diff --git a/Dockerfile b/Dockerfile
index 1571e8b..9b7dcd9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -46,11 +46,17 @@ RUN INSTALL_PKGS="python3 python3-devel python3-setuptools python3-pip nss_wrapp
     dnf -y clean all --enablerepo='*'
 
 # Copy the S2I scripts from the specific language image to $STI_SCRIPTS_PATH.
-COPY ./s2i/bin/ $STI_SCRIPTS_PATH
+COPY 3.9/s2i/bin/ $STI_SCRIPTS_PATH
 
 # Copy extra files to the image.
-COPY ./root/ /
+COPY 3.9/root/ /
 
+# Python 3 only
+# Yes, the directory below is already copied by the previous command.
+# The problem here is that the wheels directory is copied as a symlink.
+# Only if you specify symlink directly as a source, COPY copies all the
+# files from the symlink destination.
+COPY 3.9/root/opt/wheels /opt/wheels
 # - Create a Python virtual environment for use by any application to avoid
 #   potential conflicts with Python packages preinstalled in the main Python
 #   installation.
@@ -58,6 +64,17 @@ COPY ./root/ /
 #   writable as OpenShift default security model is to run the container
 #   under random UID.
 RUN python3.9 -m venv ${APP_ROOT} && \
+# Python 3 only code, Python 2 installs pip from PyPI in the assemble script. \
+# We have to upgrade pip to a newer verison because: \
+# * pip < 9 does not support different packages' versions for Python 2/3 \
+# * pip < 19.3 does not support manylinux2014 wheels. Only manylinux2014 (and later) wheels \
+#   support platforms like ppc64le, aarch64 or armv7 \
+# We are newly using wheel from one of the latest stable Fedora releases (from RPM python-pip-wheel) \
+# because it's tested better then whatever version from PyPI and contains useful patches. \
+# We have to do it here (in the macro) so the permissions are correctly fixed and pip is able \
+# to reinstall itself in the next build phases in the assemble script if user wants the latest version \
+${APP_ROOT}/bin/pip install /opt/wheels/pip-* && \
+rm -r /opt/wheels && \
 chown -R 1001:0 ${APP_ROOT} && \
 fix-permissions ${APP_ROOT} -P
 
diff --git a/README.md b/README.md
index 425d199..2491fae 100644
--- a/README.md
+++ b/README.md
@@ -260,12 +260,18 @@ file inside your source code repository.
     the custom index, the container will try to install/update them from
     upstream PyPI afterwards.
 
+* **PORT**
+
+    HTTP(S) port your application should listen on. The default is 8080.
+    `PORT` is used only for Django development server and for Gunicorn
+    with the default configutation (no `APP_CONFIG` or `GUNICORN_CMD_ARGS` specified).
+
 * **UPGRADE_PIP_TO_LATEST**
 
     Set this variable to a non-empty value to have the 'pip' program and related
     python packages (setuptools and wheel) be upgraded to the most recent version
-    before any Python packages are installed. If not set it will use whatever
-    the default version is included by the platform for the Python version being used.
+    before any Python packages are installed. If not set, the container will use
+    the stable pip version this container was built with, taken from a recent Fedora release.
 
 * **WEB_CONCURRENCY**
 
@@ -323,6 +329,9 @@ following ways, in precedence order:
   If you have both Django and Gunicorn in your requirements, your Django project
   will automatically be served using Gunicorn.
 
+  The default setting for Gunicorn (`--bind=0.0.0.0:$PORT --access-logfile=-`) is applied
+  only if both `$APP_CONFIG` and `$GUNICORN_CMD_ARGS` are not defined.
+
 * **Django development server**
 
   If you have Django in your requirements but don't have Gunicorn, then your
diff --git a/root/opt/wheels/pip-21.0.1-py3-none-any.whl b/root/opt/wheels/pip-21.0.1-py3-none-any.whl
new file mode 100755
index 0000000..87a37e6
Binary files /dev/null and b/root/opt/wheels/pip-21.0.1-py3-none-any.whl differ
diff --git a/s2i/bin/assemble b/s2i/bin/assemble
index 10996be..3d36bdd 100755
--- a/s2i/bin/assemble
+++ b/s2i/bin/assemble
@@ -53,20 +53,11 @@ mv /tmp/src/* "$HOME"
 # set permissions for any installed artifacts
 fix-permissions /opt/app-root -P
 
-# We have to first upgrade pip to at least 19.3 because:
-# * pip < 9 does not support different packages' versions for Python 2/3
-# * pip < 19.3 does not support manylinux2014 wheels. Only manylinux2014 wheels
-#   support platforms like ppc64le, aarch64 or armv7
-echo "---> Upgrading pip to version 19.3.1 ..."
-if ! pip install -U "pip==19.3.1"; then
-  echo "WARNING: Installation of 'pip==19.3.1' failed, trying again from official PyPI with pip --isolated install"
-  pip install --isolated -U "pip==19.3.1"
-fi
 
 if [[ ! -z "$UPGRADE_PIP_TO_LATEST" ]]; then
-  echo "---> Upgrading pip to latest version ..."
+  echo "---> Upgrading pip, setuptools and wheel to latest version ..."
   if ! pip install -U pip setuptools wheel; then
-    echo "WARNING: Installation of the latest pip,setuptools and wheel failed, trying again from official PyPI with pip --isolated install"
+    echo "WARNING: Installation of the latest pip, setuptools and wheel failed, trying again from official PyPI with pip --isolated install"
     pip install --isolated -U pip setuptools wheel
   fi
 fi
diff --git a/s2i/bin/run b/s2i/bin/run
index b5c2441..21a38f4 100755
--- a/s2i/bin/run
+++ b/s2i/bin/run
@@ -93,6 +93,11 @@ if should_migrate; then
   fi
 fi
 
+# If not set, use 8080 as the default port
+if [ -z "$PORT" ]; then
+  PORT=8080
+fi
+
 if is_gunicorn_installed; then
   setup_py=$(find "$HOME" -maxdepth 2 -type f -name 'setup.py' -print -quit)
   # Look for wsgi module in the current directory
@@ -105,17 +110,27 @@ if is_gunicorn_installed; then
   if [[ "$APP_MODULE" ]]; then
     export WEB_CONCURRENCY=${WEB_CONCURRENCY:-$(get_default_web_concurrency)}
 
-    echo "---> Serving application with gunicorn ($APP_MODULE) ..."
-    exec gunicorn "$APP_MODULE" --bind=0.0.0.0:8080 --access-logfile=- --config "$APP_CONFIG"
+    # Default settings for gunicorn if none of the custom are set
+    if [ -z "$APP_CONFIG" ] && [ -z "$GUNICORN_CMD_ARGS" ]; then
+      GUNICORN_CMD_ARGS="--bind=0.0.0.0:$PORT --access-logfile=-"
+      gunicorn_settings_source="default"
+    else
+      gunicorn_settings_source="custom"
+    fi
+
+    # Gunicorn can read GUNICORN_CMD_ARGS as an env variable but because this is not
+    # supported in Gunicorn < 20 we still need for Python 2, we are using arguments directly.
+    echo "---> Serving application with gunicorn ($APP_MODULE) with $gunicorn_settings_source settings ..."
+    exec gunicorn "$APP_MODULE" $GUNICORN_CMD_ARGS --config "$APP_CONFIG"
   fi
 fi
 
 if is_django_installed; then
   if [[ -f "$manage_file" ]]; then
-    echo "---> Serving application with 'manage.py runserver' ..."
+    echo "---> Serving application with 'manage.py runserver 0.0.0.0:$PORT' ..."
     echo "WARNING: this is NOT a recommended way to run you application in production!"
     echo "Consider using gunicorn or some other production web server."
-    maybe_run_in_init_wrapper python "$manage_file" runserver 0.0.0.0:8080
+    maybe_run_in_init_wrapper python "$manage_file" runserver 0.0.0.0:$PORT
   else
     echo "WARNING: seems that you're using Django, but we could not find a 'manage.py' file."
     echo "Skipped 'python manage.py runserver'."
diff --git a/test/django-different-port-test-app/.gitignore b/test/django-different-port-test-app/.gitignore
new file mode 100644
index 0000000..651f49f
--- /dev/null
+++ b/test/django-different-port-test-app/.gitignore
@@ -0,0 +1,61 @@
+# Django
+db.sqlite3
+staticfiles/
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
diff --git a/test/django-different-port-test-app/.s2i/environment b/test/django-different-port-test-app/.s2i/environment
new file mode 100644
index 0000000..990affa
--- /dev/null
+++ b/test/django-different-port-test-app/.s2i/environment
@@ -0,0 +1 @@
+PORT=8085
diff --git a/test/django-different-port-test-app/manage.py b/test/django-different-port-test-app/manage.py
new file mode 100755
index 0000000..82cfa83
--- /dev/null
+++ b/test/django-different-port-test-app/manage.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+import os
+import sys
+
+if __name__ == "__main__":
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")
+
+    from django.core.management import execute_from_command_line
+
+    execute_from_command_line(sys.argv)
diff --git a/test/django-different-port-test-app/project/__init__.py b/test/django-different-port-test-app/project/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/test/django-different-port-test-app/project/settings.py b/test/django-different-port-test-app/project/settings.py
new file mode 100644
index 0000000..5827794
--- /dev/null
+++ b/test/django-different-port-test-app/project/settings.py
@@ -0,0 +1,104 @@
+"""
+Django settings for project project.
+
+Generated by 'django-admin startproject' using Django 1.8.1.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/1.8/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/1.8/ref/settings/
+"""
+
+# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
+import os
+
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/1.8/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = 'y*b^6p#z&cm2)8rzgbp2i4k*+rg2h%60l*bmf6hg&ro!z0-ael'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+# SECURITY WARNING: do not use '*' on production or use some HTTP(S) proxy
+ALLOWED_HOSTS = ['*']
+
+
+# Application definition
+
+INSTALLED_APPS = (
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+)
+
+MIDDLEWARE_CLASSES = (
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+    'django.middleware.security.SecurityMiddleware',
+)
+
+ROOT_URLCONF = 'project.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'project.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/1.8/ref/settings/#databases
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+    }
+}
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/1.8/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/1.8/howto/static-files/
+
+STATIC_URL = '/static/'
+STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')
diff --git a/test/django-different-port-test-app/project/urls.py b/test/django-different-port-test-app/project/urls.py
new file mode 100644
index 0000000..b5e472c
--- /dev/null
+++ b/test/django-different-port-test-app/project/urls.py
@@ -0,0 +1,21 @@
+"""project URL Configuration
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/1.8/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  url(r'^$', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  url(r'^$', Home.as_view(), name='home')
+Including another URLconf
+    1. Add an import:  from blog import urls as blog_urls
+    2. Add a URL to urlpatterns:  url(r'^blog/', include(blog_urls))
+"""
+from django.conf.urls import include, url
+from django.contrib import admin
+
+urlpatterns = [
+    url(r'^admin/', include(admin.site.urls)),
+]
diff --git a/test/django-different-port-test-app/project/wsgi.py b/test/django-different-port-test-app/project/wsgi.py
new file mode 100644
index 0000000..7c2f625
--- /dev/null
+++ b/test/django-different-port-test-app/project/wsgi.py
@@ -0,0 +1,16 @@
+"""
+WSGI config for project project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/1.8/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")
+
+application = get_wsgi_application()
diff --git a/test/django-different-port-test-app/requirements.txt b/test/django-different-port-test-app/requirements.txt
new file mode 100644
index 0000000..30eb621
--- /dev/null
+++ b/test/django-different-port-test-app/requirements.txt
@@ -0,0 +1 @@
+Django==1.11.29
diff --git a/test/gunicorn-config-different-port-test-app/.gitignore b/test/gunicorn-config-different-port-test-app/.gitignore
new file mode 100644
index 0000000..ba74660
--- /dev/null
+++ b/test/gunicorn-config-different-port-test-app/.gitignore
@@ -0,0 +1,57 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
diff --git a/test/gunicorn-config-different-port-test-app/.s2i/environment b/test/gunicorn-config-different-port-test-app/.s2i/environment
new file mode 100644
index 0000000..d975f74
--- /dev/null
+++ b/test/gunicorn-config-different-port-test-app/.s2i/environment
@@ -0,0 +1,2 @@
+APP_MODULE=app:application
+APP_CONFIG=./gunicorn.conf.py
diff --git a/test/gunicorn-config-different-port-test-app/app.py b/test/gunicorn-config-different-port-test-app/app.py
new file mode 100644
index 0000000..09fee1b
--- /dev/null
+++ b/test/gunicorn-config-different-port-test-app/app.py
@@ -0,0 +1,4 @@
+
+def application(environ, start_response):
+    start_response('200 OK', [('Content-Type','text/plain')])
+    return [b"Hello from gunicorn WSGI application!"]
diff --git a/test/gunicorn-config-different-port-test-app/gunicorn.conf.py b/test/gunicorn-config-different-port-test-app/gunicorn.conf.py
new file mode 100644
index 0000000..1ae0446
--- /dev/null
+++ b/test/gunicorn-config-different-port-test-app/gunicorn.conf.py
@@ -0,0 +1,4 @@
+import multiprocessing
+
+bind = "0.0.0.0:8085"
+workers = multiprocessing.cpu_count() * 2 + 1
diff --git a/test/gunicorn-config-different-port-test-app/requirements.txt b/test/gunicorn-config-different-port-test-app/requirements.txt
new file mode 100644
index 0000000..268bd60
--- /dev/null
+++ b/test/gunicorn-config-different-port-test-app/requirements.txt
@@ -0,0 +1,2 @@
+gunicorn<20.0.0; python_version < '3.5'
+gunicorn>=20.0.0; python_version >= '3.5'
\ No newline at end of file
diff --git a/test/gunicorn-different-port-test-app/.gitignore b/test/gunicorn-different-port-test-app/.gitignore
new file mode 100644
index 0000000..ba74660
--- /dev/null
+++ b/test/gunicorn-different-port-test-app/.gitignore
@@ -0,0 +1,57 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
diff --git a/test/gunicorn-different-port-test-app/.s2i/environment b/test/gunicorn-different-port-test-app/.s2i/environment
new file mode 100644
index 0000000..164666b
--- /dev/null
+++ b/test/gunicorn-different-port-test-app/.s2i/environment
@@ -0,0 +1,2 @@
+APP_MODULE=app:application
+PORT=8085
diff --git a/test/gunicorn-different-port-test-app/app.py b/test/gunicorn-different-port-test-app/app.py
new file mode 100644
index 0000000..09fee1b
--- /dev/null
+++ b/test/gunicorn-different-port-test-app/app.py
@@ -0,0 +1,4 @@
+
+def application(environ, start_response):
+    start_response('200 OK', [('Content-Type','text/plain')])
+    return [b"Hello from gunicorn WSGI application!"]
diff --git a/test/gunicorn-different-port-test-app/requirements.txt b/test/gunicorn-different-port-test-app/requirements.txt
new file mode 100644
index 0000000..268bd60
--- /dev/null
+++ b/test/gunicorn-different-port-test-app/requirements.txt
@@ -0,0 +1,2 @@
+gunicorn<20.0.0; python_version < '3.5'
+gunicorn>=20.0.0; python_version >= '3.5'
\ No newline at end of file
diff --git a/test/run b/test/run
index d14e9a7..291c3df 100755
--- a/test/run
+++ b/test/run
@@ -6,7 +6,7 @@
 # IMAGE_NAME specifies a name of the candidate image used for testing.
 # The image has to be available before this script is executed.
 #
-declare -a WEB_APPS=({standalone,setup,setup-requirements,django,numpy,app-home,npm-virtualenv-uwsgi,locale,mod-wsgi,pipenv,pipenv-and-micropipenv-should-fail,pin-pipenv-version,app-module,micropipenv,micropipenv-requirements}-test-app)
+declare -a WEB_APPS=({gunicorn-config-different-port,gunicorn-different-port,django-different-port,standalone,setup,setup-requirements,django,numpy,app-home,npm-virtualenv-uwsgi,locale,mod-wsgi,pipenv,pipenv-and-micropipenv-should-fail,pin-pipenv-version,app-module,micropipenv,micropipenv-requirements}-test-app)
 
 # TODO: Make command compatible for Mac users
 test_dir="$(readlink -zf $(dirname "${BASH_SOURCE[0]}"))"
@@ -37,9 +37,6 @@ IMAGE_NAME=${IMAGE_NAME:-centos/python-${VERSION//./}-centos7}
 
 . test/test-lib.sh
 
-# TODO: This should be part of the image metadata
-test_port=8080
-
 info() {
   echo -e "\n\e[1m[INFO] $@\e[0m\n"
 }
@@ -294,6 +291,13 @@ for app in ${@:-${WEB_APPS[@]}}; do
   # it from Docker hub
   s2i_args="--pull-policy=never"
 
+  # Example apps with "-different-port-" in their name don't use the default port 8080
+  if [[ "$app" == *"-different-port-"* ]]; then
+    test_port=8085
+  else
+    test_port=8080
+  fi
+
   prepare ${app}
   run_s2i_build ${app}
   RESULT=$?