Same redirect works for one www to non-www domain, but create redirect loop for the second using nginx - .htaccess

Question

I have 2 Meteor apps using Nginx to redirect to different ports. For each app I have configuration files that are the same, but different ports and domains. First one redirects from www to non-www without any problem, but second one shows message :
This webpage has a redirect loop
In my-domain1.conf:
server {
server_name www.saveting.com;
return 301 $scheme://saveting.com$request_uri;
}
server {
listen 80;
server_name saveting.com www.saveting.com;
access_log /var/log/nginx/app.dev.access.log;
error_log /var/log/nginx/app.dev.error.log;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header X-Forwarded-For $remote_addr;
}
}
in the my-domain2.conf:
server {
server_name www.downloadinstagramvideo.com;
return 301 $scheme://downloadinstagramvideo.com$request_uri;
}
server {
listen 80;
server_name downloadinstragramvideo.com www.downloadinstagramvideo.com;
access_log /var/log/nginx/app.dev.access.log;
error_log /var/log/nginx/app.dev.error.log;
location / {
proxy_pass http://localhost:3001;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header X-Forwarded-For $remote_addr;
}
}
I tried to make one redirect for all domains using this tutorial, using following code:
server {
server_name "~^(?!www\.).*" ;
return 301 $scheme://www.$host$request_uri;
}
but that didn't work for any at all. What can cause redirect loop in the second one?

Answer 1

The server_name in the second/forth block includes the name of the first/third block, which is wrong. Each server block should have non-overlapping names. Such as:
server {
server_name www.saveting.com;
...
}
server {
server_name saveting.com;
...
}
server {
server_name www.downloadinstagramvideo.com;
...
}
server {
server_name downloadinstragramvideo.com;
...
}