Add support for source_profile and role_arn

aws-sdk-core/lib/aws-sdk-core/shared_credentials.rb

@@ -36,7 +36,13 @@ def initialize(options = {})
     attr_reader :profile_name
 
     # @return [Credentials]
-    attr_reader :credentials
+    def credentials
+      if @credentials.respond_to?(:credentials)
+        @credentials.credentials
+      else
+        @credentials
+      end
+    end
 
     # @api private
     def inspect
@@ -67,18 +73,34 @@ def default_path
 
     def load_from_path
       profile = load_profile
-      @credentials = Credentials.new(
+      credentials = Credentials.new(
         profile['aws_access_key_id'],
         profile['aws_secret_access_key'],
         profile['aws_session_token']
       )
+      @credentials = if profile['role_arn']
+                        AssumeRoleCredentials.new(
+                          role_arn: profile['role_arn'],
+                          role_session_name: profile_name,
+                          credentials: credentials
+                        )
+                      else credentials
+                      end
     end
 
     def load_profile
-      if profile = profiles[profile_name]
+      profile = load_named_profile(profile_name)
+      if profile['source_profile']
+        profile = load_named_profile(profile['source_profile']).merge(profile)
+      end
+      profile
+    end
+
+    def load_named_profile(name)
+      if profile = profiles[name]
         profile
       else
-        msg = "Profile `#{profile_name}' not found in #{path}"
+        msg = "Profile `#{name}' not found in #{path}"
         raise Errors::NoSuchProfileError, msg
       end
     end

aws-sdk-core/spec/aws/shared_credentials_spec.rb

@@ -44,6 +44,14 @@ module Aws
       expect(creds.session_token).to eq('TOKEN_1')
     end
 
+    it 'supports fetching a source_profile' do
+      stub_const('ENV', { 'AWS_PROFILE' => 'childprofile' })
+      creds = SharedCredentials.new(path:mock_credential_file).credentials
+      expect(creds.access_key_id).to eq('ACCESS_KEY_1')
+      expect(creds.secret_access_key).to eq('SECRET_KEY_1')
+      expect(creds.session_token).to eq('TOKEN_3')
+    end
+
     it 'raises when a profile does not exist' do
       msg = /^Profile `bazprofile' not found in .+mock_shared_credentials/
       expect {

aws-sdk-core/spec/fixtures/credentials/mock_shared_credentials

@@ -12,3 +12,7 @@ aws_session_token = TOKEN_1
 aws_access_key_id = ACCESS_KEY_2
 aws_secret_access_key = SECRET_KEY_2
 aws_session_token = TOKEN_2
+
+[childprofile]
+source_profile = fooprofile
+aws_session_token = TOKEN_3