Ansible - How to do integer comparison in a conditional? - regex

Question

I am trying to do a simple integer comparison in a conditional but something is up, and it is not evaluating properly.
Code within playbook:
- name: Check the version of the current sql database on both dispatchers and save that value.
command: /usr/bin/mysql -V
changed_when: false
register: sqlversion
- name: Print to the screen the current sql database version.
debug:
var: "{{ sqlversion.stdout.split()[4] | regex_search('[0-9]+\\.[0-9]+') | replace(\".\",'') }}"
register: w
- name: Show the value of the variable.
debug:
var: w
- name: Test result
command: w
when: ( w | int < 55 )
The output of the command module (ultimately to get the 5.5 part of the 5.5.43 number:
mysql Ver 14.14 Distrib 5.5.43, for Linux (x86_64) using readline 5.2
My actual run in which the Test result task "fails" as in it runs when it should not, because of the evaluation problem:
TASK [Check the version of the current sql database on both dispatchers and save that value.] ***********
ok: [server2]
ok: [server1]
TASK [Print to the screen the current sql database version.] ********************************************
ok: [server1] => {
"55": "55"
}
ok: [server2] => {
"55": "55"
}
TASK [Show the value of the variable.] ******************************************************************
ok: [server1] => {
"w": {
"55": "55",
"changed": false,
"failed": false
}
}
ok: [server2] => {
"w": {
"55": "55",
"changed": false,
"failed": false
}
}
TASK [Test result] **************************************************************************************
changed: [server1]
changed: [server2]
This is not right or expected, clearly the last task shows "changed" in that it ran, and evaluated the condition as true when it shouldn't be. Instead with how I coded the conditional, it should be skipped instead! Additionally, if I take away the " | int" then it always skips no matter what the number(s) are.
What's the issue here? There's got to be a way to make this work.

Answer 1

Simplify the parsing
w: "{{ sqlversion.stdout|split(',')|first|split()|last }}"
gives
w: 5.5.43
Use the test version. See Comparing versions. For example,
- debug:
msg: Version is lower than 5.6
when: w is version('5.6', '<')
Example of a complete playbook for testing
- hosts: localhost
vars:
sqlversion:
stdout: "mysql Ver 14.14 Distrib 5.5.43, for Linux (x86_64) using readline 5.2"
w: "{{ sqlversion.stdout|split(',')|first|split()|last }}"
tasks:
- debug:
var: w
- debug:
msg: Version is lower than 5.6
when: w is version('5.6', '<')
If the filter split is not available use the method twice
w: "{{ (sqlversion.stdout.split(',')|first).split()|last }}"

Answer 2

... but I also am forced on this series of machines to use Ansible 2.9 ...
As mentioned by Vladimir Botka
If the filter split is not available use the method twice. I added an example. The filter split is available since 2.11
the split filter for manipulation strings is available as of Ansible v2.11 but you can just use the Python method .split().
As a workround in Ansible v2.9 or 2.10 one could also implement a Custom Filter Plugin and so a simple Ansible Jinja2 filter to split a string into a list. By doing this a filter like | split() can made be available in older versions.