Merge pull request #13505 from janek-warchol/patch-2

Explain how 'run_once' interacts with 'serial'
This commit is contained in:
Brian Coca 2015-12-12 00:29:37 -05:00
commit 14f3739260

View file

@ -182,13 +182,18 @@ This can be optionally paired with "delegate_to" to specify an individual host t
delegate_to: web01.example.org
When "run_once" is not used with "delegate_to" it will execute on the first host, as defined by inventory,
in the group(s) of hosts targeted by the play. e.g. webservers[0] if the play targeted "hosts: webservers".
in the group(s) of hosts targeted by the play - e.g. webservers[0] if the play targeted "hosts: webservers".
This approach is similar, although more concise and cleaner than applying a conditional to a task such as::
This approach is similar to applying a conditional to a task such as::
- command: /opt/application/upgrade_db.py
when: inventory_hostname == webservers[0]
.. note::
When used together with "serial", tasks marked as "run_once" will be ran on one host in *each* serial batch.
If it's crucial that the task is run only once regardless of "serial" mode, use
:code:`inventory_hostname == my_group_name[0]` construct.
.. _local_playbooks:
Local Playbooks