Automatically select among default vhosts if we have a port preference in nginx (#5944)

* automatically select among default vhosts if we have a port preference

* ports should be strings in the nginx plugin

* clarify port vs preferred_port behavior by adding allow_port_mismatch flag

* update all instances of default_vhosts to all_default_vhosts

* require port

* port should never be None in _get_default_vhost

certbot-nginx/certbot_nginx/configurator.py

@@ -289,7 +289,8 @@ class NginxConfigurator(common.Installer):
         if not vhosts:
             if create_if_no_match:
                 # result will not be [None] because it errors on failure
-                vhosts = [self._vhost_from_duplicated_default(target_name)]
+                vhosts = [self._vhost_from_duplicated_default(target_name, True,
+                    str(self.config.tls_sni_01_port))]
             else:
                 # No matches. Raise a misconfiguration error.
                 raise errors.MisconfigurationError(
@@ -332,9 +333,12 @@ class NginxConfigurator(common.Installer):
                     ipv6only_present = True
         return (ipv6_active, ipv6only_present)
 
-    def _vhost_from_duplicated_default(self, domain, port=None):
+    def _vhost_from_duplicated_default(self, domain, allow_port_mismatch, port):
+        """if allow_port_mismatch is False, only server blocks with matching ports will be
+           used as a default server block template.
+        """
         if self.new_vhost is None:
-            default_vhost = self._get_default_vhost(port, domain)
+            default_vhost = self._get_default_vhost(domain, allow_port_mismatch, port)
             self.new_vhost = self.parser.duplicate_vhost(default_vhost,
                 remove_singleton_listen_params=True)
             self.new_vhost.names = set()
@@ -350,19 +354,24 @@ class NginxConfigurator(common.Installer):
             name_block[0].append(name)
         self.parser.update_or_add_server_directives(vhost, name_block)
 
-    def _get_default_vhost(self, port, domain):
+    def _get_default_vhost(self, domain, allow_port_mismatch, port):
+        """Helper method for _vhost_from_duplicated_default; see argument documentation there"""
         vhost_list = self.parser.get_vhosts()
         # if one has default_server set, return that one
-        default_vhosts = []
+        all_default_vhosts = []
+        port_matching_vhosts = []
         for vhost in vhost_list:
             for addr in vhost.addrs:
                 if addr.default:
-                    if port is None or self._port_matches(port, addr.get_port()):
-                        default_vhosts.append(vhost)
-                        break
+                    all_default_vhosts.append(vhost)
+                    if self._port_matches(port, addr.get_port()):
+                        port_matching_vhosts.append(vhost)
+                    break
 
-        if len(default_vhosts) == 1:
-            return default_vhosts[0]
+        if len(port_matching_vhosts) == 1:
+            return port_matching_vhosts[0]
+        elif len(all_default_vhosts) == 1 and allow_port_mismatch:
+            return all_default_vhosts[0]
 
         # TODO: present a list of vhosts for user to choose from
 
@@ -471,7 +480,7 @@ class NginxConfigurator(common.Installer):
             matches = self._get_redirect_ranked_matches(target_name, port)
             vhosts = [x for x in [self._select_best_name_match(matches)]if x is not None]
         if not vhosts and create_if_no_match:
-            vhosts = [self._vhost_from_duplicated_default(target_name, port=port)]
+            vhosts = [self._vhost_from_duplicated_default(target_name, False, port)]
         return vhosts
 
     def _port_matches(self, test_port, matching_port):

certbot-nginx/certbot_nginx/tests/configurator_test.py

@@ -731,6 +731,13 @@ class NginxConfiguratorTest(util.NginxTest):
             "www.nomatch.com", "example/cert.pem", "example/key.pem",
             "example/chain.pem", "example/fullchain.pem")
 
+    def test_deploy_no_match_multiple_defaults_ok(self):
+        foo_conf = self.config.parser.abs_path('foo.conf')
+        self.config.parser.parsed[foo_conf][2][1][0][1][0][1] = '*:5001'
+        self.config.version = (1, 3, 1)
+        self.config.deploy_cert("www.nomatch.com", "example/cert.pem", "example/key.pem",
+            "example/chain.pem", "example/fullchain.pem")
+
     def test_deploy_no_match_add_redirect(self):
         default_conf = self.config.parser.abs_path('sites-enabled/default')
         foo_conf = self.config.parser.abs_path('foo.conf')