Use ExAws instead of Erlcloud

CHANGELOG.md

@@ -1,5 +1,31 @@
 # Changelog
 
+## v0.2.0 (12-11-2015)
+  * (Breaking Change) Erlcloud has been removed in favor of ExAws.
+  * (Enhancement) Added a configuration parameter to generate urls in the `virtual_host` style.
+
+### Upgrade Instructions
+Since `erlcloud` has been removed from `arc`, you must also remove it from your dependency graph as well as your application list. In its place, add `ex_aws` and `httpoison` to your dependencies as well as application list. Next, remove the aws credential configuration from arc:
+
+```elixir
+# BEFORE
+config :arc,
+  access_key_id: "###",		
+  secret_access_key: "###",		
+  bucket: "uploads"
+
+#AFTER
+config :arc,
+  bucket: "uploads"
+
+# (this is the default ex_aws config... if your keys are not in environment variables you can override it here)
+config :ex_aws,
+  access_key_id: [{:system, "AWS_ACCESS_KEY_ID"}, :instance_role],
+  secret_access_key: [{:system, "AWS_SECRET_ACCESS_KEY"}, :instance_role]
+```
+
+Read more about how ExAws manages configuration [here](https://github.com/CargoSense/ex_aws).
+
 ## v0.1.4 (11-10-2015)
   * (Enhancement: Local Storage) Filenames which contain path separators will flatten out as expected prior to moving copying the file to its destination.
 

README.md

@@ -14,20 +14,22 @@ Add the latest stable release to your `mix.exs` file:
 ```elixir
 defp deps do
   [
-    {:arc, "~> 0.1.4"}
+    arc: "~> 0.2.0",
+    ex_aws: "~> 0.4.10", # Required if using Amazon S3
+    httpoison: "~> 0.7"  # Required if using Amazon S3
   ]
 end
 ```
 
-and add `erlcloud` as an application startup dependency in your application's `mix.exs` file:
+If you plan on using Amazon's S3 Storage, you must also add `ex_aws` and `httpoison` the following applications as startup dependencies your application's `mix.exs` file:
 
 ```elixir
 def application do
   [
     mod: { MyApp, [] },
     applications: [
-      :other_app_dependencies,
-      :erlcloud
+      :ex_aws,
+      :httpoison
     ]
   ]
 end
@@ -153,17 +155,27 @@ end
 
 ### S3 Configuration
 
-[Erlcloud](https://github.com/gleber/erlcloud) is used to support Amazon S3.
+[ExAws](https://github.com/CargoSense/ex_aws) is used to support Amazon S3.
 
-To store your attachments in Amazon S3, you'll need to provide your AWS credentials and bucket destination in your application config:
+To store your attachments in Amazon S3, you'll need to provide a bucket destination in your application config:
 
 ```elixir
 config :arc,
-  access_key_id: "AKIAGJAVFNWDALJDLSA",
-  secret_access_key: "ncakAIWd+DaklwFAS51dDQo1i4EFAs\DASZGq",
   bucket: "uploads"
 ```
 
+In addition, ExAws must be configured with the appropriate Amazon S3 credentials.
+
+ExAws has by default the equivalent including the following in your mix.exs
+
+```elixir
+config :ex_aws,
+  access_key_id: [{:system, "AWS_ACCESS_KEY_ID"}, :instance_role],
+  secret_access_key: [{:system, "AWS_SECRET_ACCESS_KEY"}, :instance_role]
+```
+
+This means it will first look for the AWS standard AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables, and fall back using instance meta-data if those don't exist. You should set those environment variables to your credentials, or configure an instance that this library runs on to have an iam role.
+
 ### Storage Directory
 
 Arc requires the specification of a storage directory path (not including the bucket name).
@@ -278,6 +290,22 @@ Avatar.url(nil) #=> "http://example.com/images/placeholders/profile_image.png"
 Avatar.url({nil, scope}) #=> "http://example.com/images/placeholders/profile_image.png"
 ```
 
+**Virtual Host**
+
+To support AWS regions other than US Standard, it is convenient to generate urls in the [`virtual_host`](http://docs.aws.amazon.com/AmazonS3/latest/dev/VirtualHosting.html) style.  This will generate urls in the style: `https://#{bucket}.s3.amazonaws.com` instead of `https://s3.amazonaws.com/#{bucket}`.
+
+To use this style of url generation, your bucket name must be DNS compliant.
+
+This can be enabled with:
+
+```elixir
+config :arc,
+  virtual_host: true
+```
+
+> When using virtual hosted–style buckets with SSL, the SSL wild card certificate only matches buckets that do not contain periods. To work around this, use HTTP or write your own certificate verification logic.
+
+
 **Asset Host**
 
 You may optionally specify an asset host rather than using the default `bucket.s3.amazonaws.com` format.

lib/arc/storage/s3.ex

@@ -3,10 +3,10 @@ defmodule Arc.Storage.S3 do
 
   def put(definition, version, {file, scope}) do
     destination_dir = definition.storage_dir(version, {file, scope})
-    s3_key = Path.join(destination_dir, file.file_name) |> String.to_char_list
+    s3_key = Path.join(destination_dir, file.file_name)
     binary = File.read!(file.path)
     acl = definition.acl(version, {file, scope})
-    :erlcloud_s3.put_object(bucket, s3_key, binary, [acl: acl], erlcloud_config)
+    ExAws.S3.put_object(bucket, s3_key, binary, [acl: acl])
     file.file_name
   end
 
@@ -19,8 +19,8 @@ defmodule Arc.Storage.S3 do
 
   def delete(definition, version, {file, scope}) do
     destination_dir = definition.storage_dir(version, {file, scope})
-    s3_key = Path.join(destination_dir, file.file_name) |> String.to_char_list
-    :erlcloud_s3.delete_object(bucket, s3_key, erlcloud_config)
+    s3_key = Path.join(destination_dir, file.file_name)
+    ExAws.S3.delete_object(bucket, s3_key)
   end
 
   #
@@ -32,9 +32,9 @@ defmodule Arc.Storage.S3 do
   end
 
   defp build_signed_url(definition, version, file_and_scope, options) do
-    expire_in = Keyword.get(options, :expire_in, @default_expiry_time)
-    make_get_url(expire_in, bucket_name, s3_key(definition, version, file_and_scope), erlcloud_config)
-    |> Path.join("")
+    expires_in = Keyword.get(options, :expire_in, @default_expiry_time)
+    {:ok, url} = ExAws.S3.presigned_url(:get, bucket, s3_key(definition, version, file_and_scope), [expires_in: expires_in, virtual_host: virtual_host])
+    url
   end
 
   defp s3_key(definition, version, file_and_scope) do
@@ -45,31 +45,21 @@ defmodule Arc.Storage.S3 do
   end
 
   defp host do
-    Application.get_env(:arc, :asset_host) || "https://s3.amazonaws.com/#{bucket_name}"
+    Application.get_env(:arc, :asset_host) || default_host
   end
 
-  defp bucket_name do
-    Application.get_env(:arc, :bucket)
+  defp default_host do
+    case virtual_host do
+      true -> "https://#{bucket}.s3.amazonaws.com"
+      _    -> "https://s3.amazonaws.com/#{bucket}"
+    end
   end
 
-  defp erlcloud_config do
-    :erlcloud_s3.new(
-      to_char_list(Application.get_env(:arc, :access_key_id)),
-      to_char_list(Application.get_env(:arc, :secret_access_key)),
-      's3.amazonaws.com'
-    )
+  defp virtual_host do
+    Application.get_env(:arc, :virtual_host) || false
   end
 
   defp bucket do
-    bucket = Application.fetch_env!(:arc, :bucket)
-    to_char_list(bucket)
-  end
-
-  defp make_get_url(expire, bucket_name, s3_key, config) do
-    :erlcloud_s3.make_get_url(expire,
-      to_char_list(bucket_name),
-      to_char_list(s3_key),
-      config
-    )
+    Application.fetch_env!(:arc, :bucket)
   end
 end

mix.exs

@@ -1,7 +1,7 @@
 defmodule Arc.Mixfile do
   use Mix.Project
 
-  @version "0.1.4"
+  @version "0.2.0"
 
   def project do
     [app: :arc,
@@ -26,26 +26,16 @@ defmodule Arc.Mixfile do
      links: %{"GitHub" => "https://github.com/stavro/arc"},
      files: ~w(mix.exs README.md CHANGELOG.md lib)]
   end
-  # Configuration for the OTP application
-  #
-  # Type `mix help compile.app` for more information
+
   def application do
     [applications: [:logger]]
   end
 
-  # Dependencies can be Hex packages:
-  #
-  #   {:mydep, "~> 0.3.0"}
-  #
-  # Or git/path repositories:
-  #
-  #   {:mydep, git: "https://github.com/elixir-lang/mydep.git", tag: "0.1.0"}
-  #
-  # Type `mix help deps` for more examples and options
   defp deps do
     [
-      {:erlcloud, "~> 0.9.0"},
-      {:mock, "~> 0.1.1", only: :test}
+      {:ex_aws,    "~> 0.4.10", optional: true},
+      {:httpoison, "~> 0.7",    optional: true},
+      {:mock,      "~> 0.1.1",  only: :test}
     ]
   end
 end

mix.lock

@@ -1,6 +1,9 @@
-%{"erlcloud": {:hex, :erlcloud, "0.9.2"},
-  "jsx": {:hex, :jsx, "2.1.1"},
-  "lhttpc": {:hex, :lhttpc, "1.3.0"},
+%{"certifi": {:hex, :certifi, "0.3.0"},
+  "ex_aws": {:hex, :ex_aws, "0.4.13"},
+  "hackney": {:hex, :hackney, "1.4.7"},
+  "httpoison": {:hex, :httpoison, "0.8.0"},
+  "idna": {:hex, :idna, "1.0.2"},
   "meck": {:hex, :meck, "0.8.2"},
+  "mimerl": {:hex, :mimerl, "1.0.2"},
   "mock": {:hex, :mock, "0.1.1"},
-  "mogrify": {:hex, :mogrify, "0.1.0"}}
+  "ssl_verify_hostname": {:hex, :ssl_verify_hostname, "1.0.5"}}

test/storage/s3_test.exs

@@ -11,11 +11,26 @@ defmodule ArcTest.Storage.S3 do
     def acl(:private, _), do: :private
   end
 
+  def env_bucket do
+    System.get_env("ARC_TEST_BUCKET")
+  end
+
   setup_all do
-    :erlcloud.start
-    Application.put_env :arc, :bucket, System.get_env("ARC_TEST_BUCKET")
-    Application.put_env :arc, :access_key_id, System.get_env("ARC_TEST_S3_KEY")
-    Application.put_env :arc, :secret_access_key,  System.get_env("ARC_TEST_S3_SECRET")
+    Application.put_env :arc, :virtual_host, false
+    Application.put_env :arc, :bucket, env_bucket
+    # Application.put_env :ex_aws, :s3, [scheme: "https://", host: "s3.amazonaws.com", region: "us-west-2"]
+    Application.put_env :ex_aws, :access_key_id, System.get_env("ARC_TEST_S3_KEY")
+    Application.put_env :ex_aws, :secret_access_key,  System.get_env("ARC_TEST_S3_SECRET")
+  end
+
+  test "virtual_host" do
+    Application.put_env :arc, :virtual_host, false
+    url = Arc.Storage.S3.url(DummyDefinition, :original, {Arc.File.new(@img), nil})
+    assert "https://s3.amazonaws.com/#{env_bucket}/arctest/uploads/image.png", url
+
+    Application.put_env :arc, :virtual_host, false
+    url = Arc.Storage.S3.url(DummyDefinition, :original, {Arc.File.new(@img), nil})
+    assert "https://#{env_bucket}.s3.amazonaws.com/arctest/uploads/image.png", url
   end
 
   @tag :s3