Ansible: sudo without password

It's not ansible it's your server's configuration. Make sure that sudo is allowed for the user ansible is using without password.

1. To do that login to the server
2. Open the sudoers file with sudo visudo
3. Make sure you have a line something like this: centos ALL=(ALL) NOPASSWD:ALL
4. Replace centos with the your user
5. Save the file

You can try from the server itself by running:

sudo -u [yourusername] sudo echo "success"

If this works it should work from ansible too.

By default ansible runs sudo with the flags: -H -S -n to become root. Where --non-interactive would be the corresponding long form for option -n. This option seems to make sudo return the error message, without attempting to let the authentication modules do their thing.

I managed to get around the password error by creating a ~/.ansible.cfg containing lines as below, for the most relevant ansible version.

ansible 2.4

[defaults]
sudo_flags = --set-home --stdin

ansible 2.9

[sudo_become_plugin]
flags = -H -S

That was at least enough to allow pam_ssh_agent_auth.so to run and authenticate me.

Prior to version 2.8 the above example works, newer than 2.8 requires the second example. Documentation for the new style configuration can be found in the Ansible User Guide.