ubuntu@test:~$ ssh -T git@github.com
Hi gituser! You've successfully authenticated, but GitHub does not provide shell access.

failed: [xxx.xxxxx.com] => {"changed": true, "cmd": ["ssh", "-T", "git@github.com"], "delta": "0:00:00.585481", "end": "2014-06-09 14:11:37.410907", "rc": 255, "start": "2014-06-09 14:11:36.825426"}
stderr: Permission denied (publickey).

- hosts: webservers
  sudo: yes
  remote_user: ubuntu

  tasks:

  - name: Test that git ssh connection is working.
    command: ssh -T git@github.com

sudo: yes

/etc/sudoers:

     Defaults    env_keep += "SSH_AUTH_SOCK"

[ssh_connection]
ssh_args=-o ForwardAgent=yes

[ssh_connection]
ssh_args=-o ControlMaster=auto -o ControlPersist=60s -o ControlPath=/tmp/ansible-ssh-%h-%p-%r -o ForwardAgent=yes

become_flags: "-E"

Defaults    env_keep += "SSH_AUTH_SOCK"

- name: enable SSH forwarding for sudo
  lineinfile:
    dest: /etc/sudoers
    insertafter: '^#?s*Defaultss+env_keepb'
    line: 'Defaults    env_keep += "SSH_AUTH_SOCK"'

- name: Add ssh agent line to sudoers
  lineinfile:
    dest: /etc/sudoers
    state: present
    regexp: SSH_AUTH_SOCK
    line: Defaults env_keep += "SSH_AUTH_SOCK"