QA Failure for vmimage extractor (vmimage.py): libguestfs configuration on Ubuntu

[ArkaprabhaChakraborty]

CI job for any builds on Ubuntu 22 fails due to:

extractcode.ExtractErrorFailedToExtract: Unable to read kernel at: /boot/vmlinuz-6.5.0-1025-azure.
libguestfs requires the kernel executable to be readable.
This is the case by default on most Linux distributions except on Ubuntu.

This exception is raised at:

2025-01-25T13:22:44.5081493Z            for kern in kernels:
2025-01-25T13:22:44.5081633Z                 if not os.access(kern, os.R_OK):
2025-01-25T13:22:44.5081786Z >                   raise ExtractErrorFailedToExtract(
2025-01-25T13:22:44.5081938Z                         f'Unable to read kernel at: {kern}.\n'
2025-01-25T13:22:44.5082088Z                         f'{GUESTFISH_KERNEL_NOT_READABLE}'
2025-01-25T13:22:44.5082214Z                     )

This could be handled using mocking for testing scenarios. However, more research is required on how such mocking can be implemented.

[ArkaprabhaChakraborty]

I'll try to make a pull request for this.

[ArkaprabhaChakraborty]

def is_kernel_readable():
    """
    Check if the kernel is readable by testing access to /boot/vmlinuz-*.
    Return True if readable, False otherwise.
    """
    if not os.name == "posix":
        return False  # Skip on non-Linux systems

    try:
        kernels = list(Path("/boot").glob("vmlinuz-*"))
        if not kernels:
            return False  # No kernel found
        return all(os.access(kern, os.R_OK) for kern in kernels)
    except Exception:
        return False  # Kernel check failed

@pytest.mark.skipif(not on_linux, reason='Only linux supports image extraction')

can fix the kernel not readable CI bug for now.