Set variable based on group_names

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1

Hi,

Perhaps it’s an easy question but I cannot find a way to answer it myself.

More in details – I have two groups in my inventory: clients (many hosts) and server (single host), and a template at the client which needs to use the server address. If it happens that a client host is also in the ‘server’ group, I wanted to set the address in the template to ‘localhost’. Otherwise, the address should point to the server address as specified in the inventory. I guess it’s quite easy to code it using jinja2 directly in the template but my template includes many places with such a reference, so I thought about first setting the server address variable, and then using this variable to evaluate the template. Is this correct way of thinking? How can I set a variable in a play before template evaluation? Otherwise, have you got any other ideas?

Cheers,
Jacek

2

Hi Jacek, this should work for you:

  • set_fact: address_variable=‘localhost’
    when: ‘server’ in group_names
  • set_fact: address_variable=‘server_address_here’
    when: ‘server’ not in group_names
  • template: …

The “group_names” variable is a special variable that contains a list of the groups the current host is in.

3

Thanks James,

That’s nice. One thing I’m not sure about is the ‘server_address_here’ which you wrote. Ideally, what I need there is the name/address of the first (and the only) host in the inventory group ‘server’.
Is there a way to do this?

Cheers,
Jacek

W dniu czwartek, 18 września 2014 01:41:55 UTC+1 użytkownik James Cammarata napisał:

4

Ok, after a little search I’ve got it; for anyone interested:

  • set_fact: address_variable={{ item }}
    with_items: groups.server
    when: “‘server’ not in group_names”

Cheers,
Jacek

W dniu piątek, 19 września 2014 14:06:25 UTC+1 użytkownik Jacek napisał:

5

I think this would be even better:

  • set_fact: address_variable={{ groups.server[0] }}
    when: “‘server’ not in group_names”

Looks nicer both in code and in output :wink:

Jacek jacek.cala@gmail.com napisał: