Ansible SSH forwarding doesn't seem to work with Vagrant

OK, strange question. I have SSH forwarding working with Vagrant. But I'm trying to get it working when using Ansible as a Vagrant provisioner.

I found out exactly what Ansible is executing, and tried it myself from the command line, sure enough, it fails there too.

[/common/picsolve-ansible/u12.04%]ssh -o HostName=127.0.0.1 \
 -o User=vagrant -o  Port=2222 -o UserKnownHostsFile=/dev/null \
 -o StrictHostKeyChecking=no -o PasswordAuthentication=no \
 -o IdentityFile=/Users/bryanhunt/.vagrant.d/insecure_private_key \
 -o IdentitiesOnly=yes -o LogLevel=FATAL \
 -o ForwardAgent=yes "/bin/sh  \
 -c 'git clone git@bitbucket.org:bryan_picsolve/poc_docker.git /home/vagrant/poc_docker' "
Permission denied (publickey,password).

But when I just run vagrant ssh the agent forwarding works correctly, and I can checkout R/W my github project.

[/common/picsolve-ansible/u12.04%]vagrant ssh
vagrant@vagrant-ubuntu-precise-64:~$ /bin/sh  -c 'git clone git@bitbucket.org:bryan_picsolve/poc_docker.git /home/vagrant/poc_docker'
Cloning into '/home/vagrant/poc_docker'...
remote: Counting objects: 18, done.
remote: Compressing objects: 100% (14/14), done.
remote: Total 18 (delta 4), reused 0 (delta 0)
Receiving objects: 100% (18/18), done.
Resolving deltas: 100% (4/4), done.
vagrant@vagrant-ubuntu-precise-64:~$

Has anyone got any idea how it is working?

Update:

By means of ps awux I determined the exact command being executed by Vagrant.

I replicated it and git checkout worked.

 ssh vagrant@127.0.0.1 -p 2222 \
  -o Compression=yes \
  -o StrictHostKeyChecking=no \
  -o LogLevel=FATAL \ 
  -o StrictHostKeyChecking=no \
  -o UserKnownHostsFile=/dev/null \
  -o IdentitiesOnly=yes \
  -i /Users/bryanhunt/.vagrant.d/insecure_private_key \
  -o ForwardAgent=yes \
  -o LogLevel=DEBUG \
   "/bin/sh  -c 'git clone git@bitbucket.org:bryan_picsolve/poc_docker.git /home/vagrant/poc_docker' "

As of ansible 1.5 (devel aa2d6e47f0) last updated 2014/03/24 14:23:18 (GMT +100) and Vagrant 1.5.1 this now works.

My Vagrant configuration contains the following:

config.vm.provision "ansible" do |ansible|
   ansible.playbook = "../playbooks/basho_bench.yml"
   ansible.sudo = true
   ansible.host_key_checking = false
   ansible.verbose =  'vvvv'
   ansible.extra_vars = { ansible_ssh_user: 'vagrant', 
                 ansible_connection: 'ssh',
                 ansible_ssh_args: '-o ForwardAgent=yes'}

It is also a good idea to explicitly disable sudo use. For example, when using the Ansible git module, I do this:

- name: checkout basho_bench repository 
  sudo: no
  action: git repo=git@github.com:basho/basho_bench.git dest=basho_bench

The key difference appears to be the UserKnownHostFile setting. Even with StrictHostKeyChecking turned off, ssh quietly disables certain features including agent forwarding when there is a conflicting entry in the known hosts file (these conflicts are common for vagrant since multiple VMs may have the same address at different times). It works for me if I point UserKnownHostFile to /dev/null:

config.vm.provision "ansible" do |ansible|
  ansible.playbook = "playbook.yml"

  ansible.raw_ssh_args = ['-o UserKnownHostsFile=/dev/null']
end

Here's a workaround:

Create an ansible.cfg file in the same directory as your Vagrantfile with the following lines:

[ssh_connection]
ssh_args = -o ControlMaster=auto -o ControlPersist=60s -o ForwardAgent=yes

I've found that I need to do two separate things (on Ubuntu 12.04) to get it working:

the -o ForwardAgent thing that @Lorin mentions
adding /etc/sudoers.d/01-make_SSH_AUTH_SOCK_AVAILABLE with these contents:
```
Defaults env_keep += "SSH_AUTH_SOCK"
```

I struggled with a very similar problem for a few hours. Vagrant 1.7.2 ansible 1.9.4

My symptoms:

failed: [vagrant1] => {"cmd": "/usr/bin/git ls-remote '' -h refs/heads/HEAD", "failed": true, "rc": 128}
stderr: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

msg: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

FATAL: all hosts have already failed -- aborting

SSH'ing into the guest, I found that my ssh-agent was forwarding as expected:

vagrant@vagrant-ubuntu-trusty-64:~$ ssh -T git@github.com
Hi baxline! You've successfully authenticated, but GitHub does not provide shell access.

However, from the host machine, I could not open the connection:

$ ansible web -a "ssh-add -L"
vagrant1 | FAILED | rc=2 >>
Could not open a connection to your authentication agent.

After confirming that my ansible.cfg file was set up, as @Lorin noted, and my Vagrantfile set config.ssh.forward_agent = true, I still came up short.

The solution was to delete all lines in my host's ~/.ssh/known_hosts file that were associated with my guest. For me, they were the lines that started with:

[127.0.0.1]:2201 ssh-rsa
[127.0.0.1]:2222 ssh-rsa
[127.0.01]:2222 ssh-rsa
[127.0.0.1]:2200 ssh-rsa

Note the third line has a funny ip address. I'm not certain, but I believe that line was the culprit. These lines are created as I destroy and create vagrant VMs.

You can simply add this line to your Vagrantfile to enable the ssh forwarding: