DynamicHosts/dns-manage at master · greypanda/DynamicHosts · GitHub

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#! /usr/bin/python3

"""
     Manage host dns by creating/deleting symbolic links from
     /etc/dnsmasq.d/hosts.enabled to /etc/dnsmasq.d/hosts.available.

    There should be no need to restart dnsmasq, but adding symbolic links doesn't
    seem to trigger a reload of the config..


    The program is invoked by using symbolic links. The links are named:

        dns-enable -- enable a host
        dns-disable -- disable a host
        dns-list -- list all hosts

"""
DNSMASQ_ETC = '/etc/dnsmasq.d'
DNSMASQ_AVAILABLE = DNSMASQ_ETC + '/hosts.available'
DNSMASQ_ENABLED = DNSMASQ_ETC +   '/hosts.enabled'
DNSMASQ_CFG_SUFFIX = ".dns"

import argparse
import sys
import os
from os.path import isfile,join
import subprocess

def find(name,path):
	for root,dirs,files in os.walk(path):
		if name + DNSMASQ_CFG_SUFFIX in files:
			return os.path.join(root,name + DNSMASQ_CFG_SUFFIX)
		else:
			return None

def restart():
	"""
		restart naemon
	"""
	subprocess.run(['/bin/systemctl','restart', 'naemon'])

def enhost(host):
    """
	First, search the available hosts directory for the
	desired host. If it doesn't exist, exit...

	Next, search the enabled hosts directory for the
	desired host. If it exists, exit...

	Create a symbolic link in the enabled directory.


    """
    available = find(host,DNSMASQ_AVAILABLE)
    if not available:
        print("%s not found in available directory -- " % host + DNSMASQ_AVAILABLE)
        return

    enabled = find(host,DNSMASQ_ENABLED)
    if enabled:
        print("%s is already enabled" % host)
        return
    src = available
    dest = DNSMASQ_ENABLED + '/' + host + DNSMASQ_CFG_SUFFIX
    print("Linking %s to %s" % (src,dest))
    os.symlink(src,dest)
    restart()
    listhosts()

def dishost(host):
    available = find(host,DNSMASQ_AVAILABLE)
    if not available:
        print("%s not found in available directory -- " % host + DNSMASQ_AVAILABLE)

    enabled = find(host,DNSMASQ_ENABLED)
    if not enabled:
        print("%s is not enabled" % host)
        return
    print("Removing %s" % enabled)
    os.remove(enabled)
    restart()
    listhosts()

def listhosts():
	print("Available:")
	files = [f for f in os.listdir(DNSMASQ_AVAILABLE) if isfile(join(DNSMASQ_AVAILABLE,f))]
	for file in files:
		print("\t" + file)


	print("Enabled:")
	files = [f for f in os.listdir(DNSMASQ_ENABLED) if isfile(join(DNSMASQ_ENABLED,f))]
	for file in files:
		print("\t" + file)


if __name__ == "__main__":
    command = os.path.basename(sys.argv[0])
    if command == 'dns-enable':
        enhost(sys.argv[1])
    elif command == 'dns-disable':
        dishost(sys.argv[1])
    elif command == 'dns-list':
        listhosts()
    else:
        print("Use dns-enable, dns-disable, dns-list instead")
    sys.exit()