# Changes in Release 0.5

Major changes in Release 0.5:

* containerlab virtualization provider
* More flexible virtualization provider framework (see below)
* System topology defaults have been moved into the library subdirectory (to be read with *importlib.resources* functions)

Bug fixes:

* Set OSPF subnet mask on unnumbered interfaces on Arista EOS
* Replace underscores with dashes in Arista EOS hostnames

## Flexible virtualization providers framework

* Virtualization provider can be defined in a dynamically loaded Python module
* Device- and addressing defaults can be specified within provider defaults (example: use different username on containerized Arista EOS than on Vagrant box)
* Provider-specific node data is copied from provider default into node data structure
* Virtualization provider can specify hostname to be used in Ansible inventory (needed by containerlab)

## Internal changes

* Renamed library directories -- preparing to publish the solution as a Python package
* Reorganized unit tests into subdirectories