The synchronize module of Ansible (v1.6.5) prompts for the passphrase (Enter passphrase for key) even though I already entered it at the beginning of running th
I think by default synchronize is explicitly setting a username on the rsync command - you can prevent this and allow rsync to work from your ssh config file.
http://docs.ansible.com/synchronize_module.html
set_remote_user
put user@ for the remote paths. If you have a custom ssh config to define the remote user for a host that does not match the inventory user, you should set this parameter to "no".
I have a remote user configured in my ssh config and needed to add set_remote_user=no
to get synchronize to work, otherwise it tried to use the wrong username and neither ssh key nor password would work.