ansible/docs/man/man5/ansible-playbook.5.asciidoc
2012-02-27 23:47:10 -05:00

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ansible-modules(5)
=================
:doctype:manpage
:man source: Ansible-playbook
:man version: 0.0.1
:man manual: System administration commands
NAME
----
ansible-playbook - format and function of an ansible playbook file
DESCRIPTION
-----------
Ansible ships with a ansible-playbook tool for running playbooks.
Playbooks can represent frequent tasks, desired system configurations,
or deployment processes.
FORMAT
------
Playbooks are currently writeable in YAML. Other formats (JSON?) may
be supported in the future.
EXAMPLE
-------
Remove the '# before pasting in the file, it's not part of the format and is only here to
make github render properly
[source]
- pattern: '*'
hosts: '/etc/ansible/hosts'
tasks:
- name: configure template & module variables for future template calls
action: setup http_port=80 max_clients=200
- name: write the apache config file
action: template src=/srv/templates/httpd.j2 dest=/etc/httpd/conf
notify:
- restart apache
- name: ensure apache is running
action: service name=httpd state=started
handlers:
- name: restart apache
- action: service name=httpd state=restarted
WHAT THE EXAMPLE MEANS
-----------------------
Here's what the above example will do.
For all hosts in /etc/ansible/hosts (one host per line) that are named
'webserver-anything', first write a JSON file into /etc/ansible/setup
on each remote system with the values max_clients and http_port.
Next, use a Jinja2 template locally residing at
/srv/templates/httpd.j2 to write the Apache config file on each host
to the path /etc/httpd/conf, using the previous values.
We'll ensure that apache is running if stopped.
If and only if the config file changed, note that we need to restart
apache at the end of the run, otherwise, don't bother because we
already know it is running.
HIGH LEVEL EXPLANATION
----------------------
Playbooks are executed top down and can contain multiple references to
patterns. For instance, a playbook could do something to all
webservers, then do something to all database servers, then do
something different to all webservers again.
For each pattern, the tasks in the 'tasks' list are executed in order
for all hosts in the host file matching the pattern.
For each task, a name/action pair describes what the task is and what
ansible module to use to accomplish the task, along with any
arguments. Additional fields like 'comment:' can be added and will
be ignored, so feel free to take notes in the file.
Most modules accept key=value format arguments.
Handlers are like tasks, but are conditionally executed. If a module
reports a 'change', it can notify one or more handler by name. If
notified, it will run only for hosts that changed.
ERROR HANDLING
--------------
If a host has a failure, the host will be ignored for the remainder
of the playbook execution.
AUTHOR
------
Ansible was originally written by Michael DeHaan. See the AUTHORS file
for a complete list of contributors.
SEE ALSO
--------
*ansible*(1)
*ansible-playbook*(5) - pending
Ansible home page: <https://github.com/mpdehaan/ansible/>