3 - docker

Dockerfile

@@ -0,0 +1,9 @@
+FROM python:3.11-slim-bookworm
+
+WORKDIR /app 
+
+COPY main.py requirements.txt /app
+
+RUN pip3 install -r requirements.txt --no-cache-dir
+
+ENTRYPOINT ["python3", "main.py"]

README.md

@@ -0,0 +1,7 @@
+### Build an image
+
+docker build . -t dns-watcher
+
+### Run a container
+
+docker run --rm --env DOMAINS_LIST_PATH=/app/domains.yaml --env DNS_SERVER=1.1.1.1 --env RESOLUTION_PROTOCOL=UDP --volume ./domains.yaml:/app/domains.yaml dns-watcher

main.py

@@ -1,12 +1,65 @@
 import sys
 import warnings
 import os
+import dns.message
+import dns.name
+import dns.query
+import dns.rdata
+import dns.rrset
 import requests
+import random
 from urllib.parse import urlparse
+from urllib3.util import connection
 
 warnings.filterwarnings("ignore")
 
 domains_list_path = os.environ.get('DOMAINS_LIST_PATH', './domains.yaml')
+dns_server = os.environ.get('DNS_SERVER', '1.1.1.1')
+resolution_protocol = os.environ.get('RESOLUTION_PROTOCOL', 'UDP')
+timeout = 5
+
+def resolve(host):
+    ips = []
+    hosts = [host]
+    while len(hosts) > 0:
+        next_host = hosts.pop()
+        try:
+            name = dns.name.from_text(next_host)
+            query = dns.message.make_query(name, dns.rdatatype.A)
+            match resolution_protocol:
+                case 'UDP':
+                    response = dns.query.udp(query, dns_server, timeout)
+                case 'HTTPS':
+                    response = dns.query.https(query, dns_server, timeout)
+            answers = response.answer
+            for answer in answers:
+                for record in answer:
+                    address = record.to_text()
+                    if address[len(address) - 1] != ".":
+                        ips.append(record.to_text())
+                    else:
+                        hosts.append(address)
+        except:
+            pass
+    print("debug: host '{0}' has been resolved via {1} using {2} into the following addresses: {3}".format(host, dns_server, resolution_protocol, ips))
+    return ips
+
+create_connection_original = connection.create_connection
+
+def create_connection_patched(address, *args, **kwargs):
+    host, port = address
+    ips = resolve(host)
+    if len(ips) > 0:
+        ip = ips[random.randint(0, len(ips) - 1)]
+        print("debug: {0} will be used".format(ip))
+        return create_connection_original((ip, port), *args, **kwargs)
+    else:
+        raise Exception()
+
+connection.create_connection = create_connection_patched
+
+session = requests.Session()
+session.trust_env = False
 
 try:
     domains_list = open(domains_list_path, 'r')
@@ -16,10 +69,9 @@
     sys.exit(1)
 
 for domain in domains:
-    print(domain)
     try:
-        request = requests.get('https://' + domain, verify=False) 
-        final_domain = urlparse(request.url).netloc
-        print("\t" + final_domain)
+        response = session.get('http://' + domain, verify=False) 
+        final_domain = urlparse(response.url).netloc
     except:
-        print()
+        pass
+    print()

requirements.txt

@@ -0,0 +1,14 @@
+anyio==4.3.0
+certifi==2024.2.2
+charset-normalizer==3.3.2
+dnspython==2.6.1
+h11==0.14.0
+h2==4.1.0
+hpack==4.0.0
+httpcore==1.0.5
+httpx==0.27.0
+hyperframe==6.0.1
+idna==3.6
+requests==2.31.0
+sniffio==1.3.1
+urllib3==2.2.1