must install ssh, telnet not secure even password
=================================================
ssh -l root 99.999.999.99


install fail2ban
==================
sudo apt install fail2ban
systemctl status fail2ban.service
sudo systemctl enable fail2ban
sudo systemctl start fail2ban
sudo systemctl status fail2ban

automatically upgrade debian linux
===================================
sudo apt-get install unattended-upgrades apt-listchanges
sudo apt-get install unattended-upgrades
sudo dpkg-reconfigure -plow unattended-upgrades


Install nginx
=============
sudo apt-get install nginx -y
sudo systemctl start nginx
sudo systemctl enable nginx

cat /etc/nginx/sites-enabled/default
cat /etc/nginx/sites-available/default


certbot ssl
============
sudo apt install snapd
sudo snap install core
sudo snap refresh core
sudo snap install --classic certbot
sudo ln -s /snap/bin/certbot /usr/bin/certbot
sudo certbot --nginx --agree-tos --redirect --email root@xxx.ca -d xxx.ca -d www.xxx.ca

upload files for static website
================================
/var/www/html

run process in background without hangingup or killing on exit
===============================================================
nohup bash-command &



to make it dynamic install php
=================================
sudo apt-get install php8.2-sqlite3
sudo apt-get install php php-fpm php-curl php-cli php-zip php-mysql php-xml -y
php -v
sudo systemctl status php7.4-fpm or php8.2-fpm
sudo nano /etc/nginx/sites-available/default
add index.php to index section in both 80/443 places otherwise will have 403 forbidden error
uncomment php section and apache section, leave the 9000 port section commented
must uncomment in both http 80 and https section 443

        index index.html index.htm index.nginx-debian.html index.php;
    server_name xxx.ca www.xxx.ca; # managed by Certbot


        location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ =404;
        }

        # pass PHP scripts to FastCGI server
        #
        location ~ \.php$ {
                include snippets/fastcgi-php.conf;
        #
        #       # With php-fpm (or other unix sockets):
                fastcgi_pass unix:/run/php/php8.2-fpm.sock;
        #       # With php-cgi (or other tcp sockets):
        #       fastcgi_pass 127.0.0.1:9000;
        }



nginx -t
sudo service nginx reload
sudo chmod -R 755 /var/www/html
echo "<?php phpinfo(); ?>" >> /var/www/html/info.php
test but delete phpinfo file afterwards, since security risk
ls -la to see if have x for info.php
chmod 755 info.php or
recursively 
sudo chmod -R 755 /var/www/html
4=read
2=write
1=execute

echo -e "User-agent: *\nAllow: /" > robots.txt

sudo chmod -R 755 /var/www/html
sudo systemctl restart nginx

log files are at cat /var/log/nginx/error.log.1 access.log and 

sqlite3 database
==================
sudo apt-get install sqlite3

sudo apt-get install php8.2-sqlite3
sqlite3 data.db "CREATE TABLE posts ( id INTEGER PRIMARY KEY AUTOINCREMENT, hash_name TEXT,
  ip_address TEXT,
  parent_id INTEGER,
  text TEXT NOT NULL,
  date_posted DATETIME DEFAULT CURRENT_TIMESTAMP,
  isSpam INTEGER DEFAULT 0
);"

sqlite3 data.db
.schema
.exit

sudo chmod -R 755 /var/www/html
database might not write

need to give ownership over the database to nginx php
otherwise database will not write


see user 
sudo ps aux | grep nginx 
or php should be both www-data

sudo chown www-data:www-data /var/www/html/
sudo chown www-data:www-data /var/www/html/data.db
both owner of folder and fille required to write to database


rotate logs
============
sudo apt-get install logrotate

turn off nginx logs
=====================
nano /etc/nginx/nginx.conf
add in the http area
error_log /dev/null crit;
access_log off;

copy directory over ssh
=======================
scp -r /home/to/local/source user@ssh.example.com:/home/to/remote/destination 


download directory over ssh
===========================
scp -r user@ssh.example.com:/home/to/remote/source /path/to/local/destination


logout
=======
logout