modify basic filestructure

It's unclear what's 'basic', so `basic/` notes have been mostly moved.
The remainder became `shell/`.

networking/nginx.md

@@ -0,0 +1,110 @@
+---
+title: "nginx"
+tags: [ "networking", "web" ]
+---
+Install nginx:
+
+```sh
+sudo apt-get install nginx
+```
+
+```sh
+sudo apt-get enable --now nginx
+```
+
+Put a website somewhere:
+
+```sh
+mkdir /var/www/html/mysite/
+```
+
+Put an index file there:
+
+```sh
+vim /var/www/html/mysite/index.html
+```
+
+Make the owner `www-data`
+
+```sh
+chown -R www-data:www-data /var/www/html/mysite/
+```
+
+Make a configuration file for nginx:
+
+```sh
+vim /etc/nginx/sites-available/mysite.conf
+```
+
+
+```
+server {
+        listen 80;
+        listen [::]:80;
+        root /var/www/html/mysite;
+        index index.html index.htm;
+        server_name mysite.tk;
+
+   location / {
+       try_files $uri $uri/ =404;
+   }
+
+}
+```
+
+Make the site available:
+
+```sh
+ln -s /etc/nginx/sites-available/mysite.conf /etc/nginx/sites-enabled/
+```
+
+Test it's working:
+
+```sh
+nginx -t
+```
+
+## Troubleshooting
+
+If it's not working, the error message ends with the line number of the problem in the .conf file.
+If the error message says '4', the error message is probably around line 4.
+
+Check:
+
+- Missing semicolons
+- Very long website names
+   * Fixing this requires uncommenting `server_names_hash_bucket_size 64;` in /etc/nginx.conf
+   * If that doesn't work, try changing '64' in that line to '128'.
+
+## DNS
+
+Buy some DNS online, then check it's working.
+
+*Once it's working*, use certbot:
+
+```sh
+apt install certbot
+```
+
+You may need to install an nginx python module:
+
+```sh
+apt install python3-certbot-nginx
+```
+
+```sh
+domain=example.com
+my_email=me@posteo.uk
+certbot --nginx -d "$domain" --non-interactive --agree-tos -m "$my_email"
+```
+
+When you are asked about redirecting from HTTP to HTTPS, say yes (option "2").
+
+## Renewal
+
+Remember to renew the certificate every few months.
+
+# Multiple Sites
+
+You can do this with any number of websites at the same time.
+