Very simple unit test for DNS

dns_test.py

import unittest
import yaml
import dns.resolver

# Load the YAML file
with open('dns_tests.yaml', 'r') as file:
    test_cases = yaml.safe_load(file)

class TestDNSLookup(unittest.TestCase):
    def dns_lookup(self, host, record_type):
        try:
            answers = dns.resolver.resolve(host, record_type)
            return [str(rdata) for rdata in answers]
        except Exception as e:
            return str(e)

    def test_dns_lookups(self):
        domain = test_cases['test']['domain']
        for test in test_cases['test']['records']:
            with self.subTest(test=test):
                host = f"{test['host']}.{domain}"
                record_type = test['type']
                expected_value = test['value']
                result = self.dns_lookup(host, record_type)
                if isinstance(result, list):
                    contains_expected = any(expected_value in r for r in result)
                    print(f"Hostname: {host}, Type: {record_type}, Expected: {expected_value}, Result: {result}")
                    self.assertTrue(contains_expected, f"Failed lookup for {host} {record_type}")
                else:
                    print(f"Hostname: {host}, Type: {record_type}, Expected: {expected_value}, Result: {result}")
                    self.fail(f"DNS lookup failed for {host} {record_type} with error: {result}")

if __name__ == '__main__':
    unittest.main()

dns_tests.yaml

---
test:
  domain: domain.com
  records:
    - host: go
      type: CNAME
      value: sites.domain.cloud
    - host: k1._domainkey.e
      type: TXT
      value: k=rsa; p=xxxxxxxxxxxxxxxxxxxxx
    - host: e
      type: TXT
      value: v=spf1 include:mailgun.org ~all
    - host: email.e
      type: CNAME
      value: mailgun.org
    - host: e
      type: MX
      value: mxa.mailgun.org
    - host: e
      type: MX
      value: mxb.mailgun.org

output.txt

❯ python dns_test.py
Hostname: go.domain.com, Type: CNAME, Expected: sites.domain.cloud, Result: ['sites.domain.cloud.']
Hostname: k1._domainkey.e.domain.com, Type: TXT, Expected: k=rsa; p=xxxxxxxxxxxxxxxxxxxxx"']
Hostname: e.domain.com, Type: TXT, Expected: v=spf1 include:mailgun.org ~all, Result: ['"v=spf1 include:mailgun.org ~all"']
Hostname: email.e.domain.com, Type: CNAME, Expected: mailgun.org, Result: ['mailgun.org.']
Hostname: e.domain.com, Type: MX, Expected: mxa.mailgun.org, Result: ['10 mxa.mailgun.org.', '10 mxb.mailgun.org.']
Hostname: e.domain.com, Type: MX, Expected: mxb.mailgun.org, Result: ['10 mxa.mailgun.org.', '10 mxb.mailgun.org.']