How-to Variable in Variable

[bonheu...@gmail.com]

Hi everyone

I'm new to Ansible and I'm trying to automate the generation of Cisco router configuration files.

For the same config template, I will have several hardware models and I'd like to keep the code simple.

#main.yml (roles tasks)

---
- name: Generate configuration files
  template: src=CE-base.j2 dest=/home/bonh/ansible/playbooks/configs/{{item.hostname}}.txt
  with_items: "{{ CE }}"

#main.yml (variable definition)

---

CE:
  - { hostname: NRT001, model: NRT4451 }
  - { hostname: NRT002, model: NRT2921 }

NRT4451:
  wan: GigabitEthernet0/0/1
  b2b: GigabitEthernet0/0/2
  lan: GigabitEthernet0/0/0


NRT2921:
  wan: GigabitEthernet0/1
  b2b: GigabitEthernet0/2
  lan: GigabitEthernet0/0

#CE-base.j2 (base template)

---
interface {{ [item.model].wan }}

The desired result is to have the following

#NRT001.txt
interface GigabitEthernet0/0/1

#NRT002.txt
interface GigabitEthernet0/1

However I'm getting an error.

failed: [NRT001] (item={u'model': u'NRT4451', u'hostname': u'NRT001'}) => {"failed": true, "item": {"hostname": "NRT001", "model": "NRT4451"}, "msg": "AnsibleUndefinedVariable: 'list object' has no attribute 'wan'"}

I'm not a hardcore devOps and still learning. 

I tried the approach "How do I access a variable name programmatically?" in http://docs.ansible.com/ansible/faq.html but no success.

I think that's because my item has not a 'wan' object.

Of course if I use interface {{ NRT4451.wan }} it works fine.

Can someone help? I'm hoping it's just a syntax mistake.

Thanks

Bonh

[Kai Stian Olstad]

> *failed: [NRT001] (item={u'model': u'NRT4451', u'hostname': u'NRT001'}) =>

> {"failed": true, "item": {"hostname": "NRT001", "model": "NRT4451"}, "msg":

> "AnsibleUndefinedVariable: 'list object' has no attribute 'wan'"}*

>
> I'm not a hardcore devOps and still learning.
> I tried the approach "How do I access a variable name programmatically?"
> in http://docs.ansible.com/ansible/faq.html but no success.
> I think that's because my item has not a 'wan' object.
>
> Of course if I use interface {{ NRT4451.wan }} it works fine.
>
> Can someone help? I'm hoping it's just a syntax mistake.

"How do I access a variable name programmatically" is the correct way to
do it
https://docs.ansible.com/ansible/faq.html#how-do-i-access-a-variable-name-programmatically

interface {{ hostvars[inventory_hostname][item.model]['wan'] }}


--
Kai Stian Olstad

[bonheu...@gmail.com]

Hi

Still have an error

failed: [NRT001] (item={u'model': u'NRT4451', u'hostname': u'NRT001'}) => {"failed": true, "item": {"hostname": "NRT001", "model": "NRT4451"}, "msg": "AnsibleUndefinedVariable: 'dict object' has no attribute u'NRT4451'"}

[Kai Stian Olstad]

On 29. okt. 2016 12:42, bonheu...@gmail.com wrote:
> Hi
>
> Still have an error
>

> *failed: [NRT001] (item={u'model': u'NRT4451', u'hostname': u'NRT001'}) =>
> {"failed": true, "item": {"hostname": "NRT001", "model": "NRT4451"}, "msg":

> "AnsibleUndefinedVariable: 'dict object' has no attribute u'NRT4451'"}*

Is your variable definition in the roles vars/main.yml, if so this
should work.

interface {{ vars[item.model]['wan'] }}

--
Kai Stian Olstad

[Vikas Kumar]

Have a look here.

[bonheu...@gmail.com]

interface {{ vars[item.model]['wan'] }} works like a charm. 

Thanks guys! really appreciate!

I was struggling to find the magic predefined variable name to point to vars/main.yml.

Where is that documented? I looked here and here