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Release 2.2.0 of Virt-Lightning, a lightweight CLI for libvirt which can serve as an alternative to Vagrant. It’s also a stable API that you can use in Python to quickly spawn new VM, like you would do with a Cloud provider.

Most of the new features come from contributors and I’m pretty happy with this.

Changelog

• Cosmetic documentation changes
• Don’t try to fetch an image that already exists
• Add ability to boot old system with no virtio support
• Use Libvirt default settings when possible
• Use the VNC display by default
• Add support for OpenVSwitch (a.k.a OVS )bridge
• vl stop: avoid a Python backtrace if the VM doesn’t exist

Ansible-Navigator is a new terminal base UI for Ansible. It aims to provide an alternative to the different ansible commands that you probably already familiar with. To learn more about Ansible-Navigator, a couple of recent blog posts on Ansible Blog cover this new tool. The Execution Environment, or just EE, is also a rather recent concept. With a EE Ansible and all its dependencies are shipped as a single container. You don’t need anymore to care about the Python version, the virtualenv, the collections and Python dependency.

Ansible-Navigator provides an interface that is inspired by ansible-playbook. In this example we will see how we can use the CLI to run a playbook. My pass some credentials through environment variables, we will also see how to expose them properly.

The first thing is to prepare a ansible-navigator.yml file in your project directory.

---
ansible-navigator:
   execution-environment:
     container-engine: podman
     enabled: True
     image: myregister/ansible-automation-platform-21-ee-supported-rhel8:2.1.0
     pull-policy: never
     environment-variables:
        pass:
          - VMWARE_VALIDATE_CERTS
          - VMWARE_HOST
          - VMWARE_PASSWORD
          - VMWARE_USER
          - ESXI1_PASSWORD
          - ESXI1_HOSTNAME
          - ESXI1_USERNAME

The image key point on the container, I use a Fedora and Podman is the default for container. I ensure Navigator use the right engine with the container-engine: podman configuration. I use the environment-variables section to list all the variables that I want to expose in my container. If you want to read about all the other configuration options, just read the documentation at https://ansible-navigator.readthedocs.io/en/latest/.

If your playbook depends on some roles, for instance within a roles directory, it’s important to call ansible-navigator from the root directory of your project. Otherwise, the roles won’t be reachable from within the container. If your roles are maintained at a different location, you can still expose their directories with the volume-mounts option. This is in my opinion slightly less elegant.

[goneri@t580 targets]$ ls -lh
total 416K
-rw-r--r--. 1 goneri goneri  469 Oct 19 15:09 ansible-navigator.yml
drwxrwxr-x. 2 goneri goneri    6 Oct 19 15:39 playbooks
drwxrwxr-x. 2 goneri goneri    6 Oct 19 15:39 roles

Now, I can just run my playbook with: ansible-navigator run --mode stdout playbooks/vcenter_vm_scenario1

So, I’ve got an old phone with 35GB of picture that I want to save. So far, I tried NextCloud sync, scp copy, GIO/NTP file. For all of those, it’s a 12h+ operation. And the real solution is to enable the developer mode on the phone and go straight to adb:

$ adb pull /sdcard/DCIM
/sdcard/DCIM/: 5825 files pulled. 31.9 MB/s (37517869453 bytes in 1122.166s)

Python3 provides a new fancy library to manage pretty much all the Path related operations This is a really welcome improvement since the before that we had to use a long list of unrelated modules.

I recently had to chose between Pathlib and os.path to expand a string in the ~/path format to the absolute path. Since the performance was important I took the time to benchmark the two options:

#!/usr/bin/env python3

import timeit

setup = '''
from pathlib import PosixPath
'''
with_pathlib = timeit.timeit("abs_remote_tmp = str(PosixPath('~/.ansible/tmp').expanduser())", setup=setup)

setup = '''
from os.path import expanduser
'''

with_os_path = timeit.timeit("abs_remote_tmp = expanduser('~/.ansible/tmp')", setup=setup)

print(f"with pathlib: {with_pathlib}\nwith os.path: {with_os_path}")

os.path is just about 4 times faster (x1000000) for this very specific case. The fact we need to instantiate a PosixPath object has an impact. Also, once again we observe a nice performance boost with Python 3.8 onwards.