71 lines
2.7 KiB
Python
Executable File
71 lines
2.7 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
|
|
import argparse
|
|
import sys
|
|
import time
|
|
import dns.query
|
|
import dns.message
|
|
import socket
|
|
|
|
def resolve_dns_server_ip(server):
|
|
try:
|
|
ip_address = socket.getaddrinfo(server, None, family=socket.AF_INET)[0][4][0]
|
|
except socket.gaierror:
|
|
raise ValueError("Failed to resolve DNS server domain")
|
|
return ip_address
|
|
|
|
def main():
|
|
parser = argparse.ArgumentParser(description='Check DNS-over-TLS connectivity and response time')
|
|
parser.add_argument('-c', '--critical', type=float, default=500, help='Critical threshold for response time in milliseconds (default: 500)')
|
|
parser.add_argument('-w', '--warning', type=float, default=300, help='Warning threshold for response time in milliseconds (default: 300)')
|
|
parser.add_argument('-d', '--domain', type=str, default='google.com', help='Domain to resolve (default: google.com)')
|
|
parser.add_argument('-s', '--server', type=str, required=True, help='DNS server address')
|
|
parser.add_argument('-p', '--port', type=int, default=853, help='Port to use for DNS-over-TLS (default: 853)')
|
|
args = parser.parse_args()
|
|
|
|
try:
|
|
server_ip = resolve_dns_server_ip(args.server)
|
|
except ValueError as e:
|
|
print(f'CRITICAL - {str(e)}')
|
|
sys.exit(2)
|
|
|
|
error_message = None
|
|
query = dns.message.make_query(args.domain, dns.rdatatype.A)
|
|
start_time = time.time()
|
|
try:
|
|
response = dns.query.tls(query, server_ip, port=args.port, timeout=args.critical)
|
|
except dns.exception.SyntaxError:
|
|
error_message = "invalid IP address or domain name"
|
|
except dns.exception.Timeout:
|
|
error_message = "the DNS operation timed out"
|
|
except Exception as e:
|
|
error_message = e
|
|
|
|
if error_message:
|
|
print(f'CRITICAL - DNS-over-TLS query failed: {error_message}')
|
|
sys.exit(2)
|
|
|
|
|
|
response_time = time.time() - start_time
|
|
response_time_ms = int(response_time * 1000)
|
|
|
|
if response.rcode() != dns.rcode.NOERROR:
|
|
print(f'CRITICAL - DNS query returned error: {dns.rcode.to_text(response.rcode())}')
|
|
sys.exit(2)
|
|
|
|
resolved_ips = [str(rr.address) for rr in response.answer[0] if rr.rdtype == dns.rdatatype.A]
|
|
perfdata = f'Resolved IPs: {", ".join(resolved_ips)} | response_time={response_time_ms}ms;{args.warning};{args.critical};0;'
|
|
|
|
if response_time_ms >= args.critical:
|
|
print(f'CRITICAL - DNS-over-TLS response time: {response_time:.2f} sec.')
|
|
sys.exit(2)
|
|
elif response_time_ms >= args.warning:
|
|
print(f'WARNING - DNS-over-TLS response time: {response_time:.2f} sec.')
|
|
sys.exit(1)
|
|
else:
|
|
print(f'OK - DNS-over-TLS response time: {response_time:.2f} sec. {perfdata}')
|
|
sys.exit(0)
|
|
|
|
if __name__ == '__main__':
|
|
main()
|