def lock_kernel_updates()

in linux/cuda_installer/os_installers/dnf_system.py [0:0]

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

    def lock_kernel_updates(self):
        """Make sure no kernel updates are installed."""
        logger.info("Attempting to update /etc/dnf/dnf.conf to block kernel updates.")

        conf_parser = configparser.ConfigParser()
        conf_parser.read("/etc/dnf/dnf.conf")
        if "exclude" in conf_parser["main"]:
            value = conf_parser["main"]["exclude"]
            if "kernel*" in value:
                logger.info("Kernel updates are already blocked in /etc/dnf/dnf.conf")
                return
            value = [s.strip() for s in value.split(",")]
            value.append("kernel*")
        else:
            value = ["kernel*"]
        conf_parser["main"]["exclude"] = ", ".join(value)

        shutil.copyfile("/etc/dnf/dnf.conf", "/etc/dnf/dnf.conf_backup")
        try:
            with open("/etc/dnf/dnf.conf", mode="w") as dnf_conf_file:
                conf_parser.write(dnf_conf_file)
        except Exception as e:
            logger.error(
                "Failed to update /etc/dnf/dnf.conf due to {}. Restoring config file from backup.".format(
                    e
                )
            )
            shutil.copyfile("/etc/dnf/dnf.conf_backup", "/etc/dnf/dnf.conf")
            raise e
        else:
            logger.info(
                "Kernel updates blocked by `exclude` entry in /etc/dnf/dnf.conf"
            )