# Searching for eficient way to check group of variables **URL:** \ **Category:** Ansible Project\ **Created:** [July 5, 2013, 6:56am UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071 "2013-07-05T06:56:00Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![David\_Karban](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@David\_Karban](https://forum.ansible.com/u/David_Karban)\ **Post date:** [July 5, 2013, 6:56am UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/1 "2013-07-05T06:56:00Z")
Hello, I recently wrote role, that set up an openvz on centos host, including network configuration. For that purpose, I have variables ip, gateway, netmask, dns1 and dns2 in host\_vars/. Variables are mandatory, I cannot set up networking withnout them, so I`m checking them out. So far I have this code: ```auto - fail: msg="You need to define ip, gateway, netmask, dns1 and dns2 in hosts_vars" when: ip is not defined - fail: msg="You need to define ip, gateway, netmask, dns1 and dns2 in hosts_vars" when: gateway is not defined - fail: msg="You need to define ip, gateway, netmask, dns1 and dns2 in hosts_vars" when: netmask is not defined - fail: msg="You need to define ip, gateway, netmask, dns1 and dns2 in hosts_vars" when: dns1 is not defined - fail: msg="You need to define ip, gateway, netmask, dns1 and dns2 in hosts_vars" when: dns2 is not defined ``` Somehow I think, I`m pretty sure, I`m missing some nicer way how to do it, is it possible to have it in one fail statement? Regards David Karban ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [July 5, 2013, 2:02pm UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/2 "2013-07-05T14:02:20Z")
In the latest 1.3, you can use the variable in a template like this: {{ foo | mandatory }} This will yell when you try to use the variable that is undefined. You can also globally turn on “all variables must be defined” warnings in ansible.cfg (see examples/ansible.cfg in the checkout) ---
**Author:** ![David\_Karban](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@David\_Karban](https://forum.ansible.com/u/David_Karban)\ **Post date:** [July 5, 2013, 2:53pm UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/3 "2013-07-05T14:53:25Z")
Thanks, I will try it out! Dne 5.7.2013 16:02 “Michael DeHaan” \<[michael@ansibleworks.com](mailto:michael@ansibleworks.com)\> napsal(a): ---
**Author:** ![David\_Golden](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@David\_Golden](https://forum.ansible.com/u/David_Golden)\ **Post date:** [July 5, 2013, 6:15pm UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/4 "2013-07-05T18:15:40Z")
My approach: (1) I use a single role variable that contains keys/value. E.g. for the "webapp" role, I call it "webapp\_args". (2) Any globally defined variables (e.g. from host\_vars), I copy into a slot in webapp\_args on each role invocation (3) In the role, I check that webapp\_args is defined (4) In the role, I loop over mandatory items that must exist: Example: - name: Assert webapp\_args   fail: msg="required webapp\_args parameters must be provided"   when: webapp\_args is not defined - name: Assert required webapp\_args parameters   fail: msg="required webapp\_args[{{item}}] must be provided"   when: webapp\_args[item] is not defined   with\_items:     - app\_name     - app\_path     - app\_port     - ... I hope someday there's a way to do that more automatically in the way that roles work, but for now it's working fine for me. You could probably do it with globals instead of a role argument structure, but I personally dislike using globals in that way, so I didn't do that myself. -- David ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [July 5, 2013, 6:20pm UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/5 "2013-07-05T18:20:47Z")
Also: - fail: msg=variables not defined when: foo is not defined or bar is not defined or baz is not defined should be valid. ---
**Author:** ![David\_Karban](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@David\_Karban](https://forum.ansible.com/u/David_Karban)\ **Post date:** [July 8, 2013, 8:39am UTC](https://forum.ansible.com/t/searching-for-eficient-way-to-check-group-of-variables/13071/6 "2013-07-08T08:39:10Z")
> Also: > > - fail: msg=variables not defined >   when: foo is not defined or bar is not defined or baz is not defined Hi Michael, tested, works great, thanks !