diff --git a/oslo_metrics/__main__.py b/oslo_metrics/__main__.py
index d35a7680e2725b37f0f8ac85deadfe7443dbc633..c89347f3959326ee69514593b04994d35e592846 100644
--- a/oslo_metrics/__main__.py
+++ b/oslo_metrics/__main__.py
@@ -17,7 +17,6 @@ import os
 import select
 import signal
 import socket
-import stat
 import sys
 import threading
 from wsgiref.simple_server import make_server
@@ -33,7 +32,9 @@ oslo_metrics_configs = [
     cfg.StrOpt('metrics_socket_file',
                default='/var/tmp/metrics_collector.sock',
                help='Unix domain socket file to be used'
-                    'to send rpc related metrics'),
+                    ' to send rpc related metrics'),
+    cfg.IntOpt('prometheus_port', default=3000,
+               help='Port number to expose metrics in prometheus format.'),
 ]
 cfg.CONF.register_opts(oslo_metrics_configs, group='oslo_metrics')
 
@@ -97,7 +98,7 @@ def main():
     socket_path = cfg.CONF.oslo_metrics.metrics_socket_file
     m = MetricsListener(socket_path)
     try:
-        os.chmod(socket_path, stat.S_IRWXU | stat.S_IRWXO)
+        os.chmod(socket_path, 0o660)
     except OSError:
         LOG.error("Changing the mode of the file failed.... continuing")
     mt = threading.Thread(target=m.serve)
@@ -107,7 +108,7 @@ def main():
     app = make_wsgi_app()
     try:
         global httpd
-        httpd = make_server('', 3000, app)
+        httpd = make_server('', CONF.oslo_metrics.prometheus_port, app)
         signal.signal(signal.SIGTERM, handle_sigterm)
         httpd.serve_forever()
     except KeyboardInterrupt:
diff --git a/releasenotes/notes/port-config-ac5d9ee247a8ff9b.yaml b/releasenotes/notes/port-config-ac5d9ee247a8ff9b.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..346148d4365df64aa5340af2397cbb125f6f3ca8
--- /dev/null
+++ b/releasenotes/notes/port-config-ac5d9ee247a8ff9b.yaml
@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Port number to expose metrics in Prometheus format is now configurable.
diff --git a/releasenotes/source/index.rst b/releasenotes/source/index.rst
index 53e10e7e5832b6c6c6fa5e6bdb04ba11386db653..ff3337e10014bb6daa213a51a4f8357501bd8cc9 100644
--- a/releasenotes/source/index.rst
+++ b/releasenotes/source/index.rst
@@ -6,4 +6,5 @@ oslo.metrics Release Notes
    :maxdepth: 1
 
    unreleased
+   xena
    wallaby
diff --git a/releasenotes/source/xena.rst b/releasenotes/source/xena.rst
new file mode 100644
index 0000000000000000000000000000000000000000..1be85be3ebf18741d311aa41096d417a99c970bf
--- /dev/null
+++ b/releasenotes/source/xena.rst
@@ -0,0 +1,6 @@
+=========================
+Xena Series Release Notes
+=========================
+
+.. release-notes::
+   :branch: stable/xena
diff --git a/setup.cfg b/setup.cfg
index f333e0900026ddc025bcafe10375e110d6bf6e69..9a8db0d483e65a8d97bc2e2970c275f05f278e8f 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,12 +1,12 @@
 [metadata]
 name = oslo.metrics
 author = OpenStack
-author-email = openstack-discuss@lists.openstack.org
+author_email = openstack-discuss@lists.openstack.org
 summary = Oslo Metrics API
-description-file =
+description_file =
     README.rst
-home-page = https://opendev.org/openstack/oslo.metrics
-python-requires = >=3.6
+home_page = https://opendev.org/openstack/oslo.metrics
+python_requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Developers
diff --git a/tox.ini b/tox.ini
index b6c5d2061662ff8d65f6fa0ce70aa19f7612dd83..5df9975198e6b7d9676616489912bfe82f869702 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,11 +1,11 @@
 [tox]
-minversion = 3.2.0
+minversion = 3.18.0
 envlist = py3,pep8
 ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
-whitelist_externals =
+allowlist_externals =
   find
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
@@ -24,7 +24,7 @@ commands =
 commands = {posargs}
 
 [testenv:docs]
-whitelist_externals = rm
+allowlist_externals = rm
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
@@ -51,7 +51,7 @@ exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 import_exceptions =
 
 [testenv:releasenotes]
-whitelist_externals =
+allowlist_externals =
   rm
 deps = {[testenv:docs]deps}
 commands =