Here's the scenario:
Objective(s):
Have a conditional that checks if a target_server list element content matches the ansible_hostname (i.e. if the substring found in the target_servers list (from the users dict) matches, then we provision the user; additionally, off course, if the list provides the entire hostname, it should match and the users also be provisioned)
Here's the code:
---
- hosts: all
become: yes
vars:
users:
user1:
is_sudo: no
is_chrooted: yes
auth_method: hvault
sa_homedir: firstname1lastname1
state: present
target_servers:
- vmss
- ubuntu
user2:
is_sudo: no
is_chrooted: yes
auth_method: hvault
sa_homedir: firstname2lastname2
state: present
target_servers:
- vmss
- ubuntu18
tasks:
- debug:
msg: "{{ ansible_hostname }}"
- debug:
msg: "{{ item.value.target_servers }}"
loop: "{{ lookup('dict', users|default({})) }}"
# This is just to exemplify what I'm trying to achieve as it is not supposed to work
- debug:
msg: "ansible_hostname is in target_servers of {{ item.key }}"
loop: "{{ lookup('dict', users|default({})) }}"
when: ansible_hostname is match(item.value.target_servers)
Here's the output showing that the match string test cannot be applied to a list (as expected):
TASK [debug] ************************************************************************************************************************************************
ok: [ubuntu18] =>
msg: ubuntu18
TASK [debug] ************************************************************************************************************************************************
ok: [ubuntu18] => (item={'key': 'user1', 'value': {'is_sudo': False, 'is_chrooted': True, 'auth_method': 'hvault', 'sa_homedir': 'firstname1lastname1', 'state': 'present', 'target_servers': ['vmss', 'ubuntu']}}) =>
msg:
- vmss
- ubuntu
ok: [ubuntu18] => (item={'key': 'user2', 'value': {'is_sudo': False, 'is_chrooted': True, 'auth_method': 'hvault', 'sa_homedir': 'firstname2lastname2', 'state': 'present', 'target_servers': ['vmss', 'ubuntu18']}}) =>
msg:
- vmss
- ubuntu18
TASK [debug] ************************************************************************************************************************************************
fatal: [ubuntu18]: FAILED! =>
msg: |-
The conditional check 'ansible_hostname is match(item.value.target_servers)' failed. The error was: Unexpected templating type error occurred on ({% if ansible_hostname is match(item.value.target_servers) %} True {% else %} False {% endif %}): unhashable type: 'list'
The error appears to be in 'test-play-users-core.yml': line 32, column 5, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
- debug:
^ here
Already tried researching about selectattr, json_query and subelements but I currently lack the understanding on how to make them work to match a substring inside a dict attribute that is a list.
In the example above, by changing from is match() to in, exact hostnames work fine, but that is not the goal. I need to match both exact hostnames and sub-strings for these hostnames.
Any help on how to accomplish this or suggestions about alternate methods will be greatly appreciated.
The example here might work if I could find a way to run it against a list (target_servers) after having already looped through the entire dictionary (are nested loops possible?): https://docs.ansible.com/ansible/latest/user_guide/playbooks_tests.html#testing-strings
I guess I've just found what I needed: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/subelements_lookup.html
Will try and provide an update soon.
Update: yes, subelements work! Here's the code needed:
- name: test 1
debug:
msg: "{{ item.1 }} matches {{ ansible_hostname }}"
with_subelements:
- "{{ users }}"
- target_servers
when: >
ansible_hostname is match(item.1)
You can use the select filter to apply the in test to all the elements of your users' target_servers list.
This would be your debug task:
- debug:
msg: "hostname is in target_servers of {{ item.key }}"
loop: "{{ users | dict2items }}"
loop_control:
label: "{{ item.key }}"
when: >-
item.value.target_servers
| select('in', inventory_hostname)
| length > 0
Given the playbook:
- hosts: all
gather_facts: false
vars:
_hostname: ubuntu18
users:
user1:
target_servers:
- vmss
- ubuntu
user2:
target_servers:
- vmss
- ubuntu18
tasks:
- debug:
msg: "hostname is in target_servers of {{ item.key }}"
loop: "{{ users | dict2items }}"
loop_control:
label: "{{ item.key }}"
when: >-
item.value.target_servers
| select('in', inventory_hostname)
| length > 0
This yields:
ok: [ubuntu18] => (item=user1) =>
msg: hostname is in target_servers of user1
ok: [ubuntu18] => (item=user2) =>
msg: hostname is in target_servers of user2
Doing it with subelements instead:
- hosts: all
gather_facts: false
vars:
_hostname: ubuntu18
users:
user1:
target_servers:
- vmss
- ubuntu
user2:
target_servers:
- vmss
- ubuntu18
tasks:
- debug:
msg: "hostname is in target_servers of {{ item.0.key }}"
loop: "{{ users | dict2items | subelements('value.target_servers') }}"
loop_control:
label: "{{ item.0.key }}"
when: item.1 in inventory_hostname
Will yield:
skipping: [ubuntu18] => (item=user1)
ok: [ubuntu18] => (item=user1) =>
msg: hostname is in target_servers of user1
skipping: [ubuntu18] => (item=user2)
ok: [ubuntu18] => (item=user2) =>
msg: hostname is in target_servers of user2