From 7dad37ed04ec7e85b0a64ee22629528e892628e7 Mon Sep 17 00:00:00 2001
From: Alexandre Aubin <alex.aubin@mailoo.org>
Date: Mon, 18 Jan 2021 19:57:31 +0100
Subject: [PATCH 1/4] Make dyndns update more resilient to ns0.yunohost.org
 being down

---
 src/yunohost/dyndns.py | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/yunohost/dyndns.py b/src/yunohost/dyndns.py
index fe2a1bc9b..98d59721a 100644
--- a/src/yunohost/dyndns.py
+++ b/src/yunohost/dyndns.py
@@ -34,7 +34,7 @@ from moulinette import m18n
 from moulinette.core import MoulinetteError
 from moulinette.utils.log import getActionLogger
 from moulinette.utils.filesystem import write_to_file, read_file
-from moulinette.utils.network import download_json
+from moulinette.utils.network import download_json, dig
 from moulinette.utils.process import check_output
 
 from yunohost.utils.error import YunohostError
@@ -216,8 +216,30 @@ def dyndns_update(operation_logger, dyn_host="dyndns.yunohost.org", domain=None,
         'zone %s' % host,
     ]
 
-    old_ipv4 = check_output("dig @%s +short %s" % (dyn_host, domain)) or None
-    old_ipv6 = check_output("dig @%s +short aaaa %s" % (dyn_host, domain)) or None
+
+    def resolve_domain(domain, rdtype):
+
+        ok, result = dig(domain, rdtype, resolvers=[dyn_host])
+        if ok == "ok":
+            return result[0] if len(result) else None
+        elif result[0] == "Timeout":
+            logger.debug("Timed-out while trying to resolve %s record for %s using %s" % (rdtype, domain, dyn_host))
+        else:
+            return None
+
+        logger.debug("Falling back to external resolvers")
+        ok, result = dig(domain, rdtype, resolvers="force_external")
+        if ok == "ok":
+            return result[0] if len(result) else None
+        elif result[0] == "Timeout":
+            logger.debug("Timed-out while trying to resolve %s record for %s using external resolvers : %s" % (rdtype, domain, result))
+        else:
+            return None
+
+        raise YunohostError("Failed to resolve %s for %s" % (rdtype, domain), raw_msg=True)
+
+    old_ipv4 = resolve_domain(domain, "A")
+    old_ipv6 = resolve_domain(domain, "AAAA")
 
     # Get current IPv4 and IPv6
     ipv4_ = get_public_ip()

From d5403e5f5f3158fb51f741d6a49b13c3a9641ddc Mon Sep 17 00:00:00 2001
From: Alexandre Aubin <alex.aubin@mailoo.org>
Date: Mon, 18 Jan 2021 20:25:36 +0100
Subject: [PATCH 2/4] Typo

---
 src/yunohost/dyndns.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/yunohost/dyndns.py b/src/yunohost/dyndns.py
index 98d59721a..eb03b056e 100644
--- a/src/yunohost/dyndns.py
+++ b/src/yunohost/dyndns.py
@@ -34,12 +34,12 @@ from moulinette import m18n
 from moulinette.core import MoulinetteError
 from moulinette.utils.log import getActionLogger
 from moulinette.utils.filesystem import write_to_file, read_file
-from moulinette.utils.network import download_json, dig
+from moulinette.utils.network import download_json
 from moulinette.utils.process import check_output
 
 from yunohost.utils.error import YunohostError
 from yunohost.domain import _get_maindomain, _build_dns_conf
-from yunohost.utils.network import get_public_ip
+from yunohost.utils.network import get_public_ip, dig
 from yunohost.log import is_unit_operation
 
 logger = getActionLogger('yunohost.dyndns')

From e7300859704c9f815d79f7b1ac63cb813d52120b Mon Sep 17 00:00:00 2001
From: Alexandre Aubin <alex.aubin@mailoo.org>
Date: Mon, 18 Jan 2021 20:53:38 +0100
Subject: [PATCH 3/4] Linter is angry about unused import

---
 src/yunohost/dyndns.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/yunohost/dyndns.py b/src/yunohost/dyndns.py
index eb03b056e..84b55d40e 100644
--- a/src/yunohost/dyndns.py
+++ b/src/yunohost/dyndns.py
@@ -35,7 +35,6 @@ from moulinette.core import MoulinetteError
 from moulinette.utils.log import getActionLogger
 from moulinette.utils.filesystem import write_to_file, read_file
 from moulinette.utils.network import download_json
-from moulinette.utils.process import check_output
 
 from yunohost.utils.error import YunohostError
 from yunohost.domain import _get_maindomain, _build_dns_conf

From 8b05248ad45bfe05ae9205e976798a4e722eaee9 Mon Sep 17 00:00:00 2001
From: Alexandre Aubin <alex.aubin@mailoo.org>
Date: Tue, 19 Jan 2021 02:34:28 +0100
Subject: [PATCH 4/4] Turns out we need to feed the IP of the resolver and
 can't use the doman name :/

---
 src/yunohost/dyndns.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/yunohost/dyndns.py b/src/yunohost/dyndns.py
index 84b55d40e..9904d3955 100644
--- a/src/yunohost/dyndns.py
+++ b/src/yunohost/dyndns.py
@@ -218,7 +218,13 @@ def dyndns_update(operation_logger, dyn_host="dyndns.yunohost.org", domain=None,
 
     def resolve_domain(domain, rdtype):
 
-        ok, result = dig(domain, rdtype, resolvers=[dyn_host])
+        # FIXME make this work for IPv6-only hosts too..
+        ok, result = dig(dyn_host, "A")
+        dyn_host_ip = result[0] if ok == "ok" and len(result) else None
+        if not dyn_host_ip:
+            raise YunohostError("Failed to resolve %s" % dyn_host)
+     
+        ok, result = dig(domain, rdtype, resolvers=[dyn_host_ip])
         if ok == "ok":
             return result[0] if len(result) else None
         elif result[0] == "Timeout":