Feat/app

[yanksyoon]

Force pushing due to unsigned commits closed #2 and github currently cannot reopen closed PRs due to foce push, hence a new PR.

Applicable spec: N/A

Overview

Creates an installable python application that will be used by github-runner-image-builder-operator charm to manage building of images.
The application creates a chroot environment from Ubuntu cloud-images and pre-installs and pre-configures executables.
The uploading of images have been omitted deliberately due to the testing overhead that arises from including Openstack.

Rationale

To provide a workload for github-runner-image-builder-operator charm.

Module Changes

The modules are as follows:

• cli - provides entrypoint and parsing args
• bulider - handles the building of image within the chroot env
• chroot - provides a context-managed chroot environment
• config - configuration data types
• utils - utility functions, e.g. retry

TODO (in a follow up PR):

• reorder the functions to be in step down order to cater for recent changes in contributing guide.
• Missing repository configurations.

Checklist

• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

The following is the result of running the test on the ARM64 AWS instance. The error is due to unavailability of private-endpoint-arm runners and hence the failure to cleanup Openstack image resources.

The following is the result of testing on PS6 ARM64 runner instances.

[yanksyoon]

The test is failing due to: canonical/pylxd#580 should be fixed when it lands on pypi.

[yanksyoon]

0.1 -> 1.0.0 after stable