Caddyfile

# Reverse proxy for local big-file testing that exercises the shared rendering
# process without requiring TLS.
#
# The shared rendering feature (HTTP2_SHARED_RENDERING_PROCESS_ENABLE) reuses a
# single pspdfkitd worker checkout across multiple tile requests that arrive as
# HTTP/2 streams on the same Cowboy connection. The worker is cached in the
# Cowboy connection process's dictionary, so multiplexing matters: requests on
# the same HTTP/2 connection share a worker, requests on separate connections
# do not.
#
# TLS is not needed for this to work. Caddy's h2c reverse_proxy uses Go's
# http.Transport, which maintains a pool of HTTP/2 connections to the upstream
# and multiplexes requests as streams onto them — regardless of whether the
# browser-to-Caddy leg is HTTP/1.1 or HTTP/2. Multiple browser HTTP/1.1
# requests are funnelled onto a single h2c upstream connection, giving Cowboy
# the HTTP/2 stream multiplexing it needs.
#
# Non-tile traffic (uploads, dashboard, API) stays on HTTP/1.1 upstream to
# avoid Cowboy's HTTP/2 reset-rate guard on large request bodies.
{
	auto_https off
}

:5000 {
	request_body {
		max_size 50GB
	}

	# Match the tile-rendering route that needs an upstream HTTP/2 hop to exercise the shared rendering process code path.
	@render_tiles path_regexp render_tiles ^/i/d/[^/]+/h/[^/]+/page-.*

	handle @render_tiles {
		reverse_proxy h2c://document-engine:5000
	}

	handle {
		reverse_proxy http://document-engine:5000 {
			transport http {
				versions 1.1
				response_header_timeout 15m
			}
		}
	}
}