# Checking whether nested variable is defined in the when statement **URL:** \ **Category:** Ansible Project\ **Created:** [December 16, 2019, 8:57am UTC](https://forum.ansible.com/t/checking-whether-nested-variable-is-defined-in-the-when-statement/31826 "2019-12-16T08:57:57Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Emmanuel\_Livingstone](https://avatars.discourse-cdn.com/v4/letter/e/5f8ce5/32.png) [@Emmanuel\_Livingstone](https://forum.ansible.com/u/Emmanuel_Livingstone)\ **Post date:** [December 16, 2019, 8:57am UTC](https://forum.ansible.com/t/checking-whether-nested-variable-is-defined-in-the-when-statement/31826/1 "2019-12-16T08:57:57Z")
Nested data structures can be accessed either by indexing using the key name or dot syntax with the key name - [https://docs.ansible.com/ansible/latest/user\_guide/playbooks\_variables.html#accessing-complex-variable-data](https://docs.ansible.com/ansible/latest/user_guide/playbooks_variables.html#accessing-complex-variable-data) But I’m not able to access nested data structure from variables in the when statement. Here is a minimal sample to demonstrate the issue > # cat play.yml > > - hosts: localhost > > vars: > > parent: > > child1: true > > tasks: > > - name: “Check if variable is defined” > > fail: > > msg: “mandatory variable {{ item }} not passed as extra args when invoking playbook” > > when: item not in vars > > loop: > > - parent > > - parent.child1 > > - parent.child2 Here is the sample output ansible-playbook play.yml (livingstone-dev/monitoring) > [WARNING]: No inventory was parsed, only implicit localhost is available > > [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match ‘all’ > > PLAY [localhost] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > TASK [Gathering Facts] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > ok: [localhost] > > TASK [Check if variable is defined] \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > skipping: [localhost] =\> (item=parent) > > failed: [localhost] (item=parent.child1) =\> {“ansible\_loop\_var”: “item”, “changed”: false, “item”: “parent.child1”, “msg”: “mandatory variable parent.child1 not passed as extra args when invoking playbook”} > > failed: [localhost] (item=parent.child2) =\> {“ansible\_loop\_var”: “item”, “changed”: false, “item”: “parent.child2”, “msg”: “mandatory variable parent.child2 not passed as extra args when invoking playbook”} > > PLAY RECAP \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* > > localhost : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0 Any idea how I can have nested variables in ansible when statements. ---
**Author:** ![vbotka](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/vbotka/32/359_2.png) [@vbotka](https://forum.ansible.com/u/vbotka)\ **Post date:** [December 16, 2019, 12:10pm UTC](https://forum.ansible.com/t/checking-whether-nested-variable-is-defined-in-the-when-statement/31826/2 "2019-12-16T12:10:24Z")
Hi Emmanuel, >   vars: >     parent: >       child1: true >   tasks: >   - name: "Check if variable is defined" >     fail: >       msg: "mandatory variable {{ item }} not passed as extra args" >     when: item not in vars >     loop: >     - parent >     - parent.child1 >     - parent.child2 > > skipping: [localhost] =\> (item=parent) > failed: [localhost] (item=parent.child1) =\> {"ansible\_loop\_var": "item", > "changed": false, "item": "parent.child1", "msg": "mandatory variable > parent.child1 not passed as extra args when invoking playbook"} 'json\_query' returns 'False' when the parameter is not defined. 'set\_fact' before the evaluation to register the variable with 'hostvars'. For example     - set\_fact:         parent: "{{ parent }}"     - fail:         msg: "mandatory variable {{ item }} not passed as extra args"       when: not hostvars[inventory\_hostname]|json\_query(item)       loop:         - parent         - parent.child1         - parent.child2 Cheers,   -vlado ---
**Author:** ![Emmanuel\_Livingstone](https://avatars.discourse-cdn.com/v4/letter/e/5f8ce5/32.png) [@Emmanuel\_Livingstone](https://forum.ansible.com/u/Emmanuel_Livingstone)\ **Post date:** [December 17, 2019, 3:49am UTC](https://forum.ansible.com/t/checking-whether-nested-variable-is-defined-in-the-when-statement/31826/3 "2019-12-17T03:49:04Z")
Thanks Vladimir. I’m sure your solution works. I’ve figured out a simpler solution. Just posting it here for reference - [https://stackoverflow.com/a/59367345/434678](https://stackoverflow.com/a/59367345/434678)