# chess-io — reverse proxy for davidwindham.com/chess
# ============================================================================
#
# The chess app is a long-running Node process (see chess-io.service.example).
# It is NOT served from the web docroot like the PHP/WordPress parts of the
# site — Apache proxies /chess through to node on 127.0.0.1:8181.
#
# Add the block below to the EXISTING davidwindham.com <VirtualHost> (the same
# one that serves WordPress). Do NOT create a new vhost for it — /chess has to
# live under the main hostname so it is same-origin with the rest of the site;
# that is what lets the client open its websocket with no hardcoded host and
# keeps it from tripping mixed-content blocking on https.
#
# This REPLACES the old chess.davidwindham.com subdomain vhost, which
# root-mounted the app ("ProxyPass / http://127.0.0.1:8181/") on its own
# hostname. Two differences now that it's a subpath:
#   - socket.io lives at /chess/socket.io, not /socket.io
#   - the /chess prefix is KEPT on the way to node (BASE_PATH=/chess), where the
#     old root mount had nothing to keep.
#
# ---------------------------------------------------------------------------
# Which option? Check your Apache version first:
#     apache2 -v      (or: apachectl -v  /  httpd -v)
# ---------------------------------------------------------------------------
#
# >= 2.4.47  ->  Option A. One line carries both HTTP and the websocket.
# <  2.4.47  ->  Option B. ProxyPass for HTTP + a mod_rewrite rule for the
#                websocket upgrade (the same technique the old subdomain vhost
#                used, adapted to the /chess subpath).
#
# Use ONE option, not both. Modules needed either way:
#     a2enmod proxy proxy_http rewrite
# Option A additionally: nothing. Option B additionally: proxy_wstunnel.
#
# The node app must be running with BASE_PATH=/chess and TRUST_PROXY=1 — see
# chess-io.service.example.

# ===========================================================================
# OPTION A — Apache 2.4.47+  (preferred)
# ===========================================================================
# Paste inside <VirtualHost *:443> for davidwindham.com.

    ProxyPreserveHost On

    # chess: real-time chess on node, mounted at /chess.
    # Prefix kept on both sides; BASE_PATH=/chess tells the app to expect it.
    # upgrade=websocket carries socket.io at /chess/socket.io (needs 2.4.47+).
    ProxyPass         /chess  http://127.0.0.1:8181/chess  upgrade=websocket
    ProxyPassReverse  /chess  http://127.0.0.1:8181/chess


# ===========================================================================
# OPTION B — Apache < 2.4.47  (mod_rewrite fallback)
# ===========================================================================
# Use this INSTEAD of Option A if your Apache predates upgrade=websocket
# (e.g. Ubuntu 20.04 ships 2.4.41, Debian 10 ships 2.4.38).
#
# The RewriteRule must appear before the ProxyPass. The two RewriteConds gate
# it to genuine websocket-upgrade requests only; everything else — page loads,
# static assets, socket.io's HTTP long-polling — falls through to ProxyPass.
#
# This matches on the Upgrade/Connection headers, which is more robust than the
# old "?transport=websocket" query-string test but does the same job. If you
# prefer to mirror the old vhost exactly, the query-string form also works:
#     RewriteCond %{REQUEST_URI}  ^/chess/socket.io  [NC]
#     RewriteCond %{QUERY_STRING} transport=websocket [NC]
#     RewriteRule /(.*) ws://127.0.0.1:8181/$1 [P,L]

    ProxyPreserveHost On

    RewriteEngine On
    RewriteCond %{HTTP:Upgrade}    =websocket [NC]
    RewriteCond %{HTTP:Connection} upgrade    [NC]
    RewriteRule ^/chess/(.*) ws://127.0.0.1:8181/chess/$1 [P,L]

    ProxyPass         /chess  http://127.0.0.1:8181/chess
    ProxyPassReverse  /chess  http://127.0.0.1:8181/chess

# ---------------------------------------------------------------------------
# Notes
# ---------------------------------------------------------------------------
#
# * /embed/chrome.js (the shared header/footer) is served by Apache from the
#   WordPress docroot, NOT by this app. Nothing to configure here for it — the
#   page loads it root-relative and it already resolves alongside /chess.
#   DAW_ORIGIN is a LOCAL-DEV-ONLY shim and must stay UNSET in production.
#
# * No trailing-slash rule is needed in Apache: the app itself 301s /chess to
#   /chess/ so relative asset URLs resolve.
#
# * Optional, from the old vhost: it served a friendly 503 page when node was
#   down ("ProxyPass /error/ !" + "ErrorDocument 503 /error/503.html"). Under
#   the main site vhost that's optional — WordPress's own error handling covers
#   it — but you can keep the pattern if you want a chess-specific down page.
#
# * Point the old chess.davidwindham.com subdomain at a redirect to
#   https://davidwindham.com/chess/ once this is confirmed working, so old game
#   links don't dead-end:
#       <VirtualHost *:80>
#         ServerName chess.davidwindham.com
#         ServerAlias www.chess.davidwindham.com
#         Redirect permanent / https://davidwindham.com/chess/
#       </VirtualHost>