Nginx shows warning when running nginx -t: nginx: [warn] protocol options redefined for 203.0.113.2

Symptoms

• The following warning shows up when running
  nginx -t
  via CLI:

  # nginx -t
  
  nginx: [warn] protocol options redefined for 203.0.113.2:443 in /etc/nginx/plesk.conf.d/vhosts/example.com.conf:7
  
  nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
  
  nginx: configuration file /etc/nginx/nginx.conf test is successful

• Server preference http2 is enabled:

  # plesk bin http2_pref --status
  
  Enabled

• Preferred domain is set to
  example.com
  in
  Domains > example.com > Hosting & DNS > Hosting

• Running command
  plesk bin http2_pref --enable
  may fix the warning temporarily, but will show up again.

Cause

This was confirmed as a bug with ID
PPPM-14042
.

Since nginx 1.24 it is mandatory to specify http2 in every listen directive which does include the ssl option if http2 is enabled.

Resolution

Use Event Handlers to update nginx configuration files:

1. Connect to the server via
   SSH

2. Create and
   Edit file
   /root/update_nginx.sh
   that will be used by the Event Handler:

   #!/bin/bash
   
   vhostDir=$(grep VHOST /etc/psa/psa.conf | awk {'print $2'})
   
   if [ ! -z "$vhostDir" ] ; then
   
   sleep 15
   
   find $vhostDir/system/*/conf -type f -name "nginx.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
   
   find /etc/nginx/plesk.conf.d/webmails/ -type f -name "*.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
   
   find /etc/nginx -type f -name "*.conf" | xargs -i sed -i '/http2/!s/(listen [0-9.]*:443 ssl)/1 http2/' {}
   
   else
   
   echo "Vhost DIR fetch failed. Exiting ..." && exit 0
   
   fi

3. Set executable permissions to the script:

   # chmod +x /root/update_nginx.sh

4. Log into Plesk

5. Create Event Handler by going to
   Tools & Settings > Event Manager > Add Event Handler
   and add the following details:

   • Event: Physical hosting created
   • Priority: 50
   • User: root
   • Command: /root/update_nginx.sh

6. Repeate step 5 for Event: Physical hosting updated