Function flush_dns_cache

updateHostsFile.py:1468–1556

Flush the DNS cache.

()

def flush_dns_cache():
    """
    Flush the DNS cache.
    """

    print("Flushing the DNS cache to utilize new hosts file...")
    print(
        "Flushing the DNS cache requires administrative privileges. You might need to enter your password."
    )

    dns_cache_found = False

    if platform.system() == "Darwin":
        if subprocess.call(SUDO + ["killall", "-HUP", "mDNSResponder"]):
            print_failure("Flushing the DNS cache failed.")
    elif os.name == "nt":
        print("Automatically flushing the DNS cache is not yet supported.")
        print(
            "Please copy and paste the command 'ipconfig /flushdns' in "
            "administrator command prompt after running this script."
        )
    else:
        nscd_prefixes = ["/etc", "/etc/rc.d"]
        nscd_msg = "Flushing the DNS cache by restarting nscd {result}"

        for nscd_prefix in nscd_prefixes:
            nscd_cache = nscd_prefix + "/init.d/nscd"

            if os.path.isfile(nscd_cache):
                dns_cache_found = True

                if subprocess.call(SUDO + [nscd_cache, "restart"]):
                    print_failure(nscd_msg.format(result="failed"))
                else:
                    print_success(nscd_msg.format(result="succeeded"))

        centos_file = "/etc/init.d/network"
        centos_msg = "Flushing the DNS cache by restarting network {result}"

        if os.path.isfile(centos_file):
            if subprocess.call(SUDO + [centos_file, "restart"]):
                print_failure(centos_msg.format(result="failed"))
            else:
                print_success(centos_msg.format(result="succeeded"))

        system_prefixes = ["/usr", ""]
        service_types = ["NetworkManager", "wicd", "dnsmasq", "networking"]
        restarted_services = []

        for system_prefix in system_prefixes:
            systemctl = system_prefix + "/bin/systemctl"
            system_dir = system_prefix + "/lib/systemd/system"

            for service_type in service_types:
                service = service_type + ".service"
                if service in restarted_services:
                    continue