Xen, xcpng
pfsense
LXC
forward proxy and reverse proxy
remote ssh , ssh tunneling
PowerDNS
Cluster Building
pwa -- Progressive Web Application
dig -- domain internet group
NodeRed

Host Subdomain and web-services

Buy a domain name, maybe leo.ai.
Go to PowerDNS, add subdomain abc, it will form abc.leo.ai. Associate the subdomain with ip address from aws.
Go to aws nginx-proxy ip2, add file abc.leo.ai to /etc/nginx/sites-enabled/. Just replace ip2 with localhost
Go to site-proxy ip3, add the same to the same folder, replace ip3 to ip4.


# You should look at the following URL's in order to grasp a solid understanding
# of Nginx configuration files in order to fully unleash the power of Nginx.
# https://www.nginx.com/resources/wiki/start/
# https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/
# https://wiki.debian.org/Nginx/DirectoryStructure
#
# In most cases, administrators will remove this file from sites-enabled/ and
# leave it as reference inside of sites-available where it will continue to be
# updated by the nginx packaging team.
#
# This file will automatically load configuration files provided by other
# applications, such as Drupal or Wordpress. These applications will be made
# available underneath a path with that package name, such as /drupal8.
#
# Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.
##

# Default server configuration
#
server {
        listen 80 default_server;
        listen [::]:80 default_server;

        # SSL configuration
        #
        # listen 443 ssl default_server;
        # listen [::]:443 ssl default_server;
        #
        # Note: You should disable gzip for SSL traffic.
        # See: https://bugs.debian.org/773332
        #
        # Read up on ssl_ciphers to ensure a secure configuration.
        # See: https://bugs.debian.org/765782
        #
        # Self signed certs generated by the ssl-cert package
        # Don't use them in a production server!
        #
        # include snippets/snakeoil.conf;

        root /var/www/html;
        # Add index.php to the list if you are using PHP
        index index.html index.htm index.nginx-debian.html;

        server_name abc.leo.ai;

        location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ =404;
                proxy_pass http://ip3:7000;
                proxy_set_header X-Forwarded-Proto http;
        }

        # Law Extractor
        location /lawex-api/ {
                proxy_pass http://ip3:7001/;
                proxy_set_header X-Forwarded-Proto http;
        }

        # location /


        # pass PHP scripts to FastCGI server
        #
        #location ~ \.php$ {
        #       include snippets/fastcgi-php.conf;
        #
        #       # With php-fpm (or other unix sockets):
        #       fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
        #       # With php-cgi (or other tcp sockets):
        #       fastcgi_pass 127.0.0.1:9000;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #       deny all;
        #}
}
# Virtual Host configuration for example.com
#
# You can move that to a different file under sites-available/ and symlink that
# to sites-enabled/ to enable it.
#
#server {
#       listen 80;
#       listen [::]:80;
#
#       server_name example.com;
#
#       root /var/www/example.com;
#       index index.html;
#
#       location / {
#               try_files $uri $uri/ =404;
#       }
#}

Go to firewall pfsense ip5 at browser, edit Services/DNS_Resolver/Custom_options, add 'local-data: "abc.leo.ai A ip3"'.
Refresh nginx. sudo nginx -s reload
Set up ssh tunnel between aws ip2 and ip4. ssh -i AWS_Linux.pem -R 7000:ip4:7000 ubuntu@ip2
Set up Flask with same ip4:7000.

Perfect hash function
Merkle tree
One-way function

Host Subdomain and web-services

References