Ansibleのwhenの条件指定、あまり得意ではない(あまり使わないから)ので思い付きでいろいろ試してみた！
trick or treat
まずは無邪気に書いてみる(失敗版)
---
- hosts: localhost
tasks:
- debug:
msg: Happy Halloween
when: trick or treat
[zaki@manager halloween]$ ansible-playbook playbook.yml -e trick=True -e treat=False
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
msg: Happy Halloween
PLAY RECAP *********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
お、動く…
と思ったんだけど、
[zaki@manager halloween]$ ansible-playbook playbook.yml -e trick=False -e treat=False
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
msg: Happy Halloween
PLAY RECAP *********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
trick:false and treat:falseでも動く。これじゃダメだ。
これがなぜダメなのかは時間があれば調べよう…
boolにキャスト
(キャストって言い方でいいんだっけ)
---
- hosts: localhost
tasks:
- debug:
msg: Happy Halloween
when: trick|bool or treat|bool
これだと
[zaki@manager halloween]$ ansible-playbook playbook.yml -e trick=False -e treat=False
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
skipping: [localhost]
PLAY RECAP *********************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0
[zaki@manager halloween]$
お、期待通り。
(true/true, false/true, true/falseも大丈夫)
定義済みチェック
ただしこのままだと、trickとtreatが定義済みでなければエラーになってしまう。
[zaki@manager halloween]$ ansible-playbook playbook.yml
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
fatal: [localhost]: FAILED! =>
msg: |-
The conditional check 'trick|bool or treat|bool' failed. The error was: error while evaluating conditional (trick|bool or treat|bool): 'trick' is undefined
The error appears to be in '/home/zaki/work/ansible/halloween/playbook.yml': line 4, column 5, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
tasks:
- debug:
^ here
PLAY RECAP *********************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
ので、definedを使って定義済みかどうかのチェックを入れてみる。
(もっとスマートに書ける方法はあるかもしれないけど、ひとまずこれで動いた、という内容)
---
- hosts: localhost
tasks:
- debug:
msg: Happy Halloween
when: (trick is defined and trick|bool) or (treat is defined and treat|bool)
結果
[zaki@manager halloween]$ ansible-playbook playbook.yml
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
skipping: [localhost]
PLAY RECAP *********************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0
未定義時はfalseと同等
[zaki@manager halloween]$
[zaki@manager halloween]$ ansible-playbook playbook.yml -e trick=True
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
msg: Happy Halloween
PLAY RECAP *********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
[zaki@manager halloween]$
[zaki@manager halloween]$ ansible-playbook playbook.yml -e treat=True
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [debug] *******************************************************************
ok: [localhost] =>
msg: Happy Halloween
PLAY RECAP *********************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
trickかtreatをTrueにすればOK
環境
[zaki@manager halloween]$ cat /etc/redhat-release
CentOS Linux release 7.7.1908 (Core)
[zaki@manager halloween]$
[zaki@manager halloween]$ ansible-playbook --version
ansible-playbook 2.8.5
config file = /home/zaki/work/ansible/halloween/ansible.cfg
configured module search path = [u'/home/zaki/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
ansible python module location = /usr/lib/python2.7/site-packages/ansible
executable location = /usr/bin/ansible-playbook
python version = 2.7.5 (default, Aug 7 2019, 00:51:29) [GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]
[zaki@manager halloween]$
[zaki@manager halloween]$ cat ansible.cfg
[defaults]
stdout_callback = yaml
[zaki@manager halloween]$
余談(cowsay)
本当は牛に「trick or treat」って言わせたかったんだけど…
[zaki@manager halloween]$ sudo yum install cowsay
...
[zaki@manager halloween]$ ansible-playbook playbook.yml -e trick=True
[WARNING]: provided hosts list is empty, only localhost is available. Note
that the implicit localhost does not match 'all'
__________________
< PLAY [localhost] >
------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
________________________
< TASK [Gathering Facts] >
------------------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
ok: [localhost]
______________
< TASK [debug] >
--------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
ok: [localhost] =>
msg: Happy Halloween
____________
< PLAY RECAP >
------------
\ ^__^
\ (oo)\_______
(__)\ )\/\
||----w |
|| ||
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
[zaki@manager halloween]$
違う、そうじゃない。