Simple Math with String to Int

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1

Hi All,

Im having trouble with setting a fact, doing some math, and having the result be an INT

To start, i set the base Var

set_fact: SOMENUMBER = 8

Ansible stores this value as a String

Later, i need to divide that number by 2 and get the result as an INT

set_fact: myvar = “{{ SOMENUMBER / 2) }}”

Even then though, Ansible stores it as a string.

If I do this, i get an INT, but its a FLOAT 4.0 instead of 4

set_fact: myvar = “{{ ((SOMENUMBER|int) / 2) }}”

I am having to resort to doing the following to get my answer of 4

set_fact: myvar = “{{ ((SOMENUMBER|int) / 2)|replace(‘.0’,‘’) }}”

Is there a better way to take a single integer stored as a string, and perform math and output an INT more simply?

TIA!

2

I'm afraid there isn't any. Jinja is a template engine, hence the default
output is a string. This was the intention of the developers, I think.
Otherwise one would have to explicitly convert the output of mathematics
expressions to strings.

Some notes to the examples:

* The output of the example isn't INT. It's a string. The consequent task
  confirms this

    - debug:
        msg: Variable myvar is a string
      when: myvar is string

* Also the following task will fail

    - debug:
        msg: "{{ myvar + 4 }}"

  with error message:

    "Unexpected templating type error occurred on ({{ myvar + 4 }}):
     coercing to Unicode: need string or buffer, int found"

* Instead the conversion to integer works as expected

    - debug:
        msg: "{{ myvar|int + 4 }}"

  gives:

    "msg": "8"

HTH
    -vlado

3

Jinja2 native types introduced in Ansible 2.7 should be what you want:
https://docs.ansible.com/ansible/latest/reference_appendices/config.html#default-jinja2-native

Martin

4

Thank You

I will check that out

Much appreciated