Use variable with item in when condition in ansible task - ansible

Question

I'm using the below playbook to capture the vmware datacenter information, which is working fine without any issues:
---
- hosts: localhost
vars_files: 1credentials.yml
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenter
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when:
- item.name is defined
- item.name == datacenter
below is the output:
PLAY [localhost] *******************************************************************************************************************************************************
TASK [Gathering Facts] *************************************************************************************************************************************************
ok: [localhost]
TASK [Gather information about all datacenters] ************************************************************************************************************************
ok: [localhost]
TASK [debug] ***********************************************************************************************************************************************************
skipping: [localhost] => (item={'name': 'Datacenter-Test', 'moid': 'datacenter-1247', 'config_status': 'gray', 'overall_status': 'gray'})
ok: [localhost] => (item={'name': 'opendc-rookie', 'moid': 'datacenter-2', 'config_status': 'gray', 'overall_status': 'gray'}) => {
"msg": "opendc-rookie"
}
PLAY RECAP *************************************************************************************************************************************************************
localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
But when I try to use a var_prompt and ask for user input for the variable datacenter, as below:
---
- hosts: localhost
vars_files: 1credentials.yml
vars_prompt:
- name: datacenter
prompt: mention the datacenter name
private: no
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenter
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when:
- item.name is defined
- item.name == "datacenter"
It is skipping the debug task without substituting the datacenter variable's value which was the user's input in the when condition. Kindly suggest how can I incorporate the variable value with the when condition having item. Below is the output skipping the variable
mention the datacenter name: opendc-rookie
PLAY [localhost] *******************************************************************************************************************************************************
TASK [Gathering Facts] *************************************************************************************************************************************************
ok: [localhost]
TASK [Gather information about all datacenters] ************************************************************************************************************************
ok: [localhost]
TASK [debug] ***********************************************************************************************************************************************************
skipping: [localhost] => (item={'name': 'Datacenter-Test', 'moid': 'datacenter-1247', 'config_status': 'gray', 'overall_status': 'gray'})
skipping: [localhost] => (item={'name': 'opendc-rookie', 'moid': 'datacenter-2', 'config_status': 'gray', 'overall_status': 'gray'})
skipping: [localhost]
PLAY RECAP *************************************************************************************************************************************************************
localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0

Answer 1

i suggest you to rename your register value (same name than the prompt var)
- hosts: localhost
vars_files: 1credentials.yml
vars_prompt:
- name: datacenter
prompt: mention the datacenter name
private: no
tasks:
- name: Gather information about all datacenters
community.vmware.vmware_datacenter_info:
hostname: '{{ vcenter_hostname }}'
username: '{{ vcenter_username }}'
password: '{{ vcenter_password }}'
validate_certs: no
delegate_to: localhost
register: datacenterX
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenterX.datacenter_info }}"
when:
- item.name is defined
- item.name == datacenter

Answer 2

In the trace we can see that the debug task is iterating over 2 dict items with the keys (or property) name = "Datacenter-Test" and name = "opendc-rookie".
Since you have a condition on item.name == "datacenter", the condition will only be true for items having the property `name = "datacenter". Which is not what you want to achieve.
how can I add the list values "Datacenter-Test" and "opendc-rookie" as variable in the when condition
Here are two options to filter the list of datacenters in order to retain the two selected names.
"simple condition": use a simple or in the when condition.
"list condition": filter directly the list to iterate over the items defined in the list wanted_datacenters. This option works with an input ansible-playbook loop.yml --extra-vars='{"wanted_datacenters": ["opendc-rookie", "Datacenter-Test"]}'
- hosts: localhost
vars:
datacenter:
- name: opendc-rookie
- name: Datacenter-Test
wanted_datacenters:
- opendc-rookie
- Datacenter-Test
tasks:
- name: "simple condition"
debug:
msg: "{{ item.name }}"
loop: "{{ datacenter }}"
when: item.name == "Datacenter-Test" or item.name == "opendc-rookie"
- name: "list condition"
debug:
msg: "{{ item.name }}"
loop: "{{ datacenter|selectattr('name', 'in', wanted_datacenters)|list }}"

Answer 3

Use json_query. This filter doesn't fail when an attribute is missing. For example,
shell> cat pb.yml
- hosts: localhost
vars:
datacenter:
datacenter_info:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
- config_status: gray
moid: datacenter-2
name: opendc-rookie
overall_status: gray
tasks:
- debug:
msg: "{{ _item }}"
vars:
_item: "{{ datacenter.datacenter_info|json_query(_query) }}"
_query: '[?name == `{{ dc_name|d("") }}`]'
gives
shell> ansible-playbook pb.yml -e dc_name=Datacenter-Test
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] =>
msg:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
shell> ansible-playbook pb.yml
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] =>
msg: []
You can iterate the list. For example,
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info|json_query(_query) }}"
vars:
_query: '[?name == `{{ dc_name|d("") }}`]'
If you want to test the name is in a list create an intersect. For example,
shell> cat pb.yml
- hosts: localhost
vars:
datacenter:
datacenter_info:
- config_status: gray
moid: datacenter-1247
name: Datacenter-Test
overall_status: gray
- config_status: gray
moid: datacenter-2
name: opendc-rookie
overall_status: gray
names: "{{ datacenter.datacenter_info|json_query('[].name') }}"
dc_names: ''
names_selected: "{{ names|intersect(dc_names.split(',')) }}"
tasks:
- debug:
msg: "{{ item.name }}"
loop: "{{ datacenter.datacenter_info }}"
when: item.name|d('') in names_selected
gives
shell> ansible-playbook pb.yml -e dc_names=Datacenter-Test,opendc-rookie
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'}) =>
msg: Datacenter-Test
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'}) =>
msg: opendc-rookie
shell> ansible-playbook pb.yml -e dc_names=opendc-rookie
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'})
ok: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'}) =>
msg: opendc-rookie
shell> ansible-playbook
PLAY [localhost] *****************************************************************************
TASK [debug] *********************************************************************************
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-1247', 'name': 'Datacenter-Test', 'overall_status': 'gray'})
skipping: [localhost] => (item={'config_status': 'gray', 'moid': 'datacenter-2', 'name': 'opendc-rookie', 'overall_status': 'gray'})
skipping: [localhost]