From 7172afa4a25bdb80199c4fe0628e7fb5c978ac78 Mon Sep 17 00:00:00 2001
From: Eric van der Vlist <vdv@dyomedea.com>
Date: Sat, 18 Apr 2020 09:36:48 +0200
Subject: [PATCH] Support of Docker host names (for NSD)

---
 binder/backends/nsd.py |  9 ++++-----
 binder/helpers.py      | 14 ++++++++++++++
 binder/models.py       |  4 +++-
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/binder/backends/nsd.py b/binder/backends/nsd.py
index 684c823..f7b3ef6 100644
--- a/binder/backends/nsd.py
+++ b/binder/backends/nsd.py
@@ -5,6 +5,7 @@ from django.conf import settings
 from jinja2 import Template
 import re
 import subprocess
+from binder import helpers
 
 NSD_CONF_TEMPLATE = """
 # nsd.conf for {{hostname}}
@@ -16,9 +17,7 @@ remote-control:
 
 """
 
-ZONE_RE = re.compile("""
-zone\:\s+(?P<zone_name>\S+)
-\s+state: master""")
+ZONE_RE = re.compile("""zone:\s+(?P<zone_name>\S+)\s+state:\s+master""")
 
 class NSDServer(object):
     """Class to manage NSD backend server data."""
@@ -53,13 +52,13 @@ class NSDServer(object):
             zs_out = subprocess.check_output(
                 ["/usr/sbin/nsd-control",
                 "-c", self.get_config_path(),
-                "-s", self.hostname,
+                "-s", helpers.ip_address(self.hostname),
                 "zonestatus"],
                 stderr=subprocess.STDOUT,
             ).decode('utf-8')
         except subprocess.CalledProcessError:
             raise
-        zones = ZONE_RE.findall(zs_out, re.MULTILINE)
+        zones = ZONE_RE.findall(zs_out)
         zone_data = {}
         zone_data['stats'] = {}
         zone_data['stats']['zone_stats'] = {}
diff --git a/binder/helpers.py b/binder/helpers.py
index 18f0439..2d8f218 100644
--- a/binder/helpers.py
+++ b/binder/helpers.py
@@ -175,6 +175,20 @@ def ip_info(host_name):
 
     return info
 
+def ip_address(host_name):
+    """Find an IP address for a host.
+    """
+    try:
+        for s_family, s_type, s_proto, s_cannoname, s_sockaddr in socket.getaddrinfo(host_name, None):
+            if s_family == 2 and s_type == 1:
+                return s_sockaddr[0]
+            if s_family == 10 and s_type == 1:
+                return s_sockaddr[0]
+    except (socket.gaierror, err):
+        return None
+
+    return None
+
 
 def send_dns_update(dns_message, dns_server, port, key_name):
     """Send DNS message to server and return response.
diff --git a/binder/models.py b/binder/models.py
index bf7317d..8e93a1c 100644
--- a/binder/models.py
+++ b/binder/models.py
@@ -20,6 +20,8 @@ from binder.backends import nsd
 from django.db import models
 from django.conf import settings
 from django.core.validators import MinValueValidator, MaxValueValidator
+from binder import helpers
+
 
 TSIG_ALGORITHMS = (('HMAC-MD5.SIG-ALG.REG.INT', 'MD5'),
                    ('hmac-sha1', 'SHA1'),
@@ -198,7 +200,7 @@ class BindServer(models.Model):
 
         try:
             xfr = dns.query.xfr(
-                self.hostname,
+                helpers.ip_address(self.hostname),
                 zone_name,
                 port=self.dns_port,
                 keyring=keyring,