当条件没有被jinja2格式包装时，可以忽略。

The following task is running regardless of whatever i set as the ansible_distribution.

下面的任务是运行，不管我设置为ansible_distribution。

- name: install packages
  yum: name={{item.name}} state=installed
  when: item.when
  with_items:
  - { name: 'telnet', when: "ansible_distribution == 'CentOS'" }
  - { name: 'net-tools', when: "ansible_distribution == 'Debian'" }
  - { name: 'net-tools', when: "ansible_distribution == 'blahblahblah'" }

Result

结果

TASK [Gathering Facts] ***************************************************************************************************************************************************************************************
 ok: [172.16.2.3]

TASK [test : install packages] *********************************************************************************************************************************************************************************
ok: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'CentOS'", u'name': u'telnet'})
ok: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'Debian'", u'name': u'net-tools'})
ok: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'blahblahblah'", u'name': u'httpd'})

Here is my ansible version

这是我的一个可以解释的版本。

ansible 2.3.0.0
 config file = /etc/ansible/ansible.cfg
 configured module search path = Default w/o overrides
 python version = 2.7.5 (default, Nov  6 2016, 00:28:07) [GCC 4.8.520150623 (Red Hat 4.8.5-11)]

However when wrap the when condition in jinja2 format like so "{{item.when}}", i get following albeit with a warning.

然而，当用jinja2格式包装时，就像这样“{{item。“当}”时，我得到了警告。

TASK [test : install packages] *********************************************************************************************************************************************************************************
[WARNING]: when statements should not include jinja2 templating delimiters such as {{ }} or {% %}. Found: {{item.when}}

skipping: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'blahblahblah'", u'name': u'httpd'})
skipping: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'Debian'", u'name': u'net-tools'})
ok: [172.16.2.3] => (item={u'when': u"ansible_distribution == 'CentOS'", u'name': u'telnet'})

Any idea how i can rewrite this task without having to wrap the when condition in a jinja2 format?

我是否知道如何重写这个任务，而不必在jinja2格式中使用when条件?

1 个解决方案

#1

You can try this:

你可以试试这个:

- name: install packages
  package:
    name: "{{ pkgs[ansible_distribution] | default(pkgs.default) }}"
    state: present
  vars:
    pkgs:
      CentOS: telnet
      Debian: net-tools
      default: net-tools

I replaced yum module with package to make it distro independent, because yum will definitely fail on Debian.

我用包替换了yum模块，使它独立，因为yum肯定会在Debian上失败。

I agree with @techraf's comment that if you have a lot of tasks that are different for each distro, consider using include/include_vars and with_first_found to include distro-specific set of tasks/variables (see example).

我同意@techraf的评论，如果您有许多不同的任务，对于每个发行版，可以考虑使用include/include_vars和with_first_found来包含特定于distr的任务/变量集(参见示例)。

#1