按键存在过滤Jinja列表

Question

我在Jinja写了一个Ansible模板,它有以下模式:

# Inventory
[Group1]
vm1 cluster=clusterName

[Group2]
vm2

请注意,第二个组没有cluster定义属性.

# Task Definition
vars:
  potential_seeds: "{{groups.all | map('extract', hostvars) | groupby('cluster') | list}}"

当然,这会导致明显的错误:

"the field 'vars' has an invalid value, which appears to include a variable that is undefined. The error was: 'dict object' has no attribute 'cluster'

我需要以一种只对已cluster定义的字典进行分组的方式过滤列表.

Answer 1

你可以使用selectattr之前groupby:

groups.all | 
  map('extract', hostvars) |
  selectattr('cluster','defined') |
  groupby('cluster') |
  list

这将仅选择cluster在分组之前定义属性的元素.