page
     }
   end
-
-  defp render_404(conn) do
-    conn
-    |> insert_config
-    |> put_status(:not_found)
-    |> render(MebeWeb.ErrorView, :"404")
-  end
 end

web/router.ex

@@ -1,8 +1,6 @@
 defmodule MebeWeb.Router do
   use Phoenix.Router
 
-  @enable_feeds Application.get_env(:mebe_web, :enable_feeds)
-
   pipeline :browser do
     plug MebeWeb.RequestStartTimePlug
     plug :accepts, ["html", "xml"]
@@ -16,11 +14,11 @@ defmodule MebeWeb.Router do
 
     get "/p/:page", PageController, :index
     get "/", PageController, :index
-    if @enable_feeds, do: (get "/feed", FeedController, :index)
+    get "/feed", FeedController, :index
 
     get "/tag/:tag/p/:page", PageController, :tag
     get "/tag/:tag", PageController, :tag
-    if @enable_feeds, do: (get "/tag/:tag/feed", FeedController, :tag)
+    get "/tag/:tag/feed", FeedController, :tag
 
     get "/archive/:year/p/:page", PageController, :year
     get "/archive/:year", PageController, :year

web/templates/layout/app.html.eex

@@ -4,7 +4,7 @@
     <meta charset="utf-8">
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta name="author" content="<%= Application.get_env :mebe_web, :blog_author %>">
+    <meta name="author" content="<%= @blog_author %>">
 
     <title><%= title @conn %></title>
     <link rel="stylesheet" href="<%= static_path(@conn, "/css/app.css") %>">

web/views/error_view.ex

@@ -1,7 +1,7 @@
 defmodule MebeWeb.ErrorView do
   use MebeWeb.Web, :view
 
-  @absolute_url Application.get_env(:mebe_web, :absolute_url)
+  alias MebeWeb.Utils
 
   def render("404.html", %{conn: conn}) do
     render "not_found.html", %{conn: conn}
@@ -20,5 +20,5 @@ defmodule MebeWeb.ErrorView do
   @doc """
   Get the home page URL of the site.
   """
-  def home_url(), do: @absolute_url
+  def home_url(), do: Utils.get_conf :absolute_url
 end

web/views/feed_view.ex

@@ -1,7 +1,7 @@
 defmodule MebeWeb.FeedView do
   use MebeWeb.Web, :view
 
-  @feeds_full_content Application.get_env(:mebe_web, :feeds_full_content)
+  alias MebeWeb.Utils
 
-  def show_full(), do: @feeds_full_content
+  def show_full(), do: Utils.get_conf :feeds_full_content
 end

web/views/layout_view.ex

@@ -1,10 +1,7 @@
 defmodule MebeWeb.LayoutView do
   use MebeWeb.Web, :view
 
-  @default_title Application.get_env(:mebe_web, :blog_name)
-  @extra_html Application.get_env(:mebe_web, :extra_html)
-
-  @feeds_enabled Application.get_env(:mebe_web, :enable_feeds)
+  alias MebeWeb.Utils
 
   @doc """
   Resolve title from the current assigns. Will use the current page's or post's title, if available.
@@ -18,23 +15,14 @@ defmodule MebeWeb.LayoutView do
       conn.assigns[:page] ->
         conn.assigns[:page].title
 
-      true -> @default_title
+      true -> Utils.get_conf :blog_name
     end
   end
 
   @doc """
   Return the extra HTML defined in the config.
   """
-  def extra_html(), do: @extra_html
-
-  if not @feeds_enabled do
-    @doc """
-    If feeds are not enabled, mock the feed_path functions so that compilation does not crash because
-    of missing feed_path.
-    """
-    def feed_path(_, _), do: nil
-    def feed_path(_, _, _), do: nil
-  end
+  def extra_html(), do: Utils.get_conf :extra_html
 
   @doc """
   Calculate time taken for request so far.

web/web.ex

@@ -16,6 +16,8 @@ defmodule MebeWeb.Web do
   below.
   """
 
+  alias MebeWeb.Utils
+
   def controller do
     quote do
       use Phoenix.Controller
@@ -30,7 +32,9 @@ defmodule MebeWeb.Web do
       root = "web/templates"
 
       # Check if we should be using a custom template
-      custom_templates = Application.get_env :mebe_web, :custom_templates
+      # TODO: Enable custom views even for releases, currently always set to off
+      # because they use compile time configuration
+      custom_templates = Utils.get_conf :custom_templates
       compiled_view = MebeWeb.Web.module_to_str __MODULE__
 
       if Map.get custom_templates, compiled_view do