Ansible - 在列表产品上循环时枚举列表(嵌套循环) [英] Ansible - Enumerate list when looping on list product (nested loop)
问题描述
我在 Ansible 中使用嵌套循环(为 10 个用户中的每一个创建 3 个虚拟机"):
I am using a nested loop in Ansible ("create 3 VMs for each of the 10 users"):
- name: Add hosts to inventory
add_host:
name: "{{ '%s-%02d-%02d' | format(vm_prefix, item.0, item.1.number) }}"
groups: vms
loop: "{{userlist | product(vms_per_user) | list }}"
我的问题是 - 我有没有办法获取第二个列表中项目的索引?
My question is - do I have any way of getting the index of an item in the second list?
- name: Add hosts to inventory
add_host:
name: "{{ '%s-%02d-%02d' | format(vm_prefix, item.0, item.1.number) }}"
groups: vms
vm_index: "{{ get the index of this particular VM in vms_per_user }}"
loop: "{{userlist | product(vms_per_user) | list }}"
我知道 with_indexed_items 和 flatten + loop_control.index，但我不知道如何编写它，以便我将获得一个仅在第二个列表上循环的索引，并且每次从 0 重新开始新用户(第一个列表中的每个新元素).
I know about with_indexed_items and flatten + loop_control.index, but I cannot figure out how to write this so that I will get an index that loops only on the second list, and restarts from 0 for every new user (every new element in the first list).
TL;DR - 我正在寻找这个 Python 结构的 ansible 等价物:
TL;DR - I am looking for the ansible equivalent of this Python construct:
for user in users:
for (index, vm_name) in enumerate(vms_per_user):
do_something_with user, index, vm_name
谢谢！
推荐答案
如果 Ansible 有一个 enumerate 过滤器，这将非常容易.它没有，但我们可以给它一个.我将以下内容放入filter_plugins/enumerate.py:
If Ansible had an enumerate filter this would be pretty easy. It doesn't, but we can give it one. I put the following content into filter_plugins/enumerate.py:
#!/usr/bin/python
def filter_enumerate(v):
return list(enumerate(v))
class FilterModule (object):
def filters(self):
return {
'enumerate': filter_enumerate,
}
对于列表[a, b, c]，这将返回一个新列表[[0,a], [1,b], [2,c]].我们可以像这样在您的剧本中使用它:
For a list [a, b, c], this will return a new list [[0,a], [1,b], [2,c]]. We can use that in your playbook like this:
---
- hosts: localhost
gather_facts: false
vars:
userlist:
- alice
- bob
- mallory
vms_per_user:
- vm1
- vm2
- vm3
vm_prefix: foo-
tasks:
- debug:
msg:
add_host:
name: "{{ vm_prefix }}{{ item.0 }}-{{ item.1.1 }}"
groups: vms
vm_index: "{{ item.1.0 }}"
loop: "{{ userlist | product(vms_per_user|enumerate) | list }}"
此调试任务的输出将类似于:
The output of this debug task will look something like:
ok: [localhost] => (item=[u'alice', [0, u'vm1']]) => {
"msg": {
"add_host": {
"groups": "vms",
"name": "foo-alice-vm1",
"vm_index": "0"
}
}
}
ok: [localhost] => (item=[u'alice', [1, u'vm2']]) => {
"msg": {
"add_host": {
"groups": "vms",
"name": "foo-alice-vm2",
"vm_index": "1"
}
}
}
ok: [localhost] => (item=[u'alice', [2, u'vm3']]) => {
"msg": {
"add_host": {
"groups": "vms",
"name": "foo-alice-vm3",
"vm_index": "2"
}
}
}
等
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