Configure local services to run within the same domain with Nginx

There are 2 different web servers that are deployed under the same domain (example.com and api.example.com)

I want to use httpOnly cookie shared across these 2 sites.

There is such local configuration:

1. https://local.example.com + IIS Express + ASP MVC
2. https://localhost:8888 or https://api-local.example.com:8888 + .net core

Eventually, there are lots of limitations that can not be passed:

• change domain names
• host both apps in a single IIS

I was looking to configure Nginx that would proxy

• https://local.example.com:943 to https://local.example.com
• https://api-local.example.com:943 to https://api-local.example.com:8888

In common, this works for the .net core API, and I can use Postman to query the data over the Nginx self-signed certificate.

But I can't get it working for the IIS one. Chrome shows the alert and blocks the website

I'm using such nginx configuration

events {}

http {
  server {
    listen 943 ssl;
    listen [::]:943 ssl;
    server_name  api-local.example.com;

    ssl_certificate /etc/nginx/ss.crt;
    ssl_certificate_key /etc/nginx/ss.key;

    location / {
      proxy_pass https://host.docker.internal:8888;
      proxy_set_header Host $host;
    }
  } 

  server {
    listen 943 ssl;
    listen [::]:943 ssl;
    server_name  example.com;

    ssl_certificate /etc/nginx/ss.crt;
    ssl_certificate_key /etc/nginx/ss.key;

    location / {
        proxy_pass https://host.docker.internal;
        proxy_set_header Host $host;
    }
  } 
}

and generating the key in a similar to this way:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ss.key -out ss.crt -config san.conf


// san.conf

[req]
default_bits       = 2048
default_keyfile    = ss.key
distinguished_name = req_distinguished_name
req_extensions     = req_ext
x509_extensions    = v3_ca

[req_distinguished_name]
countryName                 = Country Name (2 letter code)
countryName_default         = US
stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = New York
localityName                = Locality Name (eg, city)
localityName_default        = Rochester
organizationName            = Organization Name (eg, company)
organizationName_default    = local.example.com
organizationalUnitName      = organizationalunit
organizationalUnitName_default = Development
commonName                  = Common Name (e.g. server FQDN or YOUR name)
commonName_default          = local.example.com
commonName_max              = 64

[req_ext]
subjectAltName = @alt_names

[v3_ca]
subjectAltName = @alt_names

[alt_names]
DNS.1   = local.example.com
DNS.2   = api-local.example.com