feat: update Caddy config, add cache, improve response handling and logging

caddy/Caddyfile

@@ -1,10 +1,35 @@
-https://, ядро.орг, *.ядро.орг {
-	tls internal
+{
+    cache
+    log {
+        format console
+        level WARN
+    }
+}
+
+http://ядро.орг, http://*.ядро.орг {
+    tls internal
     encode gzip zstd
 
-    import Caddyfile.yadro localhost:8000
+    cache {
+        # we don't want to flood the upstream from the same IP
+        mode bypass
+        ttl 30m
+    }
+
+    import Caddyfile.yadro proxy:80
 }
 
-http://localhost:9000 {
-    import Caddyfile.puppies localhost:9001-9010
+:9000 {
+    reverse_proxy {
+        dynamic a puppy 80
+        lb_policy least_conn
+    }
+
+    cache {
+        allowed_http_verbs POST
+        ttl 7d
+        timeout {
+            backend 1m
+        }
+    }
 }

caddy/Caddyfile.puppies

@@ -1,6 +0,0 @@
-reverse_proxy {
-    to {args[0]}
-    lb_policy least_conn
-}
-
-# TODO: infinite cache by path+body

caddy/Dockerfile

@@ -0,0 +1,8 @@
+FROM caddy:builder AS builder
+
+RUN --mount=type=cache,target=/go/pkg/mod xcaddy build \
+    --with github.com/caddyserver/cache-handler
+
+FROM caddy:latest
+
+COPY --from=builder /usr/bin/caddy /usr/bin/caddy