Drop support for python2

python2 is EOL, let's move on and only support python3.

Change-Id: Ieffda4edea9cc19484c04420ed703f7141ef9f15

Author: jharbott

.zuul.yaml

@@ -558,9 +558,6 @@
       devstack_localrc:
         SERVICE_IP_VERSION: 6
         SERVICE_HOST: ""
-        # IPv6 and certificates known issue with python2
-        # https://bugs.launchpad.net/devstack/+bug/1794929
-        USE_PYTHON3: true
 
 - job:
     name: devstack-multinode

doc/source/configuration.rst

@@ -430,17 +430,6 @@ Python bindings added when they are enabled.
 
   ADDITIONAL_VENV_PACKAGES="python-foo, python-bar"
 
-Use python2
-------------
-
-By default ``stack.sh`` uses python3 (the exact version set by the
-``PYTHON3_VERSION``). This can be overriden so devstack will run
-python2 (the exact version set by ``PYTHON2_VERSION``).
-
-::
-
-  USE_PYTHON3=False
-
 A clean install every time
 --------------------------
 

doc/source/guides/devstack-with-lbaas-v2.rst

@@ -41,9 +41,6 @@ Edit your ``/opt/stack/devstack/local.conf`` to look like
     # If you are enabling barbican for TLS offload in Octavia, include it here.
     # enable_plugin barbican https://opendev.org/openstack/barbican
 
-    # If you have python3 available:
-    # USE_PYTHON3=True
-
     # ===== BEGIN localrc =====
     DATABASE_PASSWORD=password
     ADMIN_PASSWORD=password

inc/python

@@ -62,7 +62,7 @@ function get_python_exec_prefix {
     $xtrace
 
     local PYTHON_PATH=/usr/local/bin
-    ( is_fedora && ! python3_enabled ) || is_suse && PYTHON_PATH=/usr/bin
+    is_suse && PYTHON_PATH=/usr/bin
     echo $PYTHON_PATH
 }
 
@@ -169,16 +169,9 @@ function pip_install {
         local cmd_pip=$PIP_VIRTUAL_ENV/bin/pip
         local sudo_pip="env"
     else
-        local cmd_pip
-        local sudo_pip="sudo -H"
-        if python3_enabled; then
-            echo "Using python $PYTHON3_VERSION to install $package_dir because python3_enabled=True"
-            sudo_pip="$sudo_pip LC_ALL=en_US.UTF-8"
-            cmd_pip="python$PYTHON3_VERSION -m pip"
-        else
-            echo "Using python $PYTHON2_VERSION to install $package_dir because python3_enabled=False"
-            cmd_pip=$(get_pip_command $PYTHON2_VERSION)
-        fi
+        local cmd_pip="python$PYTHON3_VERSION -m pip"
+        local sudo_pip="sudo -H LC_ALL=en_US.UTF-8"
+        echo "Using python $PYTHON3_VERSION to install $package_dir"
     fi
 
     cmd_pip="$cmd_pip install"
@@ -213,14 +206,8 @@ function pip_uninstall {
         local cmd_pip=$PIP_VIRTUAL_ENV/bin/pip
         local sudo_pip="env"
     else
-        local cmd_pip
-        local sudo_pip="sudo -H"
-        if python3_enabled; then
-            sudo_pip="$sudo_pip LC_ALL=en_US.UTF-8"
-            cmd_pip="python$PYTHON3_VERSION -m pip"
-        else
-            cmd_pip=$(get_pip_command $PYTHON2_VERSION)
-        fi
+        local cmd_pip="python$PYTHON3_VERSION -m pip"
+        local sudo_pip="sudo -H LC_ALL=en_US.UTF-8"
     fi
     # don't error if we can't uninstall, it might not be there
     $sudo_pip $cmd_pip uninstall -y $name || /bin/true
@@ -457,37 +444,15 @@ function setup_package {
 }
 
 # Report whether python 3 should be used
+# TODO(frickler): drop this once all legacy uses are removed
 function python3_enabled {
-    if [[ $USE_PYTHON3 == "True" ]]; then
-        return 0
-    else
-        return 1
-    fi
+    return 1
 }
 
 # Provide requested python version and sets PYTHON variable
 function install_python {
-    # NOTE: install_python function should finally just do what install_python3
-    # does as soon Python 2 support has been dropped
-    if python3_enabled; then
-        install_python3
-        export PYTHON=$(which python${PYTHON3_VERSION} 2>/dev/null ||
-                        which python3 2>/dev/null)
-        if [[ "${DISTRO}" =~ (rhel8) ]]; then
-            # Use Python 3 as default python command so that we have only one
-            # python alternative to use on the system for either python and
-            # python3
-            sudo alternatives --set python "${PYTHON}"
-        else
-            # Install anyway Python 2 for legacy scripts that still requires
-            # python instead of python3 command
-            install_package python
-        fi
-    else
-        echo "WARNING - Python 2 support has been deprecated in favor of Python 3"
-        install_package python
-        export PYTHON=$(which python 2>/dev/null)
-    fi
+    install_python3
+    export PYTHON=$(which python${PYTHON3_VERSION} 2>/dev/null)
 }
 
 # Install python3 packages

lib/apache

@@ -89,11 +89,7 @@ function install_apache_uwsgi {
     #
     # For package installs, the distro ships both plugins and you need
     # to select the right one ... it will not be autodetected.
-    if python3_enabled; then
-        UWSGI_PYTHON_PLUGIN=python3
-    else
-        UWSGI_PYTHON_PLUGIN=python
-    fi
+    UWSGI_PYTHON_PLUGIN=python3
 
     if is_ubuntu; then
         local pkg_list="uwsgi uwsgi-plugin-python3 libapache2-mod-proxy-uwsgi"
@@ -150,14 +146,10 @@ function install_apache_wsgi {
     if is_ubuntu; then
         # Install apache2, which is NOPRIME'd
         install_package apache2
-        if python3_enabled; then
-            if is_package_installed libapache2-mod-wsgi; then
-                uninstall_package libapache2-mod-wsgi
-            fi
-            install_package libapache2-mod-wsgi-py3
-        else
-            install_package libapache2-mod-wsgi
+        if is_package_installed libapache2-mod-wsgi; then
+            uninstall_package libapache2-mod-wsgi
         fi
+        install_package libapache2-mod-wsgi-py3
     elif is_fedora; then
         sudo rm -f /etc/httpd/conf.d/000-*
         install_package httpd mod_wsgi

lib/tls

@@ -227,13 +227,7 @@ function init_CA {
 function init_cert {
     if [[ ! -r $DEVSTACK_CERT ]]; then
         if [[ -n "$TLS_IP" ]]; then
-            if python3_enabled; then
-                TLS_IP="IP:$TLS_IP"
-            else
-                # Lie to let incomplete match routines work with python2
-                # see https://bugs.python.org/issue23239
-                TLS_IP="DNS:$TLS_IP,IP:$TLS_IP"
-            fi
+            TLS_IP="IP:$TLS_IP"
             if [[ -n "$HOST_IPV6" ]]; then
                 TLS_IP="$TLS_IP,IP:$HOST_IPV6"
             fi

stackrc

@@ -134,25 +134,17 @@ if [[ -r $RC_DIR/.localrc.password ]]; then
 fi
 
 # Control whether Python 3 should be used at all.
-export USE_PYTHON3=$(trueorfalse True USE_PYTHON3)
+# TODO(frickler): Drop this when all consumers are fixed
+export USE_PYTHON3=True
 
-# When Python 3 is supported by an application, adding the specific
-# version of Python 3 to this variable will install the app using that
-# version of the interpreter instead of 2.7.
+# Adding the specific version of Python 3 to this variable will install
+# the app using that version of the interpreter instead of just 3.
 _DEFAULT_PYTHON3_VERSION="$(_get_python_version python3)"
 export PYTHON3_VERSION=${PYTHON3_VERSION:-${_DEFAULT_PYTHON3_VERSION:-3}}
 
-# Just to be more explicit on the Python 2 version to use.
-_DEFAULT_PYTHON2_VERSION="$(_get_python_version python2)"
-export PYTHON2_VERSION=${PYTHON2_VERSION:-${_DEFAULT_PYTHON2_VERSION:-2.7}}
-
 # Create a virtualenv with this
-if [[ ${USE_PYTHON3} == True ]]; then
-    # Use the built-in venv to avoid more dependencies
-    export VIRTUALENV_CMD="python3 -m venv"
-else
-    export VIRTUALENV_CMD="virtualenv "
-fi
+# Use the built-in venv to avoid more dependencies
+export VIRTUALENV_CMD="python3 -m venv"
 
 # Default for log coloring is based on interactive-or-not.
 # Baseline assumption is that non-interactive invocations are for CI,

tools/install_pip.sh

@@ -92,9 +92,6 @@ function install_get_pip {
         touch $LOCAL_PIP.downloaded
     fi
     sudo -H -E python${PYTHON3_VERSION} $LOCAL_PIP
-    if ! python3_enabled; then
-        sudo -H -E python $LOCAL_PIP
-    fi
 }
 
 
@@ -142,9 +139,6 @@ fi
 # results in a nonfunctional system. pip on fedora installs to /usr so pip
 # can safely override the system pip for all versions of fedora
 if ! is_fedora  && ! is_suse; then
-    if is_package_installed python-pip ; then
-        uninstall_package python-pip
-    fi
     if is_package_installed python3-pip ; then
         uninstall_package python3-pip
     fi