docs for caddy example (#1939)

docs/content/examples/tutorials/caddy.md

@@ -2,8 +2,101 @@
 title: Caddy
 ---
 
-It seems like the Docs on how to setup Caddy are not available yet.
+/// note | Opinionated
 
-Feel free to create a PR and add them here.
+This guide is opinionated. If you use other conventions or folder layouts, feel free to change the commands and paths.
+///
 
-<!-- TODO -->
+We're using [Caddy](https://caddyserver.com/) here as reserve proxy to serve `wg-easy` on [https://wg-easy.example.com](https://wg-easy.example.com) via TLS.
+
+## Create a docker composition for `caddy`
+
+```txt
+.
+├── compose.yml
+└── Caddyfile
+
+1 directory, 2 files
+```
+
+```yaml
+# compose.yml
+
+services:
+    caddy:
+        container_name: caddy
+        image: caddy:2.10.0-alpine
+        # publish everything you deem necessary
+        ports:
+            - '80:80/tcp'
+            - '443:443/tcp'
+            - '443:443/udp'
+        networks:
+            - caddy
+        restart: unless-stopped
+        volumes:
+            - './Caddyfile:/etc/caddy/Caddyfile:ro'
+            - config:/config
+            - data:/data
+
+networks:
+    caddy:
+        name: caddy
+
+volumes:
+    config:
+    data:
+```
+
+```txt
+# Caddyfile
+
+{
+        # setup your email address
+        email mail@example.com
+}
+
+wg-easy.example.com {
+        # since the container will share the network with wg-easy
+        # we can use the proper container name
+        reverse_proxy wg-easy:80
+        tls internal
+}
+```
+
+...and start it with:
+
+```shell
+sudo docker-compose up -d
+```
+
+## Adapt the docker composition of `wg-easy`
+
+```yaml
+services:
+  wg-easy:
+    # sync container name and port according to Caddyfile
+    container_name: wg-easy
+    environment:
+      - PORT=80
+    # no need to publish the HTTP server anymore
+    ports:
+      - "51820:51820/udp"
+    # add to caddy network
+    networks:
+      caddy:
+    ...
+
+networks:
+  caddy:
+    external: true
+  ...
+```
+
+...and restart it with:
+
+```shell
+sudo docker-compose up -d
+```
+
+You can now access `wg-easy` at [https://wg-easy.example.com](https://wg-easy.example.com) and start the setup.