DNS Resolver on Server

DNS Resolver on Server
DNS - Domain Name System
Resolver Service can translate domain names to IP address. Usually ISP (Internet Service Provider) provides these settings automatically.
Famous public DNS
CloudFlare 1.1.1.1
Google. 8.8.8.8
Cisco.  208.67.222.222
Check my configuration file on MAC
> cat /etc/resolv.conf
#
# macOS Notice
#
# This file is not consulted for DNS hostname resolution, address
# resolution, or the DNS query routing mechanism used by most
# processes on this system.
#
# To view the DNS configuration used by this system, use:
#   scutil --dns
#
# SEE ALSO
#   dns-sd(1), scutil(8)
#
# This file is automatically generated.
#
domain wks.lsvid.com
nameserver 10.10.100.35
nameserver 10.10.100.45
nameserver 10.10.100.25
We can check that from Command Line as well
> scutil --dns | grep 'nameserver\[[0-9]*\]'
Get the DNS from Python
cat resolvconfReader.py
#!/usr/bin/env python
def get_resolvers():
resolvers = []
try:
with open( '/etc/resolv.conf', 'r' ) as resolvconf:
for line in resolvconf.readlines():
line = line.split( '#', 1 )[ 0 ];
line = line.rstrip();
if 'nameserver' in line:
resolvers.append( line.split()[ 1 ] )
return resolvers
except IOError as error:
return error.strerror
print( get_resolvers())
Easy python script to find that out
> python resolvconfReader.py
['10.10.100.35', '10.10.100.45', '10.10.100.25']

References:
https://superuser.com/questions/258151/how-do-i-check-what-dns-server-im-using-on-mac-os-x
https://github.com/donjajo/py-world/blob/master/resolvconfReader.py