WordPress keeps asking for connection information in localhost

Parts of WordPress use (s)FTP to transfer files. Updates, for example, use (s)FTP. Media uploads do not, at least not unless something has changed in 3.7. If you are connecting to an (s)FTP server you have to provide the credentials that that server needs. Your file permissions won’t come into play until after that connection is made.

There are constants that you can define that should make this easier to manage. From the Codex:

define( 'FS_METHOD',       'ftpext' );
define( 'FTP_BASE',        '/path/to/wordpress/' );
define( 'FTP_CONTENT_DIR', '/path/to/wordpress/wp-content/' );
define( 'FTP_PLUGIN_DIR ', '/path/to/wordpress/wp-content/plugins/' );
define( 'FTP_PUBKEY',      '/home/username/.ssh/id_rsa.pub' );
define( 'FTP_PRIKEY',      '/home/username/.ssh/id_rsa' );
define( 'FTP_USER',        'username' );
define( 'FTP_PASS',        'password' );
define( 'FTP_HOST',        'ftp.example.org' );
define( 'FTP_SSL',         false );