@ -14,19 +14,23 @@ 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.
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.
Playbooks are currently writeable in YAML. Other formats (JSON?) may
be supported in the future.
EXAMPLE
-------
[literal]
---
- pattern: '*'
hosts: '/etc/ansible/hosts'
tasks:
@ -52,48 +56,52 @@ 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.
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/mytemplates/httpd.j2 to write the Apache config file on each host
Next, use a Jinja2 template locally residing at
/srv/mytemplates/httpd.j2 to write the Apache config file on each host
to the path /etc/httpd/conf, using the previous values.
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.
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.
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 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 "do" statement describes what the task is and what ansible
module to use to accomplish the task, along with any arguments. The first
line in the "do" is the name of the task -- this will appear in any log output.
For each task, a "do" statement describes what the task is and what
ansible module to use to accomplish the task, along with any
arguments. The first line in the "do" is the name of the task -- this
will appear in any log output.
The second line in each "do" is the module name followed by module arguments.
The second line in each "do" is the module name followed by module
arguments.
Most modules accept key=value format arguments.
Handlers are like tasks, but are conditionally executed. If a module reports
a 'change', it can choose to notify a handler by name. If notified, it will
run only for hosts that changed.
Handlers are like tasks, but are conditionally executed. If a module
reports a 'change', it can choose to notify a handler by name. If
notified, it will run only for hosts that changed.
FUTURE BEHAVIOR
---------------
What the playbook run does with a host when an error is detected is currently being refined
and is subject to change.
What the playbook run does with a host when an error is detected is
currently being refined and is subject to change.
AUTHOR
Tim Bielawa
12 years ago