location direct domain.com to www.domain.com on multi site server - linux

Question

My server is running LEMP on Debian Jessie.
I am trying to force "www." to occur. I was able to do this with the following solution found on Stackoverflow.
return 301 http://www.example.com$request_uri;
However, I am running several websites from the server and the issue I am running into is as follows.
When logging into wordpress www.site1.com/wp-admin on one website, it routes me to www.site0.com/wp-admin. I believe this issue has to do with a default_server or hostname issue. Do I need to add all hostnames to /etc/hostname ?
Here is my host file
server {
listen 80 default_server;
listen [::]:80 default_server;
# SSL configuration
#
listen 443 ssl default_server;
listen [::]:443 ssl default_server;
root /var/www/site0;
index index.php index.html index.htm;
server_name site0.com;
#return 301 http://www.site0.com$request_uri;
location / {
try_files $uri $uri/ =404;
#try_files $uri $uri/ /index.html;
}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
# include snippets/fastcgi-php.conf;
#
# # With php5-cgi alone:
# fastcgi_pass 127.0.0.1:9000;
# # With php5-fpm:
fastcgi_pass unix:/var/run/php5-fpm.sock;
#fastcgi_index index.php
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
server {
listen 80;
listen [::]:80;
# SSL configuration
#listen 443 ssl;
#listen [::]:443 ssl;
root /var/www/site1;
index index.php index.html index.htm;
server_name site1.com;
#return 301 http://www.site1.com$request_uri;
location / {
try_files $uri $uri/ =404;
#try_files $uri $uri/ /index.html;
}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
# include snippets/fastcgi-php.conf;
#
# # With php5-cgi alone:
# fastcgi_pass 127.0.0.1:9000;
# # With php5-fpm:
fastcgi_pass unix:/var/run/php5-fpm.sock;
#fastcgi_index index.php
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi_params;
}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
I am thinking part of the issue has to do with:
listen 80 default_server;
listen [::]:80 default_server;
Please help if you can, it will be very much appreciate.

Answer 1

I found a very comprehensive guide here: https://www.digitalocean.com/community/tutorials/how-to-configure-single-and-multiple-wordpress-site-settings-with-nginx
The part you might find relevent is this:
# Rewrite rules for WordPress Multi-site.
if (!-e $request_filename) {
rewrite /wp-admin$ $scheme://$host$uri/ permanent;
rewrite ^/[_0-9a-zA-Z-]+(/wp-.*) $1 last;
rewrite ^/[_0-9a-zA-Z-]+(/.*\.php)$ $1 last;
}
Seems to be rewriting wordpress requests, specifically /wp-admin to the correct domain.