scrabble-game/deploy/caddy/Caddyfile

# Edge reverse proxy for the Scrabble contour. A single Basic-Auth gate covers
# every operator surface under /_gm (the backend-rendered admin console and the
# Grafana subpath); the game SPA (/app/, /telegram/, /vk/) and the Connect edge go to
# the gateway; the catch-all — notably the public landing at / — goes to the
# static landing container, so stray traffic never reaches the Go edge.
# Mirrors ../galaxy-game's /_gm model.
#
# CADDY_SITE_ADDRESS is ":80" in the test contour (the host caddy terminates TLS
# and forwards); set it to a domain in prod so this caddy does its own
# ACME and the contour is self-contained.
{
	admin off
	# Trust X-Forwarded-For from private-range upstreams so the real client IP survives
	# (chat moderation + per-IP rate limiting in the gateway). Test contour: the host caddy
	# (a private IP) is trusted, so its forwarded client IP is preserved. Prod (no host caddy):
	# clients connect from public IPs, which are NOT trusted, so Caddy uses the real peer —
	# the same config is correct (and spoof-safe) in both contours.
	servers {
		trusted_proxies static private_ranges
	}
}

{$CADDY_SITE_ADDRESS::80} {
	# HTTP/3 is advertised by default whenever this caddy terminates TLS (prod:
	# CADDY_SITE_ADDRESS is the domain). But UDP/443 is never reachable — the prod
	# compose maps only "443:443" (TCP) and ufw opens 443/tcp — so a client that cached
	# the `Alt-Svc: h3` advert (sticky for ma=2592000s) stalls on the dead QUIC path
	# before falling back to h2, which surfaced as the Telegram Mini App intermittently
	# hanging on load. `Alt-Svc: clear` actively drops any cached alternative and pins
	# clients to h2/h1; it is applied site-wide so every route is covered. In the test
	# contour this caddy serves plain :80 (no h3 to advertise) and the host caddy
	# re-stamps its own Alt-Svc, so the live test fix lives in the host caddy — here it
	# is the prod fix. Background + alternatives (incl. serving h3 for real): docs/EDGE_HTTP3.md.
	header Alt-Svc clear

	# Maintenance gate. While the deploy holds the flag file /srv/maint/on (touched by
	# prod-deploy.sh around a rolling swap, removed on the script's exit), serve a static
	# 503 "works in progress" page instead of proxying to a mid-recreate upstream —
	# a graceful signal rather than raw 502s. Operator surfaces (/_gm) are excluded so
	# Grafana stays reachable during the window. Caddy stat()s the flag per request, so
	# toggling it needs no reload; the page + flag live in the caddy config dir bind-mounted
	# read-only at /srv/maint (docker-compose.yml). The test contour never sets the flag
	# (only prod-deploy.sh does), so this is inert there.
	@maintenance {
		not path /_gm /_gm/*
		file {
			root /srv/maint
			try_files on
		}
	}
	handle @maintenance {
		error 503
	}
	handle_errors {
		@maint503 expression {err.status_code} == 503
		handle @maint503 {
			root * /srv/maint
			rewrite * /maintenance.html
			header Retry-After 120
			# Distinctive maintenance marker so the SPA can tell a planned window apart from
			# a transient upstream 503 and show its own dimmed overlay (an in-session user
			# never sees this static page — it only renders on a fresh load). The header
			# rides every gated response, incl. the Connect/gRPC edge the app polls.
			header X-Scrabble-Maintenance 1
			file_server
		}
	}

	# Operator surfaces under /_gm: a single shared Basic-Auth, then route.
	@gm path /_gm /_gm/*
	handle @gm {
		basic_auth {
			{$GM_BASICAUTH_USER:gm} {$GM_BASICAUTH_HASH}
		}
		# Grafana serves from this sub-path (GF_SERVER_SERVE_FROM_SUB_PATH=true), so
		# the prefix is forwarded intact, not stripped.
		handle /_gm/grafana* {
			reverse_proxy grafana:3000
		}
		# Everything else under /_gm is the backend-rendered admin console.
		handle {
			reverse_proxy backend:8080
		}
	}

	# The game SPA and the Connect edge are served by the gateway. Strip any
	# client-supplied X-Scrabble-Honeypot here so the gateway only ever honours the
	# tag the honeypot block sets below (a client cannot self-tag a real request).
	@gateway path /app /app/* /telegram /telegram/* /vk /vk/* /dict/* /dl/* /metrics/* /scrabble.edge.v1.Gateway/*
	handle @gateway {
		reverse_proxy gateway:8081 {
			header_up -X-Scrabble-Honeypot
		}
	}

	# Honeypot decoy paths: classic vulnerability-scanner bait no real client ever
	# requests. Route them to the gateway tagged with X-Scrabble-Honeypot — the set
	# replaces any client-supplied value — so it logs the scanner hit and (in prod)
	# bans the source IP. (A delete + set in one block would not work: Caddy applies
	# header_up deletions after sets, which would strip the tag we just set; the real
	# endpoints instead strip the header in the @gateway block above.) Keep this list
	# disjoint from every legitimate landing/app path.
	@honeypot path /.env /.git /.git/* /.aws/* /wp-login.php /wp-admin /wp-admin/* /phpmyadmin /phpmyadmin/*
	handle @honeypot {
		reverse_proxy gateway:8081 {
			header_up X-Scrabble-Honeypot 1
		}
	}

	# Everything else — the public landing at / and any stray path — is static.
	handle {
		reverse_proxy landing:80
	}
}