diff --git a/.stestr.conf b/.stestr.conf
index 7e7d325..ec410bf 100644
--- a/.stestr.conf
+++ b/.stestr.conf
@@ -1,4 +1,4 @@
 [DEFAULT]
-test_path=./os_refresh_config/tests
+test_path=${OS_TEST_PATH:-./os_refresh_config/tests/unit}
 top_dir=./
 
diff --git a/os_refresh_config/os_refresh_config.py b/os_refresh_config/os_refresh_config.py
old mode 100755
new mode 100644
index 260e086..9aabea5
--- a/os_refresh_config/os_refresh_config.py
+++ b/os_refresh_config/os_refresh_config.py
@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 # Copyright 2013 Hewlett-Packard Development Company, L.P.
 # All Rights Reserved.
 #
@@ -159,7 +158,3 @@ def main(argv=sys.argv):
             log.debug('No dir for phase %s' % phase)
 
     return exit(lock)
-
-
-if __name__ == '__main__':
-    sys.exit(main(sys.argv))
diff --git a/os_refresh_config/tests/functional/__init__.py b/os_refresh_config/tests/functional/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/os_refresh_config/tests/test_cmd.py b/os_refresh_config/tests/functional/test_cmd.py
similarity index 96%
rename from os_refresh_config/tests/test_cmd.py
rename to os_refresh_config/tests/functional/test_cmd.py
index 49038a8..a409130 100644
--- a/os_refresh_config/tests/test_cmd.py
+++ b/os_refresh_config/tests/functional/test_cmd.py
@@ -17,16 +17,11 @@ import time
 import fixtures
 import testtools
 
-script_path = os.path.join(
-    os.path.dirname(os.path.realpath(__file__)),
-    '../os_refresh_config.py')
-
 
 class TestCmd(testtools.TestCase):
 
     def setUp(self):
         super(TestCmd, self).setUp()
-        self.assertTrue(os.path.exists(script_path))
         self.useFixture(fixtures.NestedTempfile())
         self.base_dir = self.useFixture(fixtures.TempDir())
         self.lockdir = self.useFixture(fixtures.TempDir())
@@ -49,8 +44,7 @@ class TestCmd(testtools.TestCase):
             'PATH': os.environ.get('PATH')
         }
         cmd_args = [
-            script_path,
-            '--lockfile', self.lockfile
+            'os-refresh-config', '--lockfile', self.lockfile
         ]
         if args:
             cmd_args.extend(args)
diff --git a/os_refresh_config/tests/unit/__init__.py b/os_refresh_config/tests/unit/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/os_refresh_config/tests/test_main.py b/os_refresh_config/tests/unit/test_main.py
similarity index 100%
rename from os_refresh_config/tests/test_main.py
rename to os_refresh_config/tests/unit/test_main.py
diff --git a/os_refresh_config/tests/test_os_refresh_config.py b/os_refresh_config/tests/unit/test_os_refresh_config.py
similarity index 100%
rename from os_refresh_config/tests/test_os_refresh_config.py
rename to os_refresh_config/tests/unit/test_os_refresh_config.py
diff --git a/requirements.txt b/requirements.txt
index f749343..415555e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,2 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
-dib-utils>=0.0.8 # Apache-2.0
 psutil>=3.2.2 # BSD
diff --git a/setup.cfg b/setup.cfg
index 19551a5..6e8c87c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,6 +27,8 @@ classifier =
 [files]
 packages =
 	os_refresh_config
+scripts =
+    tools/dib-run-parts
 
 [entry_points]
 console_scripts =
diff --git a/tools/dib-run-parts b/tools/dib-run-parts
new file mode 100755
index 0000000..0f81be1
--- /dev/null
+++ b/tools/dib-run-parts
@@ -0,0 +1,144 @@
+#!/bin/bash
+# Inspired by Debian and RedHat run-parts but portable and specific to di-b.
+#
+# Copyright 2012 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+allowed_regex=${RUN_PARTS_REGEX:-"^[0-9A-Za-z_-]+$"}
+show_list=
+
+set -ue
+set -o pipefail
+
+name=$(basename $0)
+
+usage() {
+    echo "Usage: $name [OPTION] scripts_directory"
+    echo "Option:"
+    echo "      --list  print names of all valid files"
+    echo
+    echo "Examples:"
+    echo "      dib-run-parts --list /opt/stack/os-config-refresh/configure.d/"
+    echo "      dib-run-parts /opt/stack/os-config-refresh/configure.d/"
+    exit 1
+} >&2
+
+
+output_prefix() {
+    printf "%s %s " "${name}" "$(date)" >&2
+}
+
+output () {
+    output_prefix
+    echo $* >&2
+}
+
+output_printf () {
+    local FORMAT="$1"
+    shift
+    output_prefix
+    printf "${FORMAT}" $@ >&2
+}
+
+# source the environment files from environment.d
+#  arg : target_dir
+source_environment() {
+
+    local dir=$target_dir/../environment.d
+    local env_files
+    local xtrace
+
+    if [ -d ${dir} ] ; then
+        env_files=$(find ${dir} -maxdepth 1 -xtype f | \
+                           grep -E "/[0-9A-Za-z_\.-]+$" | \
+                           LANG=C sort -n)
+        for env_file in $env_files ; do
+            output "Sourcing environment file ${env_file}"
+            # Set tracing as we import these environment files; it's
+            # nice to see the definitions in the logs
+            xtrace=$(set +o | grep xtrace)
+            set -o xtrace
+            source $env_file
+            $xtrace
+        done
+    fi
+}
+
+if [ $# -lt 1 ] ; then
+    usage
+fi
+
+if [ "$1" == "--list" ] ; then
+    show_list="1"
+    shift
+fi
+
+target_dir="${1:-}"
+
+if ! [ -d "$target_dir" ] ; then
+    output "Scripts directory [$target_dir] must exist and be a directory"
+    usage
+fi
+
+# We specifically only want to sort *by the numbers*.
+# Lexical sorting is not guaranteed, and identical numbers may be
+# parallelized later
+# Note: -maxdepth 1 ensures only files in the target directory (but not
+# subdirectories) are run, which is the way run-parts behaves.
+targets=$(find $target_dir -maxdepth 1 -xtype f -executable -printf '%f\n' | grep -E "$allowed_regex" | LANG=C sort -n || echo "")
+
+if [ "$show_list" == "1" ] ; then
+    for target in $targets ; do
+        echo "${target_dir}/${target}"
+    done
+    exit 0
+fi
+
+PROFILE_DIR=$(mktemp -d --tmpdir profiledir.XXXXXX)
+
+# note, run this in a sub-shell so we don't pollute our
+# own environment with source_environment
+(
+    source_environment
+
+    for target in $targets ; do
+        output "Running $target_dir/$target"
+        target_tag=${target//\//_}
+        date +%s.%N > $PROFILE_DIR/start_$target_tag
+        $target_dir/$target
+        target_tag=${target//\//_}
+        date +%s.%N > $PROFILE_DIR/stop_$target_tag
+        output "$target completed"
+    done
+)
+
+output "----------------------- PROFILING -----------------------"
+output ""
+output "Target: $(basename $target_dir)"
+output ""
+output_printf "%-40s %9s\n" Script Seconds
+output_printf "%-40s %9s\n" --------------------------------------- ----------
+output ""
+pushd $PROFILE_DIR > /dev/null
+for target in $(find . -name 'start_*' -printf '%f\n' | env LC_ALL=C sort -n) ; do
+    stop_file=stop_${target##start_}
+    start_seconds=$(cat $target)
+    stop_seconds=$(cat $stop_file)
+    duration=$(echo - | awk "{ print $stop_seconds - $start_seconds }")
+    LC_NUMERIC=C LC_ALL=C output_printf "%-40s %10.3f\n" ${target##start_} $duration
+done
+popd > /dev/null
+rm -rf $PROFILE_DIR
+output ""
+output "--------------------- END PROFILING ---------------------"
diff --git a/tools/tests/run_tests.sh b/tools/tests/run_tests.sh
new file mode 100755
index 0000000..24f9146
--- /dev/null
+++ b/tools/tests/run_tests.sh
@@ -0,0 +1,16 @@
+#!/bin/bash
+#
+# Runs all test cases in this directory
+#
+
+set -ue
+set -o pipefail
+
+TESTS_BASE_DIR=$(cd $(dirname "$0") && pwd)
+
+for tc in ${TESTS_BASE_DIR}/tc??.sh; do
+    echo "--- Running ${tc} ---"
+    ${tc}
+done
+
+echo "--- TESTS COMPLETE ---"
diff --git a/tools/tests/tc01.sh b/tools/tests/tc01.sh
new file mode 100755
index 0000000..c040d52
--- /dev/null
+++ b/tools/tests/tc01.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+#
+# Runs dib-run-parts on an empty directory.
+#
+
+set -ue
+set -o pipefail
+set -x
+
+TESTS_BASE_DIR=$(cd $(dirname "$0") && pwd)
+
+DRP_BIN=${TESTS_BASE_DIR}/../dib-run-parts
+
+TEST_EXEC_DIR=${TESTS_BASE_DIR}/tc01/td
+
+mkdir -p ${TEST_EXEC_DIR}
+rval=0
+
+RES=$(${DRP_BIN} --list ${TEST_EXEC_DIR})
+if test $? -ne 0; then
+    echo "*** FAILED: --list of empty dir failed"
+    rval=1
+fi
+if test -n "${RES}"; then
+    echo "*** FAILED: --list of empty dir not empty"
+    rval=1
+fi
+
+RES=$(${DRP_BIN} ${TEST_EXEC_DIR} 2>/dev/null)
+if test $? -ne 0; then
+    echo "*** FAILED: dib-run-parts on empty dir failed"
+    rval=1
+fi
+if test -n "${RES}"; then
+    echo "*** FAILED: dib-run-parts on empty dir not empty"
+    rval=1
+fi
+
+exit ${rval}
diff --git a/tools/tests/tc02.sh b/tools/tests/tc02.sh
new file mode 100755
index 0000000..795af8a
--- /dev/null
+++ b/tools/tests/tc02.sh
@@ -0,0 +1,46 @@
+#!/bin/bash
+#
+# Runs dib-run-parts on directory containing some scripts.
+#
+
+set -ue
+set -o pipefail
+set -x
+
+TESTS_BASE_DIR=$(cd $(dirname "$0") && pwd)
+
+DRP_BIN=${TESTS_BASE_DIR}/../dib-run-parts
+
+TEST_EXEC_DIR=${TESTS_BASE_DIR}/tc02/td
+
+rval=0
+
+RES=$(${DRP_BIN} --list ${TEST_EXEC_DIR})
+if test $? -ne 0; then
+    echo "*** FAILED: --list failed"
+    rval=1
+fi
+
+EXPECTED="${TESTS_BASE_DIR}/tc02/td/call_me_1
+${TESTS_BASE_DIR}/tc02/td/call_me_2"
+
+if test "${EXPECTED}" != "${RES}"; then
+    echo "*** FAILED: --list returns incorrect result"
+    rval=1
+fi
+
+RES=$(${DRP_BIN} ${TEST_EXEC_DIR} 2>/dev/null)
+if test $? -ne 0; then
+    echo "*** FAILED: dib-run-parts on empty dir failed"
+    rval=1
+fi
+
+EXPECTED="call_me_1 called
+call_me_2 called"
+
+if test "${EXPECTED}" != "${RES}"; then
+    echo "*** FAILED: dib-run-parts returns incorrect result"
+    rval=1
+fi
+
+exit ${rval}
diff --git a/tools/tests/tc02/td/call_me_1 b/tools/tests/tc02/td/call_me_1
new file mode 100755
index 0000000..4e3b6a0
--- /dev/null
+++ b/tools/tests/tc02/td/call_me_1
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo "call_me_1 called"
diff --git a/tools/tests/tc02/td/call_me_2 b/tools/tests/tc02/td/call_me_2
new file mode 100755
index 0000000..d96423d
--- /dev/null
+++ b/tools/tests/tc02/td/call_me_2
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo "call_me_2 called"
diff --git a/tools/tests/tc03.sh b/tools/tests/tc03.sh
new file mode 100755
index 0000000..996fe9f
--- /dev/null
+++ b/tools/tests/tc03.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+#
+# Runs dib-run-parts on directory containing some scripts
+# and using the environment directory.
+#
+
+set -ue
+set -o pipefail
+set -x
+
+TESTS_BASE_DIR=$(dirname $0)
+
+DRP_BIN=${TESTS_BASE_DIR}/../dib-run-parts
+
+TEST_EXEC_DIR=${TESTS_BASE_DIR}/tc03/td
+
+rval=0
+
+RES=$(${DRP_BIN} ${TEST_EXEC_DIR} 2>/dev/null)
+if test $? -ne 0; then
+    echo "*** FAILED: dib-run-parts failed"
+    rval=1
+fi
+
+EXPECTED="call_me_1 called [Some thing]
+call_me_2 called [Other thing]"
+
+if test "${EXPECTED}" != "${RES}"; then
+    echo "*** FAILED: dib-run-parts returns incorrect result"
+    rval=1
+fi
+
+exit ${rval}
diff --git a/tools/tests/tc03/environment.d/set_var.bash b/tools/tests/tc03/environment.d/set_var.bash
new file mode 100644
index 0000000..d9dc4ac
--- /dev/null
+++ b/tools/tests/tc03/environment.d/set_var.bash
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+export CM1="Some thing"
+export CM2="Other thing"
+
diff --git a/tools/tests/tc03/td/call_me_1 b/tools/tests/tc03/td/call_me_1
new file mode 100755
index 0000000..11a4850
--- /dev/null
+++ b/tools/tests/tc03/td/call_me_1
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo "call_me_1 called [${CM1}]"
diff --git a/tools/tests/tc03/td/call_me_2 b/tools/tests/tc03/td/call_me_2
new file mode 100755
index 0000000..db5dec8
--- /dev/null
+++ b/tools/tests/tc03/td/call_me_2
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo "call_me_2 called [${CM2}]"
diff --git a/tox.ini b/tox.ini
index 461d023..9e6d358 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 minversion = 3.1.0
-skipsdist = True
 envlist = py3,pep8
+skipsdist = false
 skip_missing_interpreters = true
 # this allows tox to infer the base python from the environment name
 # and override any basepython configured in this file
@@ -9,7 +9,6 @@ ignore_basepython_conflict=true
 
 [testenv]
 basepython = python3
-usedevelop = True
 deps =
        -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
        -r{toxinidir}/requirements.txt
@@ -35,6 +34,15 @@ commands =
 [testenv:venv]
 commands = {posargs}
 
+[testenv:functional]
+setenv =
+  OS_TEST_PATH=os_refresh_config/tests/functional
+commands =
+  stestr run --slowest {posargs}
+  {toxinidir}/tools/tests/run_tests.sh {posargs}
+allowlist_externals =
+  {toxinidir}/tools/tests/run_tests.sh
+
 [flake8]
 ignore = E125
 exclude = .venv,.tox,dist,doc,*.egg
diff --git a/zuul.d/layout.yaml b/zuul.d/layout.yaml
index 7d1cedf..0ee2dd8 100644
--- a/zuul.d/layout.yaml
+++ b/zuul.d/layout.yaml
@@ -3,3 +3,9 @@
       - check-requirements
       - openstack-cover-jobs
       - openstack-python3-jobs
+    check:
+      jobs:
+        - openstack-tox-functional
+    gate:
+      jobs:
+        - openstack-tox-functional