Double iteration in Ansible - ansible

Question

How can I iterate by list of dictionaries and assign each list from key of dictionary to with_items and iterate by this list: For example:
- name: "Deploy"
template:
src: "myfile"
dst: "{{ item }}/myfile" //"item" is "mypath1", "mypath2"..
with_items: {{ item.paths }}
loop:
- {group: "mygroup1", paths: ["mypath1", "mypath2"]}
- {group: "mygroup2", paths: ["mypath3", "mypath4"]}
when: "{{ item.group }} in group_names"

Answer 1

Use with_subelements. For example, given the inventory
shell> cat hosts
[mygroup1]
srv1
[mygroup2]
srv2
The playbook
shell> cat pb1.yml
- hosts: srv1,srv2
tasks:
- name: Deploy
debug:
msg: "{{ inventory_hostname }}: Create myfile at {{ item.1 }}/myfile"
with_subelements:
- "{{ _list }}"
- paths
when: item.0.group in group_names
vars:
_list:
- {group: mygroup1, paths: [mypath1, mypath2]}
- {group: mygroup2, paths: [mypath3, mypath4]}
gives
msg: 'srv1: Create myfile at mypath1/myfile'
msg: 'srv1: Create myfile at mypath2/myfile'
msg: 'srv2: Create myfile at mypath3/myfile'
msg: 'srv2: Create myfile at mypath4/myfile'
You'll be better off with a dictionary, instead of a list. For example, the playbook below gives the same results using a simple loop
shell> cat pb2.yml
- hosts: srv1,srv2
tasks:
- name: Deploy
debug:
msg: "{{ inventory_hostname }}: Create myfile at {{ item }}/myfile"
loop: "{{ group_names|map('extract', _dict)|flatten }}"
vars:
_dict:
mygroup1: [mypath1, mypath2]
mygroup2: [mypath3, mypath4]
But, the Ansible-way would be to put the data into the group_vars. For example
shell> cat group_vars/mygroup1.yml
my_paths: [mypath1, mypath2]
shell> cat group_vars/mygroup2.yml
my_paths: [mypath3, mypath4]
and the simple playbook below give the same results
shell> cat pb3.yml
- hosts: srv1,srv2
tasks:
- name: Deploy
debug:
msg: "{{ inventory_hostname }}: Create myfile at {{ item }}/myfile"
loop: "{{ my_paths }}"