Ansible - How to do integer comparison in a conditional?

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.

• Wiktor Stribiżew: Note the dot must be escaped, '[0-9]+\\.[0-9]+'
• Viscosity: Understood, and fixed that, but no change with the underlying problem.
• Vladimir Botka: Do not register w. Put the declaration into the vars. See below. Then, the condition should work as expected.

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 }}"

• Viscosity: Vladimir, I tried to implement this, but I got an error right during my debug print of the variable: fatal: [server1]: FAILED! => {"msg": "template error while templating string: no filter named 'split'. String: {{ sqlversion|split(',')|first|split()|last }}"} Not sure if it matters, but I also am forced on this series of machines to use ansible 2.9. I know split must exist as a filter because I used it in my own example, so not sure why it's complaining.
• 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
• Viscosity: You are a scholar and a gentleman sir, when using the code from the line because the split filter is not available, it now gives me the results and comparisons that I expected. This is the answer for people forced into older Ansible version usage.

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.

• Viscosity: Thanks for the information, I will definitely keep it in mind.