Add ddns caddy module

Dockerfile.caddy

@@ -0,0 +1,9 @@
+FROM caddy:2-builder AS builder
+
+RUN xcaddy build \
+  --with github.com/caddy-dns/cloudflare \
+  --with github.com/mholt/caddy-dynamicdns
+
+FROM caddy:2
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy

docker-compose.yml

@@ -1,6 +1,7 @@
 services:
   caddy:
-    image: caddy:2
+    build:
+      dockerfile: Dockerfile.caddy
     container_name: caddy
     restart: unless-stopped
     cap_add:
@@ -13,6 +14,8 @@ services:
       - /tank/git/homelab-config/caddy:/etc/caddy
       - /tank/services/caddy/data:/data
       - /tank/services/caddy/config:/config
+    environment:
+      - CLOUDFLARE_API_KEY=${CLOUDFLARE_API_KEY?}
 
   tsdproxy:
     image: almeidapaulopt/tsdproxy:1