turn some nameserver status check errors into warnings if the domain resolves...

turn some nameserver status check errors into warnings if the domain resolves correctly since the user might be using External DNS, closes #330

CHANGELOG.md

@@ -21,6 +21,7 @@ Control panel:
 * The new check that system services are running mistakenly checked that the Dovecot Managesieve service is publicly accessible. Although the service binds to the public network interface we don't open the port in ufw. On some machines it seems that ufw blocks the connection from the status checks (which seems correct) and on some machines (mine) it doesn't, which is why I didn't notice the problem.
 * The current backup chain will now try to predict how many days until it is deleted (always at least 3 days after the next full backup).
 * The list of aliases that forward to a user are removed from the Mail Users page because when there are many alises it is slow and times-out.
+* Some status check errors are turned into warnings, especially those that might not apply if External DNS is used.
 
 v0.07 (February 28, 2015)
 -------------------------

management/status_checks.py

@@ -272,22 +272,31 @@ def check_primary_hostname_dns(domain, env, output, dns_domains, dns_zonefiles):
 			if query_dns(zone, "DS", nxdomain=None) is not None:
 				check_dnssec(zone, env, output, dns_zonefiles, is_checking_primary=True)
 
+	ip = query_dns(domain, "A")
+	ns_ips = query_dns("ns1." + domain, "A") + '/' + query_dns("ns2." + domain, "A")
+
 	# Check that the ns1/ns2 hostnames resolve to A records. This information probably
 	# comes from the TLD since the information is set at the registrar as glue records.
 	# We're probably not actually checking that here but instead checking that we, as
 	# the nameserver, are reporting the right info --- but if the glue is incorrect this
 	# will probably fail.
-	ip = query_dns("ns1." + domain, "A") + '/' + query_dns("ns2." + domain, "A")
-	if ip == env['PUBLIC_IP'] + '/' + env['PUBLIC_IP']:
+	if ns_ips == env['PUBLIC_IP'] + '/' + env['PUBLIC_IP']:
 		output.print_ok("Nameserver glue records are correct at registrar. [ns1/ns2.%s => %s]" % (env['PRIMARY_HOSTNAME'], env['PUBLIC_IP']))
+
+	elif ip == env['PUBLIC_IP']:
+		# The NS records are not what we expect, but the domain resolves correctly, so
+		# the user may have set up external DNS. List this discrepancy as a warning.
+		output.print_warning("""Nameserver glue records (ns1.%s and ns2.%s) should be configured at your domain name
+			registrar as having the IP address of this box (%s). They currently report addresses of %s. If you have set up External DNS, this may be OK."""
+			% (env['PRIMARY_HOSTNAME'], env['PRIMARY_HOSTNAME'], env['PUBLIC_IP'], ns_ips))
+
 	else:
 		output.print_error("""Nameserver glue records are incorrect. The ns1.%s and ns2.%s nameservers must be configured at your domain name
 			registrar as having the IP address %s. They currently report addresses of %s. It may take several hours for
 			public DNS to update after a change."""
-			% (env['PRIMARY_HOSTNAME'], env['PRIMARY_HOSTNAME'], env['PUBLIC_IP'], ip))
+			% (env['PRIMARY_HOSTNAME'], env['PRIMARY_HOSTNAME'], env['PUBLIC_IP'], ns_ips))
 
 	# Check that PRIMARY_HOSTNAME resolves to PUBLIC_IP in public DNS.
-	ip = query_dns(domain, "A")
 	if ip == env['PUBLIC_IP']:
 		output.print_ok("Domain resolves to box's IP address. [%s => %s]" % (env['PRIMARY_HOSTNAME'], env['PUBLIC_IP']))
 	else:
@@ -341,6 +350,7 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 	# whois information -- we may be getting the NS records from us rather than
 	# the TLD, and so we're not actually checking the TLD. For that we'd need
 	# to do a DNS trace.
+	ip = query_dns(domain, "A")
 	custom_dns = get_custom_dns_config(env)
 	existing_ns = query_dns(domain, "NS")
 	correct_ns = "; ".join(sorted([
@@ -349,6 +359,11 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 		]))
 	if existing_ns.lower() == correct_ns.lower():
 		output.print_ok("Nameservers are set correctly at registrar. [%s]" % correct_ns)
+	elif ip == env['PUBLIC_IP']:
+		# The domain resolves correctly, so maybe the user is using External DNS.
+		output.print_warning("""The nameservers set on this domain at your domain name registrar should be %s. They are currently %s.
+			If you are using External DNS, this may be OK."""
+				% (correct_ns, existing_ns) )
 	else:
 		output.print_error("""The nameservers set on this domain are incorrect. They are currently %s. Use your domain name registrar's
 			control panel to set the nameservers to %s."""