NginX reverse proxy with iRedMail Apache2

Question

On an empty VPS hosting, I managed to run the base iRedMail installation with Apache2 and LDAP and my roundcubemail was accessible at:
https://www.mydomain.com/mail

then I installed NginX, shutdown Apache2, reconfigured iRedMail (without adding any extra A record in the DNS entry) and managed to run it on NginX base installation as well with roundcubemail accessible at:
https://mail.mydomain.com

Now, I want to run NginX reverse proxy with the base iRedMail Apache2 installation with roundcubemail accessible at:
https://mail.mydomain.com
and I'm kinda stuck with the following Apache2 config files:
/etc/apache2/ports.conf

Listen 8080

/etc/apahce2/sites-available/my-iredmail.conf

<VirtualHost *:8080>
DocumentRoot /var/www/
ServerName mail.mydomain.com

Alias / "/usr/share/apache2/roundcubemail/"
<Directory "/usr/share/apache2/roundcubemail">
Options Indexes FollowSymlinks MultiViews
AllowOverride All
Order allow,deny
Allow from all
</Directory>
</VirtualHost>

and following NginX config file:

/etc/nginx/sites-available/default

server {
listen 80 default_server;
listen [::]:80;

    root /usr/share/nginx/html;
    index index.html index.htm index.php;

    server_name mydomain.com www.mydomain.com mail.mydomain.com;

    location / {
            try_files $uri $uri/ /index.html;
    }

    location ~ \.php$ {
            proxy_set_header X-Real-IP  $remote_addr;
            proxy_set_header X-Forwarded-For $remote_addr;
            proxy_set_header Host $host;
            proxy_pass http://127.0.0.1:8080/;
    }

    location ~ /\.ht {
            deny all;
    }

}

server {
listen 443 ssl;

    root /var/www;
    index index.html index.htm index.php;

    server_name mydomain.com www.mydomain.com mail.mydomain.com;

    ssl                  on;
    ssl_certificate      /etc/ssl/certs/iRedMail_CA.pem;
    ssl_certificate_key  /etc/ssl/private/iRedMail.key;
    ssl_session_timeout  5m;
    ssl_protocols  SSLv2 SSLv3 TLSv1;
    ssl_ciphers  ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
    ssl_prefer_server_ciphers   on;

    location / {
            # Apache is listening here
            proxy_pass http://127.0.0.1:8080/;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   }

}

Hitting in browser:
https://mail.mydomain.com gives the usual SSL Connection Error.
Kindly advise.

Answer 1

Your problem is here:

location ~ \.php$ {
        proxy_set_header X-Real-IP  $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header Host $host;
        proxy_pass http://127.0.0.1:8080/;
}

You cannot use proxy_pass in a location that is not static. You should do it the other way around. Make a list of things that shall be loaded locally by nginx and then pass the location / using proxy_pass back to Apache.