# How to do math in Ansible? **URL:** \ **Category:** Ansible Project\ **Created:** [January 22, 2018, 5:18pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531 "2018-01-22T17:18:34Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![ZillaYT](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@ZillaYT](https://forum.ansible.com/u/ZillaYT)\ **Post date:** [January 22, 2018, 5:18pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/1 "2018-01-22T17:18:34Z")
I have an Ansible task that aims to upgrade our Gitlab application. I want the user to ONLY be able to upgrade 1 major release. For example, I want to enable a 8.x to 9.x upgrade, but not an 8.x to 10.x upgrade. I’m aware of the version\_compare module, which I use, but need more than what it does. I did write a filter that extracts the major, minor, patch versions of a Semver-format version so I can get the major part. But how do I then compare them to see if their difference is \> 1? I do… ` # NOTE: server\_major is a filter I wrote to extract the major version of an M.m.p Semver-format version. - name: Get major version of installed version set\_fact: M\_installed=installed\_version|sermver\_major - name: Get the major version of the desired upgrade version set\_fact: M\_upgrade=upgrade\_version|semver\_major - name: Ensure M\_upgrade - M\_installed = 1 “How do I do this?” ` Maybe there is a more straight-forward way to do this? ---
**Author:** ![sivel](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/sivel/32/1198_2.png) [@sivel](https://forum.ansible.com/u/sivel)\ **Post date:** [January 22, 2018, 5:30pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/2 "2018-01-22T17:30:08Z")
Probably something like: - name: Ensure M\_upgrade - M\_installed = 1 assert: that: - M\_upgrade|int - M\_installed|int == 1 ---
**Author:** ![Kai\_Stian\_Olstad](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@Kai\_Stian\_Olstad](https://forum.ansible.com/u/Kai_Stian_Olstad)\ **Post date:** [January 22, 2018, 5:32pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/3 "2018-01-22T17:32:47Z")
If you are using apt I would suggest another way of solving this and that is pinning in apt Just create a file /etc/apt/preferences.d/gitlab with the following content Package: gitlab-ce Pin: version /9.[0-9]+\.[0-9]+-/ Pin-Priority: 1000 You can read more about pinning here [https://wiki.debian.org/AptPreferences](https://wiki.debian.org/AptPreferences) ---
**Author:** ![ZillaYT](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@ZillaYT](https://forum.ansible.com/u/ZillaYT)\ **Post date:** [January 22, 2018, 6:23pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/4 "2018-01-22T18:23:29Z")
I’m using yum (RHEL). However with this approach, don’t you have to update the file when the major version changes? ---
**Author:** ![ZillaYT](https://avatars.discourse-cdn.com/v4/letter/z/4da419/32.png) [@ZillaYT](https://forum.ansible.com/u/ZillaYT)\ **Post date:** [January 22, 2018, 6:33pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/5 "2018-01-22T18:33:12Z")
Thanks, I’l try this ---
**Author:** ![Kai\_Stian\_Olstad](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@Kai\_Stian\_Olstad](https://forum.ansible.com/u/Kai_Stian_Olstad)\ **Post date:** [January 23, 2018, 2:54pm UTC](https://forum.ansible.com/t/how-to-do-math-in-ansible/26531/6 "2018-01-23T14:54:50Z")
With that regex yes, it's a nice way to control upgrade to major versions. And it also preventing upgrade of a package if someone should run apt dist-upgrade (equivalent to yum upgrade) My file for Gitlab looks like this $ more /etc/apt/preferences.d/gitlab Package: gitlab-ce Pin: version /[0-9]+\.[0-9]+\.([5-9]-|[0-9]{2,}-)/ Pin-Priority: 1000 It only upgrade if the package is x.y.5 or higher, the reason for this is Gitlab tends to be very buggy until around x.y.5 version is released.