install_r45_on_ubuntu_1804lts_doc/configure_netplan.py

#!/usr/bin/python3
import sys
import os
import yaml
import subprocess
import ipaddress
import re
def main():
    args = sys.argv
    if len(args) < 2:
        print(f"Usage: {args[0]} /etc/netplan/00-installer-config.yaml")
        sys.exit()
    netplan_config_file = args[1]
    with open(netplan_config_file, 'r') as f:
        org_file_contents = f.read()
        netplan_config_yaml = yaml.safe_load(org_file_contents)
    if netplan_config_yaml == None:
        netplan_config_yaml = {}
    addresses = {}
    gateway4 = {}
    dhcp = {}
    network_block = netplan_config_yaml.get('network')
    no_network_block = False
    no_ethernets_block = False
    if network_block == None:
        no_network_block = True
        no_ethernets_block = True
    else:
        ethernets_block = network_block.get('ethernets')
        if ethernets_block == None:
            no_ethernets_block = True
        else:
            need_remove_interfaces = []
            for interface in ethernets_block:
                interface_block = ethernets_block[interface]
                interface_addresses = interface_block.get('addresses')
                if interface_addresses != None:
                    if len(interface_addresses) != 0:
                        addresses[interface] = interface_addresses
                elif interface == '':
                    need_remove_interfaces.append(interface)
            for interface in need_remove_interfaces:
                del netplan_config_yaml['network']['ethernets'][interface]
    if len(addresses) != 0:
        print("You alreay configure some addresses for interfaces!")
        for interface in addresses:
            interface_addresses = addresses[interface]
            for addr in interface_addresses:
                print(f"{interface}: {addr}")
        ans = input("Do you want to continue configure? (y/n)")
        if ans.lower() != "y":
            sys.exit()
    default_interfaces = list(set(subprocess.Popen("ip -o -4 route show to default | awk '{print $5}'", shell=True, stdout=subprocess.PIPE).stdout.read().decode().strip().split("\n")))
    if '' in default_interfaces:
        default_interfaces.remove('')
    if len(default_interfaces) == 0:
        default_interfaces.extend(subprocess.Popen("ls /sys/class/net/|xargs", shell=True, stdout=subprocess.PIPE).stdout.read().decode().strip().split(" "))
        if 'lo' in default_interfaces:
            default_interfaces.remove('lo')
    if len(default_interfaces) == 0:
        if len(args) > 2:
            default_interfaces = args[2]
        else:
            print("No network interface detected!")
            print(f"Usage: {args[0]} /etc/netplan/00-installer-config.yaml $interface_name")
            sys.exit()
    change_flag = False
    for interface in default_interfaces:
        old_address = addresses.get(interface)
        if old_address != None:
            for addr in old_address:
                print(f"Found {addr} for interface {interface}!")
            ans = input("Do you want to continue configure? (y/n)")
            if ans.lower() != "y":
                continue
        new_addr = ""
        dhcp4 = input(f"Do you want to use dynamic address(dhcp) for interface {interface}? (y/n)")
        if dhcp4.lower() != "y":
            dhcp4 = False
            while new_addr == "":
                new_addr = input(f"New address for interface {interface}: ")
                try:
                    ipaddress.IPv4Address(new_addr)
                except:
                    print("Invalid ipaddress!")
                    new_addr = ""
            addresses[interface] = [new_addr + '/24']
            new_gateway4 = input(f"New gateway4 for interface {interface}: (can leave blank by default 254)")
            gateway4[interface] = re.sub('[\\d]+$', '254', new_addr)
            if new_gateway4 != "":
                try:
                    ipaddress.IPv4Address(new_gateway4)
                    gateway4[interface] = new_gateway4
                except:
                    print("Invalid gateway4 ipaddress!")
                    print(f"Change to default: {gateway4[interface]}")
            change_flag = True
        else:
            change_flag = True
            dhcp4 = True
            if old_address != None:
                del addresses[interface]
        dhcp[interface] = dhcp4
    if no_network_block:
        netplan_config_yaml['network'] = {}
        change_flag = True
    if no_ethernets_block:
        change_flag = True
        netplan_config_yaml['network']['ethernets'] = {}
        if netplan_config_yaml['network'].get('version') == None:
            netplan_config_yaml['network']['version'] = 2
    if change_flag:
        for interface in default_interfaces:
            interface_content = netplan_config_yaml['network']['ethernets'].get(interface)
            if interface_content == None:
                interface_content = {}
                netplan_config_yaml['network']['ethernets'][interface] = interface_content
            new_addr = addresses.get(interface)
            if new_addr != None:
                if type(new_addr) != list:
                    new_addr = [new_addr]
                netplan_config_yaml['network']['ethernets'][interface]['addresses'] = new_addr
            else:
                tmp = netplan_config_yaml['network']['ethernets'][interface]
                if tmp.get('addresses') != None:
                    del netplan_config_yaml['network']['ethernets'][interface]['addresses']
                if tmp.get('nameservers') != None:
                    del netplan_config_yaml['network']['ethernets'][interface]['nameservers']
                if tmp.get('gateway4') != None:
                    del netplan_config_yaml['network']['ethernets'][interface]['gateway4']
            new_gateway4 = gateway4.get(interface)
            if new_gateway4 != None:
                netplan_config_yaml['network']['ethernets'][interface]['gateway4'] = new_gateway4
            dhcp4 = dhcp.get(interface)
            if dhcp4 != None:
                netplan_config_yaml['network']['ethernets'][interface]['dhcp4'] = dhcp4
            nameservers = interface_content.get('nameservers')
            if nameservers == None and dhcp4 == False:
                nameservers = {'addresses': []}
            if nameservers != None:
                nameservers_addresses = nameservers.get('addresses')
                if nameservers_addresses != None:
                    default_nameservers = ['8.8.8.8', '8.8.4.4']
                    for nameserver in default_nameservers:
                        if nameserver not in nameservers_addresses:
                            nameservers_addresses.append(nameserver)
                    nameservers['addresses'] = nameservers_addresses
                    netplan_config_yaml['network']['ethernets'][interface]['nameservers'] = nameservers
        with open(netplan_config_file, 'w+') as f:
            yaml.dump(netplan_config_yaml, f)
            netplan_get_status = os.system('sudo netplan get')
            if netplan_get_status == 0:
                if os.system('sudo netplan try --timeout 10') == 0:
                    print("Finish configuring netplan!")
                    sys.exit(0)
            else:
                print("Something went wrong!")
                f.write(org_file_contents)
                print("Recover changed!")
                sys.exit(1)
        with open(netplan_config_file, 'w+') as f:
            print(org_file_contents)
            f.write(org_file_contents)
            print("Recover changed!")
if __name__ == '__main__':
    main()