Using dynamic groups in ansible

When we have a condition which need to be checked for many tasks, it may be advisable to just exclude hosts (based on this condition) from been run at all.

I played with idea of dynamic groups, and here are my observations.

Why smartctl could not be run without root

As you can guess, this title gives answer to the question: ‘How to run smartctl from a normal user?’. The answer is ‘no way. Root only’.

Here are detailed explanation.

when ‘when’ starts with a string

It’s a small post about trivial thing, but someone need to write it down.

Let’s say we have a playbook:

- foo: args=args
  when: 'foo' in bar

An unexpected trap with variable_start_string/variable_end_string

There are two features of Ansible:

1. Lazy evaluation of jinja2. If you set your variable foo to ‘{{some_var}}’, it’s not set to the value of some_var, instead it become a literal…