Minor fixess (#186)

* better config interface

* fix issue with instance auth

Author: benwilson512

lib/ex_aws.ex

@@ -26,7 +26,7 @@ defmodule ExAws do
   @spec request(ExAws.Operation.t) :: term
   @spec request(ExAws.Operation.t, Keyword.t) :: {:ok, term} | {:error, term}
   def request(op, config_overrides \\ []) do
-    ExAws.Operation.perform(op, ExAws.Config.build(op.service, config_overrides))
+    ExAws.Operation.perform(op, ExAws.Config.new(op.service, config_overrides))
   end
 
   @doc """
@@ -35,7 +35,7 @@ defmodule ExAws do
   @spec stream!(ExAws.Operation.t) :: Enumerable.t
   @spec stream!(ExAws.Operation.t, Keyword.t) :: Enumerable.t
   def stream!(op, config_overrides \\ []) do
-    ExAws.Operation.stream!(op, ExAws.Config.build(op.service, config_overrides))
+    ExAws.Operation.stream!(op, ExAws.Config.new(op.service, config_overrides))
   end
 
   @doc """

lib/ex_aws/config.ex

@@ -12,15 +12,6 @@ defmodule ExAws.Config do
     :region, :security_token
   ]
 
-  def build(service, opts \\ []) do
-    overrides = Map.new(opts)
-
-    service
-    |> ExAws.Config.get(overrides)
-    |> retrieve_runtime_config
-    |> parse_host_for_region
-  end
-
   @doc """
   Builds a complete set of config for an operation.
 
@@ -29,7 +20,16 @@ defmodule ExAws.Config do
   3) Keys set on the individual service e.g `config :ex_aws, :s3` are merged in
   4) Finally, any configuration overrides are merged in
   """
-  def get(service, overrides) do
+  def new(service, opts \\ []) do
+    overrides = Map.new(opts)
+
+    service
+    |> build_base(overrides)
+    |> retrieve_runtime_config
+    |> parse_host_for_region
+  end
+
+  def build_base(service, overrides \\ %{}) do
     defaults = ExAws.Config.Defaults.get(service)
     common_config = Application.get_all_env(:ex_aws) |> Map.new |> Map.take(@common_config)
     service_config = Application.get_env(:ex_aws, service, []) |> Map.new

test/lib/ex_aws/config_test.exs

@@ -5,15 +5,15 @@ defmodule ExAws.ConfigTest do
     value = "foo"
     System.put_env("ExAwsConfigTest", value)
     assert :s3
-    |> ExAws.Config.build([access_key_id: {:system, "ExAwsConfigTest"}])
+    |> ExAws.Config.new([access_key_id: {:system, "ExAwsConfigTest"}])
     |> Map.get(:access_key_id) == value
   end
 
   test "security_token is configured properly" do
     value = "security_token"
     System.put_env("AWS_SECURITY_TOKEN", value)
     assert :s3
-    |> ExAws.Config.build([access_key_id: {:system, "AWS_SECURITY_TOKEN"}, security_token: {:system, "AWS_SECURITY_TOKEN"}])
+    |> ExAws.Config.new([access_key_id: {:system, "AWS_SECURITY_TOKEN"}, security_token: {:system, "AWS_SECURITY_TOKEN"}])
     |> Map.get(:security_token) == value
   end
 end

test/lib/ex_aws/s3_test.exs

@@ -144,5 +144,5 @@ defmodule ExAws.S3Test do
       List.keyfind(headers, "X-Amz-Expires", 0)
   end
 
-  defp config(), do: ExAws.Config.build(:s3, [])
+  defp config(), do: ExAws.Config.new(:s3, [])
 end