Run an Ansible task only when the variable contains a specific string

Question

I have multiple tasks depend from the value of variable1. I want to check if the value is in {{ variable1 }} but I get an error:

- name: do something when the value in variable1
  command: <command>
  when: "'value' in {{ variable1 }}"

I'm using ansible 2.0.2

Answer below works for me (well, I use it in `assert: ... that: ...`. What error do you see? — jhutar, Oct 01 '16 at 20:07

score 111 · Answer 1 · answered Apr 08 '16 at 10:35

111

If variable1 is a string, and you are searching for a substring in it, this should work:

when: '"value" in variable1'

if variable1 is an array or dict instead, in will search for the exact string as one of its items.

answered Apr 08 '16 at 10:35

guido

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this method works better, won't trigger warning as in `result|search` – Howard Lee Oct 17 '18 at 17:47
This only works in later versions of Ansible, for alternatives for earlier versions see other answers. – DustWolf Aug 12 '20 at 08:28
I was using that with ansible 1.9, if iI remember correctly; if I had to write it today I wouldn't use that. – guido Aug 12 '20 at 09:19

Denise Mauldin · Answer 2 · 2019-12-04T19:21:59.950

52

None of the above answers worked for me in ansible 2.3.0.0, but the following does:

when: variable1 | search("value")

In ansible 2.9 this is deprecated in favor of using ~ concatenation for variable replacement:

when: "variable1.find('v=' ~ value) == -1"

http://jinja.pocoo.org/docs/dev/templates/#other-operators

Other options:

when: "inventory_hostname in groups[sync_source]"

edited Dec 04 '19 at 19:21

answered May 25 '17 at 17:55

Denise Mauldin

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+1 I prefer this answer. You can also add 'not' before 'variable1' if you want to check that variable1 does not contain 'value'. when: not variable1 | search("value") – Montgomery 'monty' Jones Jun 22 '17 at 13:34
What if you want to negate / not this? Like if "value" is not in `variable1`? – Simon Woodside Mar 18 '18 at 04:43
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@SimonWoodside https://stackoverflow.com/questions/32786122/ansible-condition-when-string-not-matching – Denise Mauldin Mar 19 '18 at 16:39
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says this method to be deprecated in 2.9. Instead of using `result|search` use `result is search` – Howard Lee Oct 17 '18 at 17:29
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But the fact is I find `result|search` works better even with warning. Lot of discussion on this: https://github.com/ansible/ansible/issues/22397 – Howard Lee Oct 17 '18 at 17:42
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Use `'"value" in variable1'` as suggested in another solution, won't trigger warning. – Howard Lee Oct 17 '18 at 17:47
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using variable1.find is atrocious and unreadable compared to variable1 | search("") – Michael Noe Dec 04 '19 at 18:54

imjoseangel · Answer 3 · 2022-08-19T15:57:33.320

38

From Ansible 2.5

when: variable1 is search("value")

For negative scenarios

when: not variable1 is search("value")

edited Aug 19 '22 at 15:57

answered Aug 31 '18 at 09:31

imjoseangel

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Great it works in ansible 2.9! If I need a condition that works only when the variable does not contain a specific string, what is the correct syntax? I was thinking to something like this: `when: variable1 is not search("value")` but is not working... – gaetano Mar 19 '20 at 14:43
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Hi, it is `when: not variable1 is search("value")` – imjoseangel Mar 19 '20 at 14:52
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@imjoseangel, Please add "not" case to the answer too... – Sriman Aug 18 '22 at 12:00

score 18 · Answer 4 · edited Feb 11 '19 at 20:34

18

Some of the answers no longer work as explained.

Currently here is something that works for me in ansible 2.6.x

 when: register_var.stdout is search('some_string')

edited Feb 11 '19 at 20:34

Eric Aya

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answered Feb 11 '19 at 19:10

Drew

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score 9 · Answer 5 · edited May 13 '20 at 00:06

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This works for me in Ansible 2.9:

variable1 = www.example.com. 
variable2 = www.example.org. 

when: ".com" in variable1

and for not:

when: not ".com" in variable2

edited May 13 '20 at 00:06

Peyman Mohamadpour

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answered May 12 '20 at 17:32

Chirag Vyas

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object · Answer 6 · 2018-04-30T14:24:35.390

8

This example uses regex_search to perform a substring search.

- name: make conditional variable
  command: "file -s /dev/xvdf"
  register: fsm_out

- name: makefs
  command: touch "/tmp/condition_satisfied"
  when: fsm_out.stdout | regex_search(' data')

ansible version: 2.4.3.0

edited Apr 30 '18 at 14:24

answered Apr 30 '18 at 13:28

object

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score 8 · Answer 7 · answered Mar 04 '20 at 01:04

8

In Ansible version 2.9.2:

If your variable variable1 is declared:

when: "'value' in variable1"

If you registered variable1 then:

when: "'value' in variable1.stdout"

answered Mar 04 '20 at 01:04

mudricd

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score 6 · Answer 8 · answered Sep 13 '18 at 17:50

6

use this

when: "{{ 'value' in variable1}}"

instead of

when: "'value' in {{variable1}}"

Also for string comparison you can use

when: "{{ variable1 == 'value' }}"

answered Sep 13 '18 at 17:50

sdin

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when does not need curly braces: https://docs.ansible.com/ansible/latest/user_guide/playbooks_conditionals.html#id2 (today, no idea about 2013) – simohe Dec 01 '20 at 20:04

score -2 · Answer 9 · answered Mar 30 '17 at 13:10

-2

I used

failed_when: not(promtool_version.stdout.find('1.5.2') != -1)

means - failed only when the previously registered variable "promtool_version" doesn't contains string '1.5.2'.

answered Mar 30 '17 at 13:10

Wojciech Sciesinski

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Run an Ansible task only when the variable contains a specific string

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