self-host-101/caddy/readme.md

# Caddy web server and reverse proxy

Usually we will have multiple services and websites running on our VPS. So we need a web server which will listen on `HTTP` and `HTTPS` ports and redirect the traffic to correct service.

## Installation

I'll install caddy as a `systemd` service on my ubuntu machine. Hence I'll following [debian docs](https://caddyserver.com/docs/install#debian-ubuntu-raspbian) to install caddy.
To verify if caddy is installed and running run the following command.
```bash
sudo service caddy status
```
Caddy web server is now started on your VPS and you can visit `domain-name.com` and see the caddy homepage. Caddy homepage will tell you where to edit caddy config and where you can put your static files for your webserver.

## TLS Certificates

Right now Caddy is running on HTTP only `80` port. To use automatic HTTPS replace the `:80` port in caddy config to your domain name.
Before that ensure DNS record of domain name points to IP address of VPS.
```diff
- :80 {
+ domain-name.com {
}
```

After making any change to caddy config we also need to restart the caddy service.
```bash
sudo systemctl reload caddy
```
Now visit `domain-name.com` again and it will be serving site over HTTPS.
Caddy will automatically provision and renew TLS certificates from [LetsEncrypt](https://letsencrypt.org)

## Redirects

You might want to setup few redirects to your root domain for like IP Address and `www` sub domain.

```Caddyfile
192.168.1.1,
www.domain-name.com {
    redir https://domain-name.com{uri}
}
```
You can setup this rule for multiple domains by either writing them space seperated or comma seperated as above.
`{uri}` specified at the end of domain name preserves the path from the URL user entered.
Now if anyone visits your website via server's IP address or using `www` subdomain they will be redirected to your root domain.
**It just looks cleaner.**

## Multiple file caddy config

Caddy supports writing config in multiple files so that we don't polluting our main config. Just import all other caddy configs to the main caddy config.
Usually we can structure our config files in any way it doesn't matter. But there are some common ways to structure it.

Place all other config files inside `/etc/caddy/conf.d/` directory and import Caddyfile from this directory to main config file.
```Caddyfile
import conf.d/*.Caddyfile
```

## Handling errors

We can setup seperate error pages for different kind of error. But I'll be using single `error.html` page which is a [caddy template](https://caddyserver.com/docs/caddyfile/directives/templates) page and I can fill in error msg and error code using [placeholders](https://caddyserver.com/docs/modules/http.handlers.templates#placeholder).
For reference look at [error.html](./error.html) file.

To learn more about it check the Caddy docs **RTFM** about [handling errors](https://caddyserver.com/docs/caddyfile/directives/handle_errors).