diff --git a/.stestr.conf b/.stestr.conf
index 5fcccac..e4750de 100644
--- a/.stestr.conf
+++ b/.stestr.conf
@@ -1,3 +1,3 @@
 [DEFAULT]
-test_path=./unit_tests
-top_dir=./
+test_path=./tests/unit
+top_dir=./tests
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c700c32..d931f11 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -35,9 +35,9 @@ TODO
 ## Testing
 
 The Python operator framework includes a very nice harness for testing
-operator behaviour without full deployment. Just `run_tests`:
+operator behaviour without full deployment. Run tests using command:
 
-    ./run_tests
+    tox -e py3
 
 ## Deployment
 
diff --git a/requirements.txt b/requirements.txt
index 592fb03..f1f8957 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,14 +1,31 @@
-ops
-jinja2
-# Get resources from github until cacerts issue is charmbuild image is fixed.
-# git+https://opendev.org/openstack/charm-ops-openstack#egg=ops_openstack
-# git+https://opendev.org/openstack/charm-ops-interface-tls-certificates#egg=interface_tls_certificates
-git+https://github.com/openstack/charm-ops-interface-tls-certificates#egg=interface_tls_certificates
+# This file is managed centrally by release-tools and should not be modified
+# within individual charm repos.  See the 'global' dir contents for available
+# choices of *requirements.txt files for OpenStack Charms:
+#     https://github.com/openstack-charmers/release-tools
+#
 
-git+https://github.com/openstack-charmers/advanced-sunbeam-openstack#egg=ops_sunbeam
+# NOTE: newer versions of cryptography require a Rust compiler to build,
+# see
+# * https://github.com/openstack-charmers/zaza/issues/421
+# * https://mail.python.org/pipermail/cryptography-dev/2021-January/001003.html
+#
+cryptography<3.4
+jinja2
 lightkube
 lightkube-models
-cryptography < 3.4
+ops
+git+https://github.com/openstack-charmers/advanced-sunbeam-openstack#egg=ops_sunbeam
+
+python-keystoneclient  # keystone-k8s
+
+# Used for Traefik
+# Note: Remove when traefik-k8s-operator v1 library is released
+serialized_data_interface
+
+# Get resources from github until cacerts issue is charmbuild image is fixed.
+git+https://github.com/openstack/charm-ops-interface-tls-certificates#egg=interface_tls_certificates
+
+# Note: Required for cinder-k8s, cinder-ceph-k8s, glance-k8s, nova-k8s
 git+https://github.com/openstack/charm-ops-interface-ceph-client#egg=interface_ceph_client
 # Charmhelpers is only present as interface_ceph_client uses it.
 git+https://github.com/juju/charm-helpers.git#egg=charmhelpers
diff --git a/run_tests b/run_tests
deleted file mode 100755
index 985f747..0000000
--- a/run_tests
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh -e
-# Copyright 2021 Canonical Ltd.
-# See LICENSE file for licensing details.
-
-if [ -z "$VIRTUAL_ENV" -a -d venv/ ]; then
-    . venv/bin/activate
-fi
-
-if [ -z "$PYTHONPATH" ]; then
-    export PYTHONPATH="lib:src"
-else
-    export PYTHONPATH="lib:src:$PYTHONPATH"
-fi
-
-flake8
-coverage run --branch --source=src -m unittest -v "$@"
-coverage report -m
diff --git a/src/charm.py b/src/charm.py
index 8350f0e..026e30f 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -367,6 +367,7 @@ class OVNCentralXenaOperatorCharm(OVNCentralOperatorCharm):
 
     openstack_release = 'xena'
 
+
 if __name__ == "__main__":
     # Note: use_juju_for_storage=True required per
     # https://github.com/canonical/operator/issues/506
diff --git a/test-requirements.txt b/test-requirements.txt
index 8057d2c..35f58ad 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,17 +1,10 @@
-# This file is managed centrally.  If you find the need to modify this as a
-# one-off, please don't.  Intead, consult #openstack-charms and ask about
-# requirements management in charms via bot-control.  Thank you.
-charm-tools>=2.4.4
-coverage>=3.6
-mock>=1.2
-flake8>=2.2.4,<=2.4.1
-pyflakes==2.1.1
-stestr>=2.2.0
-requests>=2.18.4
-psutil
-# oslo.i18n dropped py35 support
-oslo.i18n<4.0.0
-git+https://github.com/openstack-charmers/zaza.git#egg=zaza
-git+https://github.com/openstack-charmers/zaza-openstack-tests.git#egg=zaza.openstack
-pytz    # workaround for 14.04 pip/tox
-pyudev  # for ceph-* charm unit tests (not mocked?)
+# This file is managed centrally by release-tools and should not be modified
+# within individual charm repos.  See the 'global' dir contents for available
+# choices of *requirements.txt files for OpenStack Charms:
+#     https://github.com/openstack-charmers/release-tools
+#
+
+coverage
+mock
+flake8
+stestr
diff --git a/unit_tests/__init__.py b/tests/unit/__init__.py
similarity index 100%
rename from unit_tests/__init__.py
rename to tests/unit/__init__.py
diff --git a/unit_tests/test_ovn_central_charm.py b/tests/unit/test_ovn_central_charm.py
similarity index 98%
rename from unit_tests/test_ovn_central_charm.py
rename to tests/unit/test_ovn_central_charm.py
index b691cdc..afdb06c2 100644
--- a/unit_tests/test_ovn_central_charm.py
+++ b/tests/unit/test_ovn_central_charm.py
@@ -15,10 +15,6 @@
 # limitations under the License.
 
 import mock
-import sys
-
-sys.path.append('lib')  # noqa
-sys.path.append('src')  # noqa
 
 import charm
 import ops_sunbeam.test_utils as test_utils
diff --git a/tox.ini b/tox.ini
index 5741249..7044cca 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,73 +1,76 @@
-# Operator charm (with zaza): tox.ini
+# Source charm: ./tox.ini
+# This file is managed centrally by release-tools and should not be modified
+# within individual charm repos.  See the 'global' dir contents for available
+# choices of tox.ini for OpenStack Charms:
+#     https://github.com/openstack-charmers/release-tools
 
 [tox]
-envlist = pep8,py3
 skipsdist = True
-# NOTE: Avoid build/test env pollution by not enabling sitepackages.
+envlist = pep8,py3
 sitepackages = False
-# NOTE: Avoid false positives by not skipping missing interpreters.
 skip_missing_interpreters = False
-# NOTES:
-# * We avoid the new dependency resolver by pinning pip < 20.3, see
-#   https://github.com/pypa/pip/issues/9187
-# * Pinning dependencies requires tox >= 3.2.0, see
-#   https://tox.readthedocs.io/en/latest/config.html#conf-requires
-# * It is also necessary to pin virtualenv as a newer virtualenv would still
-#   lead to fetching the latest pip in the func* tox targets, see
-#   https://stackoverflow.com/a/38133283
-requires = pip < 20.3
-           virtualenv < 20.0
-# NOTE: https://wiki.canonical.com/engineering/OpenStack/InstallLatestToxOnOsci
 minversion = 3.18.0
 
+[vars]
+src_path = {toxinidir}/src/
+tst_path = {toxinidir}/tests/
+lib_path = {toxinidir}/lib/
+
 [testenv]
-setenv = VIRTUAL_ENV={envdir}
-         PYTHONHASHSEED=0
-         CHARM_DIR={envdir}
+basepython = python3
+setenv =
+  PYTHONPATH = {toxinidir}:{[vars]lib_path}:{[vars]src_path}
+passenv =
+  PYTHONPATH
 install_command =
   pip install {opts} {packages}
 commands = stestr run --slowest {posargs}
-whitelist_externals =
-    git
-    add-to-archive.py
-    bash
-    charmcraft
-passenv = HOME TERM CS_* OS_* TEST_*
-deps = -r{toxinidir}/test-requirements.txt
+allowlist_externals =
+  git
+  charmcraft
+  fetch-libs.sh
+deps =
+  -r{toxinidir}/test-requirements.txt
+
+[testenv:build]
+basepython = python3
+deps =
+commands =
+  charmcraft clean
+  charmcraft -v pack
 
 [testenv:fetch]
 basepython = python3
 deps =
 commands =
-  ./fetch-libs.sh
-
-[testenv:py3.8]
-basepython = python3.8
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
-
-[testenv:py3.9]
-basepython = python3.9
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+  {toxinidir}/fetch-libs.sh
 
 [testenv:py3]
 basepython = python3
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+deps =
+  {[testenv]deps}
+  -r{toxinidir}/requirements.txt
+
+[testenv:py3.8]
+basepython = python3.8
+deps = {[testenv:py3]deps}
+
+[testenv:py3.9]
+basepython = python3.9
+deps = {[testenv:py3]deps}
+
+[testenv:py3.10]
+basepython = python3.10
+deps = {[testenv:py3]deps}
 
 [testenv:pep8]
 basepython = python3
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
-commands = flake8 {posargs} src unit_tests tests
+deps = {[testenv]deps}
+commands = flake8 {posargs} {[vars]src_path} {[vars]tst_path}
 
 [testenv:cover]
-# Technique based heavily upon
-# https://github.com/openstack/nova/blob/master/tox.ini
 basepython = python3
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+deps = {[testenv:py3]deps}
 setenv =
     {[testenv]setenv}
     PYTHON=coverage run
@@ -87,45 +90,8 @@ source =
     .
 omit =
     .tox/*
-    */charmhelpers/*
-    unit_tests/*
+    tests/*
     src/templates/*
 
-[testenv:venv]
-basepython = python3
-commands = {posargs}
-
-[testenv:build]
-basepython = python3
-deps = -r{toxinidir}/build-requirements.txt
-commands =
-    charmcraft build
-
-[testenv:func-noop]
-basepython = python3
-commands =
-    functest-run-suite --help
-
-[testenv:func]
-basepython = python3
-commands =
-    functest-run-suite --keep-model
-
-[testenv:func-smoke]
-basepython = python3
-commands =
-    functest-run-suite --keep-model --smoke
-
-[testenv:func-dev]
-basepython = python3
-commands =
-    functest-run-suite --keep-model --dev
-
-[testenv:func-target]
-basepython = python3
-commands =
-    functest-run-suite --keep-model --bundle {posargs}
-
 [flake8]
-# Ignore E902 because the unit_tests directory is missing in the built charm.
-ignore = E402,E226,E902
+ignore=E226,W504