From 7fa4862f1a125702947ae7ac64efea2946e8ec61 Mon Sep 17 00:00:00 2001
From: Joshua Tauberer <jt@occams.info>
Date: Wed, 4 Jun 2014 19:00:31 -0400
Subject: [PATCH] refactor dns_update so that the zone is first generated in a
 file-format agnostic way

---
 management/dns_update.py | 72 ++++++++++++++++++++++------------------
 1 file changed, 40 insertions(+), 32 deletions(-)

diff --git a/management/dns_update.py b/management/dns_update.py
index b7000a5c..63a06f34 100755
--- a/management/dns_update.py
+++ b/management/dns_update.py
@@ -25,7 +25,8 @@ def do_dns_update(env):
 	os.makedirs('/etc/nsd/zones', exist_ok=True)
 	updated_domains = []
 	for domain, zonefile in zonefiles:
-		if write_nsd_zone(domain, "/etc/nsd/zones/" + zonefile, env):
+		records = build_zone(domain, env)
+		if write_nsd_zone(domain, "/etc/nsd/zones/" + zonefile, records, env):
 			updated_domains.append(domain)
 
 	# Write the main nsd.conf file.
@@ -45,7 +46,37 @@ def do_dns_update(env):
 
 ########################################################################
 
-def write_nsd_zone(domain, zonefile, env):
+def build_zone(domain, env):
+	records = []
+	records.append((None,  "NS",  "ns1.%s." % env["PUBLIC_HOSTNAME"]))
+	records.append((None,  "NS",  "ns2.%s." % env["PUBLIC_HOSTNAME"]))
+	records.append((None,  "A",   env["PUBLIC_IP"]))
+	records.append((None,  "MX",  "10 %s." % env["PUBLIC_HOSTNAME"]))
+	records.append((None,  "TXT", '"v=spf1 mx -all"'))
+	records.append(("www", "A",   env["PUBLIC_IP"]))
+
+	# In PUBLIC_HOSTNAME, also define ns1 and ns2.
+	if domain == env["PUBLIC_HOSTNAME"]:
+		records.append(("ns1", "A",   env["PUBLIC_IP"]))
+		records.append(("ns2", "A",   env["PUBLIC_IP"]))
+
+	# If OpenDKIM is in use..
+	opendkim_record_file = os.path.join(env['STORAGE_ROOT'], 'mail/dkim/mail.txt')
+	if os.path.exists(opendkim_record_file):
+		# Append the DKIM TXT record to the zone as generated by OpenDKIM, after string formatting above.
+		with open(opendkim_record_file) as orf:
+			m = re.match(r"(\S+)\s+IN\s+TXT\s+(\(.*\))\s*;", orf.read(), re.S)
+			records.append((m.group(1), "TXT", m.group(2)))
+
+		# Append ADSP (RFC 5617) and DMARC records.
+		records.append(("_adsp._domainkey", "TXT", '"dkim=all"'))
+		records.append(("_dmarc", "TXT", '"v=DMARC1; p=quarantine"'))
+
+	return records
+
+########################################################################
+
+def write_nsd_zone(domain, zonefile, records, env):
 	# We set the administrative email address for every domain to domain_contact@[domain.com].
 	# You should probably create an alias to your email address.
 
@@ -60,39 +91,17 @@ $TTL 86400           ; default time to live
            864000      ; Expire
            86400       ; Min TTL
            )
-
-           NS          ns1.{primary_domain}.
-           NS          ns2.{primary_domain}.
-           IN     A    {ip}
-           MX     10   {primary_domain}.
-
-           300    TXT  "v=spf1 mx -all"
-
-www        IN     A    {ip}
-"""
-
-	# In PUBLIC_HOSTNAME, also define ns1 and ns2.
-	if domain == env["PUBLIC_HOSTNAME"]:
-		zone += """
-ns1        IN     A    {ip}
-ns2        IN     A    {ip}
 """
 
 	# Replace replacement strings.
-	zone = zone.format(domain=domain, primary_domain=env["PUBLIC_HOSTNAME"], ip=env["PUBLIC_IP"])
+	zone = zone.format(domain=domain, primary_domain=env["PUBLIC_HOSTNAME"])
 
-	# If OpenDKIM is in use..
-	opendkim_record_file = os.path.join(env['STORAGE_ROOT'], 'mail/dkim/mail.txt')
-	if os.path.exists(opendkim_record_file):
-		# Append the DKIM TXT record to the zone as generated by OpenDKIM, after string formatting above.
-		with open(opendkim_record_file) as orf:
-			zone += orf.read()
-
-		# Append ADSP (RFC 5617) and DMARC records.
-		zone += """
-_adsp._domainkey	IN	TXT	"dkim=all"
-_dmarc			IN	TXT	"v=DMARC1; p=quarantine"
-"""
+	# Add records.
+	for subdomain, querytype, value in records:
+		if subdomain:
+			zone += subdomain
+		zone += "\tIN\t" + querytype + "\t"
+		zone += value + "\n"
 
 	# Set the serial number.
 	serial = time.strftime("%Y%m%d00")
@@ -177,4 +186,3 @@ def write_opendkim_tables(zonefiles, env):
 			for domain, zonefile in zonefiles
 		))
 
-