Ansible 2.5 migration guide

Today the new version of Ansible 2.5 has appeared in the package manager repository. Generally speaking there are long migration documention documents releases if a new version of ansible is released.

At the moment I will not migrate to version 2.5 since I wait for the first bugs to be fixed. Also the syntax logic in the .yaml files has been changed from

when:
    - result | failed
    - not result | success

to this one:

when:
    - result is failed
    - results is not successful

Further notices regarding the migration can be found in the porting guide.