mirror of https://github.com/ansible/ansible.git
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
117 lines
4.4 KiB
ReStructuredText
117 lines
4.4 KiB
ReStructuredText
.. _connections:
|
|
|
|
******************************
|
|
Connection methods and details
|
|
******************************
|
|
|
|
This section shows you how to expand and refine the connection methods Ansible uses for your inventory.
|
|
|
|
ControlPersist and paramiko
|
|
---------------------------
|
|
|
|
By default, Ansible uses native OpenSSH, because it supports ControlPersist (a performance feature), Kerberos, and options in ``~/.ssh/config`` such as Jump Host setup. If your control machine uses an older version of OpenSSH that does not support ControlPersist, Ansible will fallback to a Python implementation of OpenSSH called 'paramiko'.
|
|
|
|
.. _connection_set_user:
|
|
|
|
Setting a remote user
|
|
---------------------
|
|
|
|
By default, Ansible connects to all remote devices with the user name you are using on the control node. If that user name does not exist on a remote device, you can set a different user name for the connection. If you just need to do some tasks as a different user, look at :ref:`become`. You can set the connection user in a playbook:
|
|
|
|
.. code-block:: yaml
|
|
|
|
---
|
|
- name: update webservers
|
|
hosts: webservers
|
|
remote_user: admin
|
|
|
|
tasks:
|
|
- name: thing to do first in this playbook
|
|
. . .
|
|
|
|
as a host variable in inventory:
|
|
|
|
.. code-block:: text
|
|
|
|
other1.example.com ansible_connection=ssh ansible_user=myuser
|
|
other2.example.com ansible_connection=ssh ansible_user=myotheruser
|
|
|
|
or as a group variable in inventory:
|
|
|
|
.. code-block:: yaml
|
|
|
|
cloud:
|
|
hosts:
|
|
cloud1: my_backup.cloud.com
|
|
cloud2: my_backup2.cloud.com
|
|
vars:
|
|
ansible_user: admin
|
|
|
|
Setting up SSH keys
|
|
-------------------
|
|
|
|
By default, Ansible assumes you are using SSH keys to connect to remote machines. SSH keys are encouraged, but you can use password authentication if needed with the ``--ask-pass`` option. If you need to provide a password for :ref:`privilege escalation <become>` (sudo, pbrun, and so on), use ``--ask-become-pass``.
|
|
|
|
.. include:: shared_snippets/SSH_password_prompt.txt
|
|
|
|
To set up SSH agent to avoid retyping passwords, you can do:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ ssh-agent bash
|
|
$ ssh-add ~/.ssh/id_rsa
|
|
|
|
Depending on your setup, you may wish to use Ansible's ``--private-key`` command line option to specify a pem file instead. You can also add the private key file:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ ssh-agent bash
|
|
$ ssh-add ~/.ssh/keypair.pem
|
|
|
|
Another way to add private key files without using ssh-agent is using ``ansible_ssh_private_key_file`` in an inventory file as explained here: :ref:`intro_inventory`.
|
|
|
|
Running against localhost
|
|
-------------------------
|
|
|
|
You can run commands against the control node by using "localhost" or "127.0.0.1" for the server name:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ ansible localhost -m ping -e 'ansible_python_interpreter="/usr/bin/env python"'
|
|
|
|
You can specify localhost explicitly by adding this to your inventory file:
|
|
|
|
.. code-block:: bash
|
|
|
|
localhost ansible_connection=local ansible_python_interpreter="/usr/bin/env python"
|
|
|
|
.. _host_key_checking_on:
|
|
|
|
Managing host key checking
|
|
--------------------------
|
|
|
|
Ansible enables host key checking by default. Checking host keys guards against server spoofing and man-in-the-middle attacks, but it does require some maintenance.
|
|
|
|
If a host is reinstalled and has a different key in 'known_hosts', this will result in an error message until corrected. If a new host is not in 'known_hosts' your control node may prompt for confirmation of the key, which results in an interactive experience if using Ansible, from say, cron. You might not want this.
|
|
|
|
If you understand the implications and wish to disable this behavior, you can do so by editing ``/etc/ansible/ansible.cfg`` or ``~/.ansible.cfg``:
|
|
|
|
.. code-block:: text
|
|
|
|
[defaults]
|
|
host_key_checking = False
|
|
|
|
Alternatively this can be set by the :envvar:`ANSIBLE_HOST_KEY_CHECKING` environment variable:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ export ANSIBLE_HOST_KEY_CHECKING=False
|
|
|
|
Also note that host key checking in paramiko mode is reasonably slow, therefore switching to 'ssh' is also recommended when using this feature.
|
|
|
|
Other connection methods
|
|
------------------------
|
|
|
|
Ansible can use a variety of connection methods beyond SSH. You can select any connection plugin, including managing things locally and managing chroot, lxc, and jail containers.
|
|
A mode called 'ansible-pull' can also invert the system and have systems 'phone home' via scheduled git checkouts to pull configuration directives from a central repository.
|