Service subdomains webmail/cpanel/webdisk/whm return error 502 when using ea-nginx as reverse proxy

Symptoms

When accessing webmail.domain.tld:2096 to access webmail using a service subdomains it will return 502 error.

Cause

Possible causes are the recent updates of our apache and ea-nginx packages.

easyapache-4-change-log-25

We have opened an internal case with ID: CPANEL-53948  and our developers are looking into it as we speak.

Make sure to follow this article for any updates on the resolution.

Resolution

To apply the workaround please follow the below steps:

1. Log in to WHM as root
2. Navigate to Home / Service Configuration / Apache Configuration / Include Editor.
3. Under Pre VirtualHost Include, select the All Apache versions.

4. Add the below code

   CONFIG_TEXT: SetEnvIf Host "^(webmail|cpanel|whm|webdisk)\." proxy-nokeepalive=1 
   SetEnvIf Host "^(webmail|cpanel|whm|webdisk)\." proxy-initial-not-pooled=1

5. Click Update.
6. Click Restart Apache.