From 63f1758f28e623c836624025099f0dd82741c360 Mon Sep 17 00:00:00 2001
From: Aarni Koskela <akx@iki.fi>
Date: Sun, 24 Dec 2023 13:29:06 +0200
Subject: [PATCH] Allow running tests in parallel (don't reuse addresses)

---
 tests/lib/clients/01-asyncio.py               |  4 +-
 tests/lib/clients/01-decorators.py            |  4 +-
 tests/lib/clients/01-keepalive-pingreq.py     |  4 +-
 tests/lib/clients/01-no-clean-session.py      |  4 +-
 tests/lib/clients/01-reconnect-on-failure.py  |  4 +-
 .../clients/01-unpwd-empty-password-set.py    |  4 +-
 tests/lib/clients/01-unpwd-empty-set.py       |  4 +-
 tests/lib/clients/01-unpwd-set.py             |  4 +-
 tests/lib/clients/01-unpwd-unicode-set.py     |  4 +-
 tests/lib/clients/01-will-set.py              |  4 +-
 tests/lib/clients/01-will-unpwd-set.py        |  4 +-
 tests/lib/clients/01-zero-length-clientid.py  |  4 +-
 tests/lib/clients/02-subscribe-qos0.py        |  4 +-
 tests/lib/clients/02-subscribe-qos1.py        |  4 +-
 tests/lib/clients/02-subscribe-qos2.py        |  4 +-
 tests/lib/clients/02-unsubscribe.py           |  4 +-
 tests/lib/clients/03-publish-b2c-qos1.py      |  4 +-
 tests/lib/clients/03-publish-b2c-qos2.py      |  4 +-
 .../clients/03-publish-c2b-qos1-disconnect.py |  4 +-
 .../clients/03-publish-c2b-qos2-disconnect.py |  4 +-
 .../lib/clients/03-publish-helper-qos0-v5.py  |  4 +-
 tests/lib/clients/03-publish-helper-qos0.py   |  4 +-
 .../03-publish-helper-qos1-disconnect.py      |  4 +-
 .../lib/clients/03-publish-qos0-no-payload.py |  4 +-
 tests/lib/clients/03-publish-qos0.py          |  4 +-
 tests/lib/clients/04-retain-qos0.py           |  4 +-
 .../clients/08-ssl-connect-cert-auth-pw.py    |  4 +-
 tests/lib/clients/08-ssl-connect-cert-auth.py |  4 +-
 tests/lib/clients/08-ssl-connect-no-auth.py   |  4 +-
 tests/lib/clients/08-ssl-fake-cacert.py       |  4 +-
 tests/lib/conftest.py                         | 11 ++--
 tests/lib/test_01_keepalive_pingreq.py        |  2 +-
 tests/lib/test_01_no_clean_session.py         |  2 +-
 tests/lib/test_01_unpwd_empty_password_set.py |  2 +-
 tests/lib/test_01_unpwd_empty_set.py          |  2 +-
 tests/lib/test_01_unpwd_set.py                |  2 +-
 tests/lib/test_01_unpwd_unicode_set.py        |  2 +-
 tests/lib/test_01_will_set.py                 |  2 +-
 tests/lib/test_01_will_unpwd_set.py           |  2 +-
 tests/lib/test_02_subscribe_qos0.py           |  2 +-
 tests/lib/test_02_subscribe_qos1.py           |  2 +-
 tests/lib/test_02_subscribe_qos2.py           |  2 +-
 tests/lib/test_03_publish_b2c_qos1.py         |  2 +-
 tests/lib/test_03_publish_helper_qos0.py      |  2 +-
 tests/lib/test_03_publish_helper_qos0_v5.py   |  2 +-
 tests/lib/test_03_publish_qos0.py             |  2 +-
 tests/lib/test_03_publish_qos0_no_payload.py  |  2 +-
 tests/lib/test_08_ssl_connect_cert_auth.py    |  2 +-
 tests/lib/test_08_ssl_connect_cert_auth_pw.py |  2 +-
 tests/lib/test_08_ssl_connect_no_auth.py      |  2 +-
 tests/paho_test.py                            | 53 +++++++++----------
 tests/test_client.py                          | 12 ++---
 tests/test_websocket_integration.py           | 12 ++---
 tests/testsupport/broker.py                   | 10 ++--
 54 files changed, 128 insertions(+), 128 deletions(-)

diff --git a/tests/lib/clients/01-asyncio.py b/tests/lib/clients/01-asyncio.py
index 30375ffe..05f3cf55 100644
--- a/tests/lib/clients/01-asyncio.py
+++ b/tests/lib/clients/01-asyncio.py
@@ -3,6 +3,8 @@
 
 import paho.mqtt.client as mqtt
 
+from tests.paho_test import get_test_server_port
+
 client_id = 'asyncio-test'
 
 
@@ -78,7 +80,7 @@ def on_disconnect(client, userdata, rc):
 
     aioh = AsyncioHelper(loop, client)
 
-    client.connect('localhost', 1888, 60)
+    client.connect('localhost', get_test_server_port(), 60)
     client.socket().setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 2048)
 
     await disconnected
diff --git a/tests/lib/clients/01-decorators.py b/tests/lib/clients/01-decorators.py
index ffb3cf24..03d1a32a 100644
--- a/tests/lib/clients/01-decorators.py
+++ b/tests/lib/clients/01-decorators.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("decorators-test", clean_session=True)
 payload = b""
@@ -38,5 +38,5 @@ def on_disconnect(mqttc, obj, rc):
     obj = rc
 
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-keepalive-pingreq.py b/tests/lib/clients/01-keepalive-pingreq.py
index ec0c9573..e6ab8545 100644
--- a/tests/lib/clients/01-keepalive-pingreq.py
+++ b/tests/lib/clients/01-keepalive-pingreq.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -10,5 +10,5 @@ def on_connect(mqttc, obj, flags, rc):
 mqttc = mqtt.Client("01-keepalive-pingreq")
 mqttc.on_connect = on_connect
 
-mqttc.connect("localhost", 1888, keepalive=4)
+mqttc.connect("localhost", get_test_server_port(), keepalive=4)
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-no-clean-session.py b/tests/lib/clients/01-no-clean-session.py
index c8ed09c5..a620ef99 100644
--- a/tests/lib/clients/01-no-clean-session.py
+++ b/tests/lib/clients/01-no-clean-session.py
@@ -1,8 +1,8 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-no-clean-session", clean_session=False)
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-reconnect-on-failure.py b/tests/lib/clients/01-reconnect-on-failure.py
index 0cb88bee..afbd3b77 100644
--- a/tests/lib/clients/01-reconnect-on-failure.py
+++ b/tests/lib/clients/01-reconnect-on-failure.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -11,6 +11,6 @@ def on_connect(mqttc, obj, flags, rc):
 mqttc.on_connect = on_connect
 
 with wait_for_keyboard_interrupt():
-    mqttc.connect("localhost", 1888)
+    mqttc.connect("localhost", get_test_server_port())
     mqttc.loop_forever()
     exit(42)  # this is expected by the test case
diff --git a/tests/lib/clients/01-unpwd-empty-password-set.py b/tests/lib/clients/01-unpwd-empty-password-set.py
index c22083eb..c1115800 100644
--- a/tests/lib/clients/01-unpwd-empty-password-set.py
+++ b/tests/lib/clients/01-unpwd-empty-password-set.py
@@ -1,9 +1,9 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-unpwd-set")
 
 mqttc.username_pw_set("uname", "")
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-unpwd-empty-set.py b/tests/lib/clients/01-unpwd-empty-set.py
index 1a5284a3..300c18a1 100644
--- a/tests/lib/clients/01-unpwd-empty-set.py
+++ b/tests/lib/clients/01-unpwd-empty-set.py
@@ -1,9 +1,9 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-unpwd-set")
 
 mqttc.username_pw_set("", "")
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-unpwd-set.py b/tests/lib/clients/01-unpwd-set.py
index e34db561..a872a28c 100644
--- a/tests/lib/clients/01-unpwd-set.py
+++ b/tests/lib/clients/01-unpwd-set.py
@@ -1,9 +1,9 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-unpwd-set")
 
 mqttc.username_pw_set("uname", ";'[08gn=#")
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-unpwd-unicode-set.py b/tests/lib/clients/01-unpwd-unicode-set.py
index c3ffc40e..707ea787 100644
--- a/tests/lib/clients/01-unpwd-unicode-set.py
+++ b/tests/lib/clients/01-unpwd-unicode-set.py
@@ -2,12 +2,12 @@
 
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-unpwd-unicode-set")
 
 username = "\u00fas\u00e9rn\u00e1m\u00e9-h\u00e9ll\u00f3"
 password = "h\u00e9ll\u00f3"
 mqttc.username_pw_set(username, password)
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-will-set.py b/tests/lib/clients/01-will-set.py
index 5a1f76d1..b273da32 100644
--- a/tests/lib/clients/01-will-set.py
+++ b/tests/lib/clients/01-will-set.py
@@ -1,9 +1,9 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-will-set")
 
 mqttc.will_set("topic/on/unexpected/disconnect", "will message", 1, True)
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-will-unpwd-set.py b/tests/lib/clients/01-will-unpwd-set.py
index c88adc08..3510716e 100644
--- a/tests/lib/clients/01-will-unpwd-set.py
+++ b/tests/lib/clients/01-will-unpwd-set.py
@@ -1,10 +1,10 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 mqttc = mqtt.Client("01-will-unpwd-set")
 
 mqttc.username_pw_set("oibvvwqw", "#'^2hg9a&nm38*us")
 mqttc.will_set("will-topic", "will message", 2, False)
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/01-zero-length-clientid.py b/tests/lib/clients/01-zero-length-clientid.py
index b1809733..672628ad 100644
--- a/tests/lib/clients/01-zero-length-clientid.py
+++ b/tests/lib/clients/01-zero-length-clientid.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -17,5 +17,5 @@ def on_disconnect(mqttc, obj, rc):
 mqttc.on_connect = on_connect
 mqttc.on_disconnect = on_disconnect
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/02-subscribe-qos0.py b/tests/lib/clients/02-subscribe-qos0.py
index f5411d9d..b55fb54f 100644
--- a/tests/lib/clients/02-subscribe-qos0.py
+++ b/tests/lib/clients/02-subscribe-qos0.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -21,5 +21,5 @@ def on_subscribe(mqttc, obj, mid, granted_qos):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_subscribe = on_subscribe
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/02-subscribe-qos1.py b/tests/lib/clients/02-subscribe-qos1.py
index 27792aa3..063eee90 100644
--- a/tests/lib/clients/02-subscribe-qos1.py
+++ b/tests/lib/clients/02-subscribe-qos1.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -21,5 +21,5 @@ def on_subscribe(mqttc, obj, mid, granted_qos):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_subscribe = on_subscribe
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/02-subscribe-qos2.py b/tests/lib/clients/02-subscribe-qos2.py
index 45225b24..47a9e159 100644
--- a/tests/lib/clients/02-subscribe-qos2.py
+++ b/tests/lib/clients/02-subscribe-qos2.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -21,5 +21,5 @@ def on_subscribe(mqttc, obj, mid, granted_qos):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_subscribe = on_subscribe
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/02-unsubscribe.py b/tests/lib/clients/02-unsubscribe.py
index aa178bd8..2ed5c9b8 100644
--- a/tests/lib/clients/02-unsubscribe.py
+++ b/tests/lib/clients/02-unsubscribe.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -21,5 +21,5 @@ def on_unsubscribe(mqttc, obj, mid):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_unsubscribe = on_unsubscribe
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/03-publish-b2c-qos1.py b/tests/lib/clients/03-publish-b2c-qos1.py
index d2fe7ae4..9efc928d 100644
--- a/tests/lib/clients/03-publish-b2c-qos1.py
+++ b/tests/lib/clients/03-publish-b2c-qos1.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 expected_payload = b"message"
 
@@ -21,5 +21,5 @@ def on_connect(mqttc, obj, flags, rc):
 mqttc.on_connect = on_connect
 mqttc.on_message = on_message
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/03-publish-b2c-qos2.py b/tests/lib/clients/03-publish-b2c-qos2.py
index ba871a7f..246cb097 100644
--- a/tests/lib/clients/03-publish-b2c-qos2.py
+++ b/tests/lib/clients/03-publish-b2c-qos2.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 expected_payload = b"message"
 
@@ -21,7 +21,7 @@ def on_connect(mqttc, obj, flags, rc):
 mqttc.on_connect = on_connect
 mqttc.on_message = on_message
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 
 with wait_for_keyboard_interrupt():
     while True:
diff --git a/tests/lib/clients/03-publish-c2b-qos1-disconnect.py b/tests/lib/clients/03-publish-c2b-qos1-disconnect.py
index 8d958d36..17a0df3d 100644
--- a/tests/lib/clients/03-publish-c2b-qos1-disconnect.py
+++ b/tests/lib/clients/03-publish-c2b-qos1-disconnect.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 sent_mid = -1
 
@@ -29,5 +29,5 @@ def on_publish(mqttc, obj, mid):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_publish = on_publish
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/03-publish-c2b-qos2-disconnect.py b/tests/lib/clients/03-publish-c2b-qos2-disconnect.py
index cc66a0e4..6e0fddfe 100644
--- a/tests/lib/clients/03-publish-c2b-qos2-disconnect.py
+++ b/tests/lib/clients/03-publish-c2b-qos2-disconnect.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 first_connection = 1
 
@@ -27,5 +27,5 @@ def on_publish(mqttc, obj, mid):
 mqttc.on_disconnect = on_disconnect
 mqttc.on_publish = on_publish
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/03-publish-helper-qos0-v5.py b/tests/lib/clients/03-publish-helper-qos0-v5.py
index a011f9d9..1b59113d 100644
--- a/tests/lib/clients/03-publish-helper-qos0-v5.py
+++ b/tests/lib/clients/03-publish-helper-qos0-v5.py
@@ -1,7 +1,7 @@
 import paho.mqtt.client
 import paho.mqtt.publish
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 with wait_for_keyboard_interrupt():
     paho.mqtt.publish.single(
@@ -9,7 +9,7 @@
         "message",
         qos=0,
         hostname="localhost",
-        port=1888,
+        port=get_test_server_port(),
         client_id="publish-helper-qos0-test",
         protocol=paho.mqtt.client.MQTTv5,
     )
diff --git a/tests/lib/clients/03-publish-helper-qos0.py b/tests/lib/clients/03-publish-helper-qos0.py
index 70145196..a7b696eb 100644
--- a/tests/lib/clients/03-publish-helper-qos0.py
+++ b/tests/lib/clients/03-publish-helper-qos0.py
@@ -1,6 +1,6 @@
 import paho.mqtt.publish
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 with wait_for_keyboard_interrupt():
     paho.mqtt.publish.single(
@@ -8,6 +8,6 @@
         "message",
         qos=0,
         hostname="localhost",
-        port=1888,
+        port=get_test_server_port(),
         client_id="publish-helper-qos0-test",
     )
diff --git a/tests/lib/clients/03-publish-helper-qos1-disconnect.py b/tests/lib/clients/03-publish-helper-qos1-disconnect.py
index 88c99274..b07166f6 100644
--- a/tests/lib/clients/03-publish-helper-qos1-disconnect.py
+++ b/tests/lib/clients/03-publish-helper-qos1-disconnect.py
@@ -1,6 +1,6 @@
 import paho.mqtt.publish
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 with wait_for_keyboard_interrupt():
     paho.mqtt.publish.single(
@@ -8,6 +8,6 @@
         "message",
         qos=1,
         hostname="localhost",
-        port=1888,
+        port=get_test_server_port(),
         client_id="publish-helper-qos1-disconnect-test",
     )
diff --git a/tests/lib/clients/03-publish-qos0-no-payload.py b/tests/lib/clients/03-publish-qos0-no-payload.py
index e6bea409..37458a83 100644
--- a/tests/lib/clients/03-publish-qos0-no-payload.py
+++ b/tests/lib/clients/03-publish-qos0-no-payload.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 sent_mid = -1
 
@@ -20,5 +20,5 @@ def on_publish(mqttc, obj, mid):
 mqttc.on_connect = on_connect
 mqttc.on_publish = on_publish
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/03-publish-qos0.py b/tests/lib/clients/03-publish-qos0.py
index 60c3f6c5..85386dda 100644
--- a/tests/lib/clients/03-publish-qos0.py
+++ b/tests/lib/clients/03-publish-qos0.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 sent_mid = -1
 
@@ -22,5 +22,5 @@ def on_publish(mqttc, obj, mid):
 mqttc.on_connect = on_connect
 mqttc.on_publish = on_publish
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/04-retain-qos0.py b/tests/lib/clients/04-retain-qos0.py
index 410ee82f..b50a7381 100644
--- a/tests/lib/clients/04-retain-qos0.py
+++ b/tests/lib/clients/04-retain-qos0.py
@@ -1,6 +1,6 @@
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -11,5 +11,5 @@ def on_connect(mqttc, obj, flags, rc):
 mqttc = mqtt.Client("retain-qos0-test", clean_session=True)
 mqttc.on_connect = on_connect
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/08-ssl-connect-cert-auth-pw.py b/tests/lib/clients/08-ssl-connect-cert-auth-pw.py
index edcc00d0..7f97df5f 100644
--- a/tests/lib/clients/08-ssl-connect-cert-auth-pw.py
+++ b/tests/lib/clients/08-ssl-connect-cert-auth-pw.py
@@ -2,7 +2,7 @@
 
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -24,5 +24,5 @@ def on_disconnect(mqttc, obj, rc):
 mqttc.on_connect = on_connect
 mqttc.on_disconnect = on_disconnect
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/08-ssl-connect-cert-auth.py b/tests/lib/clients/08-ssl-connect-cert-auth.py
index 78a5bbc0..f907e38c 100644
--- a/tests/lib/clients/08-ssl-connect-cert-auth.py
+++ b/tests/lib/clients/08-ssl-connect-cert-auth.py
@@ -2,7 +2,7 @@
 
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -23,5 +23,5 @@ def on_disconnect(mqttc, obj, rc):
 mqttc.on_connect = on_connect
 mqttc.on_disconnect = on_disconnect
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/08-ssl-connect-no-auth.py b/tests/lib/clients/08-ssl-connect-no-auth.py
index cd0d1411..43c3d01f 100644
--- a/tests/lib/clients/08-ssl-connect-no-auth.py
+++ b/tests/lib/clients/08-ssl-connect-no-auth.py
@@ -2,7 +2,7 @@
 
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import loop_until_keyboard_interrupt
+from tests.paho_test import get_test_server_port, loop_until_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -19,5 +19,5 @@ def on_disconnect(mqttc, obj, rc):
 mqttc.on_connect = on_connect
 mqttc.on_disconnect = on_disconnect
 
-mqttc.connect("localhost", 1888)
+mqttc.connect("localhost", get_test_server_port())
 loop_until_keyboard_interrupt(mqttc)
diff --git a/tests/lib/clients/08-ssl-fake-cacert.py b/tests/lib/clients/08-ssl-fake-cacert.py
index e309e1bc..04b146ed 100644
--- a/tests/lib/clients/08-ssl-fake-cacert.py
+++ b/tests/lib/clients/08-ssl-fake-cacert.py
@@ -3,7 +3,7 @@
 
 import paho.mqtt.client as mqtt
 
-from tests.paho_test import wait_for_keyboard_interrupt
+from tests.paho_test import get_test_server_port, wait_for_keyboard_interrupt
 
 
 def on_connect(mqttc, obj, flags, rc):
@@ -20,7 +20,7 @@ def on_connect(mqttc, obj, flags, rc):
 
 with wait_for_keyboard_interrupt():
     try:
-        mqttc.connect("localhost", 1888)
+        mqttc.connect("localhost", get_test_server_port())
     except ssl.SSLError as msg:
         assert msg.errno == 1 and "certificate verify failed" in msg.strerror
     else:
diff --git a/tests/lib/conftest.py b/tests/lib/conftest.py
index 3e2853e8..b2be3cbf 100644
--- a/tests/lib/conftest.py
+++ b/tests/lib/conftest.py
@@ -12,8 +12,9 @@
 
 
 @pytest.fixture()
-def server_socket():
-    sock = create_server_socket()
+def server_socket(monkeypatch):
+    sock, port = create_server_socket()
+    monkeypatch.setenv("PAHO_SERVER_PORT", str(port))
     try:
         yield sock
     finally:
@@ -21,8 +22,9 @@ def server_socket():
 
 
 @pytest.fixture()
-def ssl_server_socket():
-    sock = create_server_socket_ssl()
+def ssl_server_socket(monkeypatch):
+    sock, port = create_server_socket_ssl()
+    monkeypatch.setenv("PAHO_SERVER_PORT", str(port))
     try:
         yield sock
     finally:
@@ -51,6 +53,7 @@ def starter(name: str, expected_returncode: int = 0) -> None:
             PAHO_SSL_PATH=str(ssl_path),
             PYTHONPATH=f"{tests_path}{os.pathsep}{os.environ.get('PYTHONPATH', '')}",
         )
+        assert 'PAHO_SERVER_PORT' in env, "PAHO_SERVER_PORT must be set in the environment when starting a client"
         # TODO: it would be nice to run this under `coverage` too!
         proc = subprocess.Popen([
             sys.executable,
diff --git a/tests/lib/test_01_keepalive_pingreq.py b/tests/lib/test_01_keepalive_pingreq.py
index 0560f132..4c327db3 100644
--- a/tests/lib/test_01_keepalive_pingreq.py
+++ b/tests/lib/test_01_keepalive_pingreq.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a pingreq after the keepalive time
 
-# The client should connect to port 1888 with keepalive=4, clean session set,
+# The client should connect with keepalive=4, clean session set,
 # and client id 01-keepalive-pingreq
 # The client should send a PINGREQ message after the appropriate amount of time
 # (4 seconds after no traffic).
diff --git a/tests/lib/test_01_no_clean_session.py b/tests/lib/test_01_no_clean_session.py
index 531fa12e..7f00e544 100644
--- a/tests/lib/test_01_no_clean_session.py
+++ b/tests/lib/test_01_no_clean_session.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with clean session not set.
 
-# The client should connect to port 1888 with keepalive=60, clean session not
+# The client should connect with keepalive=60, clean session not
 # set, and client id 01-no-clean-session.
 
 
diff --git a/tests/lib/test_01_unpwd_empty_password_set.py b/tests/lib/test_01_unpwd_empty_password_set.py
index 181ea00b..225d72bc 100644
--- a/tests/lib/test_01_unpwd_empty_password_set.py
+++ b/tests/lib/test_01_unpwd_empty_password_set.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with a username and password.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-unpwd-set, username set to uname and password set to empty string
 
 
diff --git a/tests/lib/test_01_unpwd_empty_set.py b/tests/lib/test_01_unpwd_empty_set.py
index 2bed58f4..8c51c22a 100644
--- a/tests/lib/test_01_unpwd_empty_set.py
+++ b/tests/lib/test_01_unpwd_empty_set.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with a username and password.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-unpwd-set, username and password set to empty string.
 
 
diff --git a/tests/lib/test_01_unpwd_set.py b/tests/lib/test_01_unpwd_set.py
index 6f67f947..38834ab9 100644
--- a/tests/lib/test_01_unpwd_set.py
+++ b/tests/lib/test_01_unpwd_set.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with a username and password.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-unpwd-set, username set to uname and password set to ;'[08gn=#
 
 
diff --git a/tests/lib/test_01_unpwd_unicode_set.py b/tests/lib/test_01_unpwd_unicode_set.py
index ed9c0074..875e00bf 100644
--- a/tests/lib/test_01_unpwd_unicode_set.py
+++ b/tests/lib/test_01_unpwd_unicode_set.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with a unicode username and password.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-unpwd-unicode-set, username and password from corresponding variables
 
 from __future__ import unicode_literals
diff --git a/tests/lib/test_01_will_set.py b/tests/lib/test_01_will_set.py
index 7da70862..55b55a25 100644
--- a/tests/lib/test_01_will_set.py
+++ b/tests/lib/test_01_will_set.py
@@ -1,7 +1,7 @@
 # Test whether a client produces a correct connect with a will.
 # Will QoS=1, will retain=1.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-will-set will topic set to topic/on/unexpected/disconnect , will
 # payload set to "will message", will qos set to 1 and will retain set.
 
diff --git a/tests/lib/test_01_will_unpwd_set.py b/tests/lib/test_01_will_unpwd_set.py
index 4c7ea36a..95c0517f 100644
--- a/tests/lib/test_01_will_unpwd_set.py
+++ b/tests/lib/test_01_will_unpwd_set.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect with a will, username and password.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # client id 01-will-unpwd-set , will topic set to "will-topic", will payload
 # set to "will message", will qos=2, will retain not set, username set to
 # "oibvvwqw" and password set to "#'^2hg9a&nm38*us".
diff --git a/tests/lib/test_02_subscribe_qos0.py b/tests/lib/test_02_subscribe_qos0.py
index 27f91b5c..d1ff422e 100644
--- a/tests/lib/test_02_subscribe_qos0.py
+++ b/tests/lib/test_02_subscribe_qos0.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a correct SUBSCRIBE to a topic with QoS 0.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id subscribe-qos0-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a SUBSCRIBE
diff --git a/tests/lib/test_02_subscribe_qos1.py b/tests/lib/test_02_subscribe_qos1.py
index 8d7c8eae..1e96d491 100644
--- a/tests/lib/test_02_subscribe_qos1.py
+++ b/tests/lib/test_02_subscribe_qos1.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a correct SUBSCRIBE to a topic with QoS 1.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id subscribe-qos1-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a SUBSCRIBE
diff --git a/tests/lib/test_02_subscribe_qos2.py b/tests/lib/test_02_subscribe_qos2.py
index cb9308b2..5d04aff5 100644
--- a/tests/lib/test_02_subscribe_qos2.py
+++ b/tests/lib/test_02_subscribe_qos2.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a correct SUBSCRIBE to a topic with QoS 2.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id subscribe-qos2-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a SUBSCRIBE
diff --git a/tests/lib/test_03_publish_b2c_qos1.py b/tests/lib/test_03_publish_b2c_qos1.py
index 15e22eae..20cc1f6d 100644
--- a/tests/lib/test_03_publish_b2c_qos1.py
+++ b/tests/lib/test_03_publish_b2c_qos1.py
@@ -1,6 +1,6 @@
 # Test whether a client responds correctly to a PUBLISH with QoS 1.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id publish-qos1-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK the client should verify that rc==0.
diff --git a/tests/lib/test_03_publish_helper_qos0.py b/tests/lib/test_03_publish_helper_qos0.py
index 17a91764..1a2fac21 100644
--- a/tests/lib/test_03_publish_helper_qos0.py
+++ b/tests/lib/test_03_publish_helper_qos0.py
@@ -1,7 +1,7 @@
 # Test whether a client sends a correct PUBLISH to a topic with QoS 0.
 # Use paho.mqtt.publish helper for that.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id publish-helper-qos0-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a PUBLISH message
diff --git a/tests/lib/test_03_publish_helper_qos0_v5.py b/tests/lib/test_03_publish_helper_qos0_v5.py
index d889d739..23722917 100644
--- a/tests/lib/test_03_publish_helper_qos0_v5.py
+++ b/tests/lib/test_03_publish_helper_qos0_v5.py
@@ -1,7 +1,7 @@
 # Test whether a client sends a correct PUBLISH to a topic with QoS 0.
 # Use paho.mqtt.publish helper for that.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id publish-helper-qos0-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a PUBLISH message
diff --git a/tests/lib/test_03_publish_qos0.py b/tests/lib/test_03_publish_qos0.py
index 0bdcc1b0..018f39b9 100644
--- a/tests/lib/test_03_publish_qos0.py
+++ b/tests/lib/test_03_publish_qos0.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a correct PUBLISH to a topic with QoS 0.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id publish-qos0-test
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a PUBLISH message
diff --git a/tests/lib/test_03_publish_qos0_no_payload.py b/tests/lib/test_03_publish_qos0_no_payload.py
index 33b2c206..8cc39dbd 100644
--- a/tests/lib/test_03_publish_qos0_no_payload.py
+++ b/tests/lib/test_03_publish_qos0_no_payload.py
@@ -1,6 +1,6 @@
 # Test whether a client sends a correct PUBLISH to a topic with QoS 0 and no payload.
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id publish-qos0-test-np
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a PUBLISH message
diff --git a/tests/lib/test_08_ssl_connect_cert_auth.py b/tests/lib/test_08_ssl_connect_cert_auth.py
index 3c467746..24e00d99 100644
--- a/tests/lib/test_08_ssl_connect_cert_auth.py
+++ b/tests/lib/test_08_ssl_connect_cert_auth.py
@@ -5,7 +5,7 @@
 import tests.paho_test as paho_test
 from tests.paho_test import ssl
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id 08-ssl-connect-crt-auth
 # It should use the CA certificate ssl/all-ca.crt for verifying the server.
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
diff --git a/tests/lib/test_08_ssl_connect_cert_auth_pw.py b/tests/lib/test_08_ssl_connect_cert_auth_pw.py
index 315b30c6..435bd6a7 100644
--- a/tests/lib/test_08_ssl_connect_cert_auth_pw.py
+++ b/tests/lib/test_08_ssl_connect_cert_auth_pw.py
@@ -5,7 +5,7 @@
 import tests.paho_test as paho_test
 from tests.paho_test import ssl
 
-# The client should connect to port 1888 with keepalive=60, clean session set,
+# The client should connect with keepalive=60, clean session set,
 # and client id 08-ssl-connect-crt-auth
 # It should use the CA certificate ssl/all-ca.crt for verifying the server.
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
diff --git a/tests/lib/test_08_ssl_connect_no_auth.py b/tests/lib/test_08_ssl_connect_no_auth.py
index dc42e266..efe64e10 100644
--- a/tests/lib/test_08_ssl_connect_no_auth.py
+++ b/tests/lib/test_08_ssl_connect_no_auth.py
@@ -1,6 +1,6 @@
 # Test whether a client produces a correct connect and subsequent disconnect when using SSL.
 #
-# The client should connect to port 1888 with keepalive=60, clean session set,# and client id 08-ssl-connect-no-auth
+# The client should connect with keepalive=60, clean session set,# and client id 08-ssl-connect-no-auth
 # It should use the CA certificate ssl/all-ca.crt for verifying the server.
 # The test will send a CONNACK message to the client with rc=0. Upon receiving
 # the CONNACK and verifying that rc=0, the client should send a DISCONNECT
diff --git a/tests/paho_test.py b/tests/paho_test.py
index d9bf3b7c..a0f9a886 100644
--- a/tests/paho_test.py
+++ b/tests/paho_test.py
@@ -3,7 +3,6 @@
 import os
 import socket
 import struct
-import sys
 import time
 
 from tests.consts import ssl_path
@@ -26,13 +25,25 @@ def __init__(self, message="Mismatched packets"):
         self.message = message
 
 
+def bind_to_any_free_port(sock) -> int:
+    """
+    Bind a socket to an available port on localhost,
+    and return the port number.
+    """
+    while True:
+        try:
+            sock.bind(('', 0))
+            return sock.getsockname()[1]
+        except OSError:
+            pass
+
+
 def create_server_socket():
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
     sock.settimeout(10)
-    sock.bind(('', 1888))
+    port = bind_to_any_free_port(sock)
     sock.listen(5)
-    return sock
+    return (sock, port)
 
 
 def create_server_socket_ssl(cert_reqs=None):
@@ -57,9 +68,9 @@ def create_server_socket_ssl(cert_reqs=None):
         context.verify_mode = cert_reqs
     ssock = context.wrap_socket(sock, server_side=True)
     ssock.settimeout(10)
-    ssock.bind(('', 1888))
+    port = bind_to_any_free_port(ssock)
     ssock.listen(5)
-    return ssock
+    return (ssock, port)
 
 
 def expect_packet(sock, name, expected):
@@ -701,29 +712,6 @@ def pack_remaining_length(remaining_length):
             return s
 
 
-def get_port(count=1):
-    if count == 1:
-        if len(sys.argv) == 2:
-            return int(sys.argv[1])
-        else:
-            return 1888
-    else:
-        if len(sys.argv) == 1+count:
-            p = ()
-            for i in range(0, count):
-                p = p + (int(sys.argv[1+i]),)
-            return p
-        else:
-            return tuple(range(1888, 1888+count))
-
-
-def get_lib_port():
-    if len(sys.argv) == 3:
-        return int(sys.argv[2])
-    else:
-        return 1888
-
-
 def do_ping(sock, error_string="pingresp"):
      do_send_receive(sock, gen_pingreq(), gen_pingresp(), error_string)
 
@@ -773,3 +761,10 @@ def wait_for_keyboard_interrupt():
             time.sleep(0.1)
     except KeyboardInterrupt:
         pass
+
+
+def get_test_server_port() -> int:
+    """
+    Get the port number for the test server.
+    """
+    return int(os.environ['PAHO_SERVER_PORT'])
diff --git a/tests/test_client.py b/tests/test_client.py
index 59fdda60..2f1b45b5 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -29,7 +29,7 @@ def on_connect(mqttc, obj, flags, rc):
 
         mqttc.on_connect = on_connect
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
@@ -67,7 +67,7 @@ def on_connect(mqttc, obj, flags, rc):
 
         mqttc.on_connect = on_connect
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
@@ -104,7 +104,7 @@ def on_message(client, userdata, msg):
 
         mqttc.on_message = on_message
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
@@ -148,7 +148,7 @@ def on_message(client, userdata, msg):
 
         mqttc.on_message = on_message
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
@@ -188,7 +188,7 @@ def test_valid_utf8_topic_publish(self, fake_broker):
         # It should be non-ascii multi-bytes character
         topic = unicodedata.lookup('SNOWMAN')
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
@@ -253,7 +253,7 @@ def callback2(client, userdata, msg):
         mqttc.message_callback_add('topic/callback/1', callback1)
         mqttc.message_callback_add('topic/callback/+', callback2)
 
-        mqttc.connect_async("localhost", 1888)
+        mqttc.connect_async("localhost", fake_broker.port)
         mqttc.loop_start()
 
         try:
diff --git a/tests/test_websocket_integration.py b/tests/test_websocket_integration.py
index b8a28309..6a54c0b2 100644
--- a/tests/test_websocket_integration.py
+++ b/tests/test_websocket_integration.py
@@ -60,7 +60,7 @@ def handle(_self):
 
         with fake_websocket_broker.serve(WebsocketHandler):
             with pytest.raises(WebsocketConnectionError) as exc:
-                mqttc.connect("localhost", 1888, keepalive=10)
+                mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
         assert str(exc.value) == "WebSocket handshake error"
 
@@ -103,7 +103,7 @@ def test_no_upgrade(self, proto_ver, proto_name, fake_websocket_broker,
 
         with fake_websocket_broker.serve(response):
             with pytest.raises(WebsocketConnectionError) as exc:
-                mqttc.connect("localhost", 1888, keepalive=10)
+                mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
         assert str(exc.value) == "WebSocket handshake error, connection not upgraded"
 
@@ -121,7 +121,7 @@ def test_bad_secret_key(self, proto_ver, proto_name, fake_websocket_broker,
 
         with fake_websocket_broker.serve(response):
             with pytest.raises(WebsocketConnectionError) as exc:
-                mqttc.connect("localhost", 1888, keepalive=10)
+                mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
         assert str(exc.value) == "WebSocket handshake error, invalid secret key"
 
@@ -179,7 +179,7 @@ def test_successful_connection(self, proto_ver, proto_name,
         response = self._get_callback_handler(init_response_headers)
 
         with fake_websocket_broker.serve(response):
-            mqttc.connect("localhost", 1888, keepalive=10)
+            mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
             mqttc.disconnect()
 
@@ -213,7 +213,7 @@ def check_path_correct(decoded):
         )
 
         with fake_websocket_broker.serve(response):
-            mqttc.connect("localhost", 1888, keepalive=10)
+            mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
             mqttc.disconnect()
 
@@ -249,6 +249,6 @@ def check_headers_used(decoded):
         )
 
         with fake_websocket_broker.serve(response):
-            mqttc.connect("localhost", 1888, keepalive=10)
+            mqttc.connect("localhost", fake_websocket_broker.port, keepalive=10)
 
             mqttc.disconnect()
diff --git a/tests/testsupport/broker.py b/tests/testsupport/broker.py
index b901a6df..85a283a8 100644
--- a/tests/testsupport/broker.py
+++ b/tests/testsupport/broker.py
@@ -13,7 +13,8 @@ def __init__(self):
         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         sock.settimeout(30)
-        sock.bind(("localhost", 1888))
+        sock.bind(("localhost", 0))
+        self.port = sock.getsockname()[1]
         sock.listen(1)
 
         self._sock = sock
@@ -71,7 +72,7 @@ def __init__(self):
         super(FakeWebsocketBroker, self).__init__()
 
         self.host = "localhost"
-        self.port = 1888
+        self.port = -1  # Will be set by `serve()`
 
         self._server = None
         self._running = True
@@ -79,10 +80,11 @@ def __init__(self):
 
     @contextlib.contextmanager
     def serve(self, tcphandler):
-        self._server = ThreadedTCPServer((self.host, self.port), tcphandler)
+        self._server = ThreadedTCPServer((self.host, 0), tcphandler)
 
         try:
             self.start()
+            self.port = self._server.server_address[1]
 
             if not self._running:
                 raise RuntimeError("Error starting server")
@@ -99,8 +101,6 @@ def run(self):
 
 @pytest.fixture
 def fake_websocket_broker():
-    socketserver.TCPServer.allow_reuse_address = True
-
     broker = FakeWebsocketBroker()
 
     yield broker