func VMTapPair()

in cni/internal/cniutil.go [71:107]

• 29 lines of code
• 5 McCabe index (conditional complexity)

func VMTapPair(
	result *current.Result,
	vmID string,
) (
	vmIface *current.Interface,
	tapIface *current.Interface,
	err error,
) {
	vmIfaces, otherIfaces := FilterBySandbox(vmID, result.Interfaces...)
	if len(vmIfaces) > 1 {
		return nil, nil, errors.Errorf(
			"expected to find at most 1 interface in sandbox %q, but instead found %d",
			vmID, len(vmIfaces))
	} else if len(vmIfaces) == 0 {
		return nil, nil, LinkNotFoundError{device: fmt.Sprintf("pseudo-device for %s", vmID)}
	}

	vmIface = vmIfaces[0]

	// As specified in the package docstring, the vm interface is given the same name as the
	// corresponding tap device outside the VM. The tap device, however, will be in a sandbox
	// corresponding to a network namespace path.
	tapName := vmIface.Name

	tapIfaces := IfacesWithName(tapName, otherIfaces...)
	if len(tapIfaces) > 1 {
		return nil, nil, errors.Errorf(
			"expected to find at most 1 interface with name %q, but instead found %d",
			tapName, len(tapIfaces))
	} else if len(tapIfaces) == 0 {
		return nil, nil, LinkNotFoundError{device: tapName}
	}

	tapIface = tapIfaces[0]

	return vmIface, tapIface, nil
}