mod_wsgi is configured with python2 on centOS when python3 is enabled

[lina He]

I was configuring the stable/train horizon on CentOS using devstack and set USE_PYTHON3=True.

I got below error in /var/log/httpd/horizon_error.log.

2020-04-14 06:52:32.116948 mod_wsgi (pid=22756): Target WSGI script '/opt/stack/horizon/openstack_dashboard/wsgi.py' cannot be loaded as Python module.
2020-04-14 06:52:32.117028 mod_wsgi (pid=22756): Exception occurred processing WSGI script '/opt/stack/horizon/openstack_dashboard/wsgi.py'.
2020-04-14 06:52:32.117059 Traceback (most recent call last):
2020-04-14 06:52:32.117097 File "/opt/stack/horizon/openstack_dashboard/wsgi.py", line 21, in <module>
2020-04-14 06:52:32.117188 from django.core.wsgi import get_wsgi_application
2020-04-14 06:52:32.117216 ImportError: No module named django.core.wsgi

The django module is installed in python3 lib. But the mod_wsgi is configured with python2 based on the /var/log/httpd/error_log.

[Tue Apr 14 08:17:23.504300 2020] [mpm_worker:notice] [pid 7881:tid 140070784944256] AH00292: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips mod_wsgi/3.4 Python/2.7.5 configured -- resuming normal operations
[Tue Apr 14 08:17:23.504338 2020] [core:notice] [pid 7881:tid 140070784944256] AH00094: Command line: '/usr/sbin/httpd -D FOREGROUND'

I checked the devstack/lib/apache code, the mod_wsgi is installed for fedora without python3 considering. I think it should check python3 and install corresponding mod_wsgi for it on fedora devstack same as the work for ubuntu.

function install_apache_wsgi {
    # Apache installation, because we mark it NOPRIME
    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
        fi
    elif is_fedora; then
        sudo rm -f /etc/httpd/conf.d/000-*
        install_package httpd mod_wsgi
        # For consistency with Ubuntu, switch to the worker mpm, as
        # the default is event
        sudo sed -i '/mod_mpm_prefork.so/s/^/#/g' /etc/httpd/conf.modules.d/00-mpm.conf
        sudo sed -i '/mod_mpm_event.so/s/^/#/g' /etc/httpd/conf.modules.d/00-mpm.conf
        sudo sed -i '/mod_mpm_worker.so/s/^#//g' /etc/httpd/conf.modules.d/00-mpm.conf

[Dr. Jens Harbott (j-harbott)]

Centos 7 is no longer supported on master/ussuri. If you can provide a patch for the train stable branch that fixed this, we can review it, but otherwise this will likely stay unresolved.

[Dr. Jens Harbott (j-harbott)]

Assuming that this is no longer relevant.