NGINX configuration for CORS and proper HTTPS rerouting - nginx

Question

Hi I'm quite inexperienced with NGINX and am having difficulty understanding why things aren't working as expected. I'm trying to test an API that I made with a docker container, which is being run with the command: docker run -d -v $(pwd):/app -p 8080:8000 --rm wiseeast/ya_bot.
I'm able to make API requests with Postman at http://ffpr.isi.edu:8080/api with a POST request, but the same request on AJAX with javascript returns an apparently frequent No 'Access-Control-Allow-Origin' header is present on the requested resource. error. I tried to bypass this by enabling CORS on my server by adding add_header 'Access-Control-Allow-Origin' '*' always; because I have control over it but it didn't resolve the issue. Also what is bugging me is that with Postman I can make a successful POST request to http://ffpr.isi.edu:8080/api but not to https://ffpr.isi.edu:8080/api.
Also, I have a rerouting issue that I feel should be straightforward given what I've read but isn't working. I have a webpage properly rerouting http://ffpr.isi.edu to https://ffpr.isi.edu but the rest of the rerouting doesn't work. For instance http://ffpr.isi.edu:5050/ loads through port 80 unsecurely and won't reroute to https://ffpr.isi.edu:5050/. On the other hand, https://ffpr.isi.edu:5050/ won't open at all with a time out error.
Here is my full nginx.conf file:
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
http {
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
# Load modular configuration files from the /etc/nginx/conf.d directory.
# See http://nginx.org/en/docs/ngx_core_module.html#include
# for more information.
include /etc/nginx/conf.d/*.conf;
upstream frontend {
server 0.0.0.0:8000;
}
upstream ased_api {
server 0.0.0.0:5000;
}
upstream ya_bot {
server 0.0.0.0:8080;
}
upstream yesand {
server 0.0.0.0:5050;
}
server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
root /usr/share/nginx/html;
return 301 https://$host$request_uri;
}
# Settings for a TLS enabled server.
#
server {
listen 443 ssl http2;
listen [::]:443 ssl http2;
server_name ffpr.isi.edu;
ssl_certificate "/etc/nginx/ssl/ffpr_isi_edu_cert.cer";
ssl_certificate_key "/etc/nginx/ssl/ffpr_isi_edu.key";
ssl_session_cache shared:SSL:1m;
ssl_session_timeout 10m;
ssl_ciphers HIGH:!aNULL:!MD5;
ssl_prefer_server_ciphers on;
# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
location / {
add_header 'Access-Control-Allow-Origin' '*';
proxy_pass http://frontend;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
location /api {
proxy_pass http://ased_api;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
location /ya_bot {
proxy_pass http://ya_bot;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
add_header 'Access-Control-Allow-Origin' '*' always;
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
}
location /yesand {
add_header 'Access-Control-Allow-Origin' '*';
proxy_pass http://yesand;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
}
server {
listen 443 ssl http2 default_server;
listen [::]:443 ssl http2 default_server;
server_name _;
root /usr/share/nginx/html;
ssl_certificate "/etc/nginx/ssl/ffpr_isi_edu_cert.cer";
ssl_certificate_key "/etc/nginx/ssl/ffpr_isi_edu.key";
ssl_session_cache shared:SSL:1m;
ssl_session_timeout 10m;
ssl_ciphers HIGH:!aNULL:!MD5;
ssl_prefer_server_ciphers on;
# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
location / {
}
error_page 404 /404.html;
location = /40x.html {
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
}
}
}
I've been suffering with these issues for so long, any pointers are greatly appreciated!!

Answer 1

In my experience, the add_header 'Access-Control-Allow-Origin' '*'; on the proxy machine did not fix the problem.
However, setting the 'Access-Control-Allow-Origin' header from the backend API as a response header did work. For example, You can run the following Go code on the backend API:
(*w).Header().Set(“Access-Control-Allow-Credentials”, “proxy-host-name”)
As for the redirect issue, you don’t need to use two separate server blocks, try this instead in the nginx.conf:
server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
listen 443 ssl http2;
listen [::]:443 ssl http2;
server_name ffpr.isi.edu;
ssl_certificate "/etc/nginx/ssl/ffpr_isi_edu_cert.cer";
ssl_certificate_key "/etc/nginx/ssl/ffpr_isi_edu.key";
ssl_session_cache shared:SSL:1m;
ssl_session_timeout 10m;
ssl_ciphers HIGH:!aNULL:!MD5;
ssl_prefer_server_ciphers on;
if ($scheme != https) {
return 301 https://$host$request_uri
}
}
I hope this helps.