1 files changed, 28 insertions, 0 deletions
diff --git a/nixos/tests/mosquitto.nix b/nixos/tests/mosquitto.nix
index 36cc8e3e3d9bd..d516d3373d9f6 100644
--- a/nixos/tests/mosquitto.nix
+++ b/nixos/tests/mosquitto.nix
@@ -4,6 +4,7 @@ let
   port = 1888;
   tlsPort = 1889;
   anonPort = 1890;
+  bindTestPort = 1891;
   password = "VERY_secret";
   hashedPassword = "$7$101$/WJc4Mp+I+uYE9sR$o7z9rD1EYXHPwEP5GqQj6A7k4W1yVbePlb8TqNcuOLV9WNCiDgwHOB0JHC1WCtdkssqTBduBNUnUGd6kmZvDSw==";
   topic = "test/foo";
@@ -125,6 +126,10 @@ in {
               };
             };
           }
+          {
+            settings.bind_interface = "eth0";
+            port = bindTestPort;
+          }
         ];
       };
     };
@@ -134,6 +139,8 @@ in {
   };
 
   testScript = ''
+    import json
+
     def mosquitto_cmd(binary, user, topic, port):
         return (
             "mosquitto_{} "
@@ -162,6 +169,27 @@ in {
     start_all()
     server.wait_for_unit("mosquitto.service")
 
+    with subtest("bind_interface"):
+        addrs = dict()
+        for iface in json.loads(server.succeed("ip -json address show")):
+            for addr in iface['addr_info']:
+                # don't want to deal with multihoming here
+                assert addr['local'] not in addrs
+                addrs[addr['local']] = (iface['ifname'], addr['family'])
+
+        # mosquitto grabs *one* random address per type for bind_interface
+        (has4, has6) = (False, False)
+        for line in server.succeed("ss -HlptnO sport = ${toString bindTestPort}").splitlines():
+            items = line.split()
+            if "mosquitto" not in items[5]: continue
+            listener = items[3].rsplit(':', maxsplit=1)[0].strip('[]')
+            assert listener in addrs
+            assert addrs[listener][0] == "eth0"
+            has4 |= addrs[listener][1] == 'inet'
+            has6 |= addrs[listener][1] == 'inet6'
+        assert has4
+        assert has6
+
     with subtest("check passwords"):
         client1.succeed(publish("-m test", "password_store"))
         client1.succeed(publish("-m test", "password_file"))