role parameters in Ansible

Shock! There is a way to beat register/set_fact!

Today I have a fierce discussion about Ansible imperfections. My argument was that Ansible totally lack isolation of variables (there is no ‘private’ variables with default…

Systemd nuances with .target/.service dependencies.

Today I gave no rants. Systemd is doing a great job to think about all nuances of a service start. When an administrator uses it, and all units are written properly, it’s a bliss to use.

How to remove a pool in Ceph without restarting mons

Every new version of Ceph is making harder and harder to shoot oneself in the leg. If you want to delete a pool, older versions just ask you name of the pool twice and the option --yes-i-really-really-mean-it. Newer versions are not so…

Packaging a single module in Python

Are you tired of endless __init__.py in your code?

At recent code review my colleague pointed out to a lot of code inside __init__.py. I looked at those things with fresh eye and found, that many things I…

Using default value if string is empty

This little python trick works great in Ansible.

Let’s say you want to set foo to value of the bar, but only if bar is not empty. If bar is empty, you want to use other value (f.e. string “nothing”).

Converting feature flags into groups in Ansible

There is a specific case when you want to execute a play for hosts with a specific attribute. For sake of illustration I’ll use hardware_raid: true in all examples, but it should be equally useful for all other cases.

The way to handle CI-owned ssh keys in Gitlab

I’d like to present the alternative approach to solving endless struggle with ‘deliver CI credentials in a safe and ergonomic way’.

The problem

Custom chains in iptables with Ansible

I was really upset when I realized that an Ansible iptables module does not support creation of custom chains. Initially I’ve assumed they’re going to be creates automatically, as soon as I added a single rule into a new chain. Nope.

Working with go-templates in Ansible

!unsafe

There was an endless pain on templatization of yaml files containing go-inspired string interpolation. The most known culprits are Prometheus and Kapacitor. The Prometheus is the most outstanding because it has yaml as format…

Ansible variables precedence

This topic I really don’t like. There are so many entities in priority list (places to put variables) that it’s impossible to remember. Moreover, it’s impossible to recognize.