[aws|storage] ensure connection uses correct scheme, host and port

Currently, the `:scheme`, `:host` and `:port` are determined in
`#request_params` and passed as request parameters. However, passing
these as request parameters does not override the URI used to establish
the connection, which is used by Excon for the underlying socket.
Excon now considers these to be invalid request parameters.

This patch defers establishing the connection until the proper URI is
known, while still allowing the `:persistent` option to work as long as
the URI doesn't change.

lib/fog/aws/storage.rb

@@ -184,9 +184,9 @@ module Fog
 
           if params[:scheme]
             scheme = params[:scheme]
-            port   = params[:port]
+            port   = params[:port] || DEFAULT_SCHEME_PORT[scheme]
           else
-            scheme = @scheme || DEFAULT_SCHEME
+            scheme = @scheme
             port   = @port
           end
           if DEFAULT_SCHEME_PORT[scheme] == port
@@ -225,7 +225,7 @@ module Fog
             :host         => host,
             :port         => port,
             :path         => path,
-            :headers      => headers,
+            :headers      => headers
           })
 
           #
@@ -418,12 +418,10 @@ module Fog
             @port       = options[:port]        || DEFAULT_SCHEME_PORT[@scheme]
             @path_style = options[:path_style]  || false
           end
-
-          @connection = Fog::Connection.new("#{@scheme}://#{@host}:#{@port}#{@path}", @persistent, @connection_options)
         end
 
         def reload
-          @connection.reset
+          @connection.reset if @connection
         end
 
         def signature(params, expires)
@@ -493,6 +491,20 @@ DATA
           @hmac = Fog::HMAC.new('sha1', @aws_secret_access_key)
         end
 
+        def connection(scheme, host, port)
+          uri = "#{scheme}://#{host}:#{port}"
+          if @persistent
+            unless uri == @connection_uri
+              @connection_uri = uri
+              reload
+              @connection = nil
+            end
+          else
+            @connection = nil
+          end
+          @connection ||= Fog::Connection.new(uri, @persistent, @connection_options)
+        end
+
         def request(params, &block)
           refresh_credentials_if_expired
 
@@ -502,7 +514,9 @@ DATA
           signature = signature(params, expires)
 
           params = request_params(params)
-          params.delete(:port) unless params[:port]
+          scheme = params.delete(:scheme)
+          host   = params.delete(:host)
+          port   = params.delete(:port) || DEFAULT_SCHEME_PORT[scheme]
 
           params[:headers]['Date'] = expires
           params[:headers]['Authorization'] = "AWS #{@aws_access_key_id}:#{signature}"
@@ -510,12 +524,12 @@ DATA
           original_params = params.dup
 
           begin
-            response = @connection.request(params, &block)
+            response = connection(scheme, host, port).request(params, &block)
           rescue Excon::Errors::TemporaryRedirect => error
             headers = (error.response.is_a?(Hash) ? error.response[:headers] : error.response.headers)
             uri = URI.parse(headers['Location'])
             Fog::Logger.warning("fog: followed redirect to #{uri.host}, connecting to the matching region will be more performant")
-            response = Fog::Connection.new("#{@scheme}://#{uri.host}:#{@port}", false, @connection_options).request(original_params, &block)
+            response = Fog::Connection.new("#{uri.scheme}://#{uri.host}:#{uri.port}", false, @connection_options).request(original_params, &block)
           end
 
           response