Add per-host reverse-proxy controls (rate limit, cache, headers, IP ACL)

Every proxied request flows through one shared OpenResty location whose
behavior is chosen at request time from the host's Redis hash. Add per-host
controls as new Host fields enforced in Lua rather than static nginx config
(which can't key off a per-request variable):

- Rate limiting: per-client-IP token bucket via resty.limit.req
  (ratelimit_enabled/rate/burst), backed by a new `ratelimit` shared dict.
- Response caching: opt-in per host via a global proxy_cache zone gated by
  $skip_cache (respcache_enabled). Off by default; upstream Cache-Control
  still honored.
- Custom/security headers: req_headers (upstream) + resp_headers (client) and
  hsts_enabled, applied in access/header_filter phases.
- IP allow/deny CIDR lists via resty.ipmatcher (deny wins; non-empty allow is
  default-deny).

New ops/nginx_conf/hostfeatures.lua holds the enforcement; proxy.conf's
access_by_lua string becomes a block that calls it, plus a header_filter block.
nodejs/utils/host_features.js is the pure, unit-tested normalize/validate layer
(header/CIDR parsing, range clamping, injection-safe values) applied in
routes/host.js and mirrored by the hosts.ejs edit form. install.sh gains the
ipmatcher rock, the cache dir, and the hostfeatures.lua symlink.

Per-host cache TTL is intentionally deferred (global default only) — see the
plan's limitations.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
2026-07-10 22:10:55 -04:00
parent e8f1ca56ec
commit 6092468901
11 changed files with 655 additions and 8 deletions
+10
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@@ -60,6 +60,15 @@ apt-get install -y nodejs openresty
echo "==> Lua modules"
luarocks install lua-resty-auto-ssl
luarocks install luasocket
# CIDR matcher for the per-host IP allow/deny lists (hostfeatures.lua).
# resty.limit.req is bundled with OpenResty, so no rock is needed for it.
luarocks install lua-resty-ipmatcher
echo "==> Proxy response-cache directory"
# Must be writable by the OpenResty worker user. nginx.conf sets no `user`
# directive, so workers run as the compiled-in default (nobody); own the dir to
# match so proxy_cache_path can write to it.
install -d -m 0755 -o nobody -g nogroup /var/cache/nginx/proxy
echo "==> Fallback SSL cert"
install -d /etc/ssl
@@ -91,6 +100,7 @@ link "$REPO_DIR/ops/nginx_conf/nginx.conf" /etc/openresty/nginx.conf
link "$REPO_DIR/ops/nginx_conf/autossl.conf" /etc/openresty/autossl.conf
link "$REPO_DIR/ops/nginx_conf/proxy.conf" /etc/openresty/sites-enabled/000-proxy
link "$REPO_DIR/ops/nginx_conf/targetinfo.lua" /usr/local/openresty/lualib/targetinfo.lua
link "$REPO_DIR/ops/nginx_conf/hostfeatures.lua" /usr/local/openresty/lualib/hostfeatures.lua
link "$REPO_DIR/ops/proxy.service" /etc/systemd/system/proxy.service
echo "==> Node dependencies"
+124
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@@ -0,0 +1,124 @@
-- Per-host reverse-proxy controls, enforced from the shared location's Lua
-- phases. The Host record (a Redis hash) is resolved by targetinfo.lua and
-- passed in here as `res`; targetinfo also stashes it in ngx.ctx.targetInfo so
-- the header-filter phase can re-read it.
--
-- Fields consumed (see nodejs/models/host.js):
-- ratelimit_enabled / ratelimit_rate / ratelimit_burst
-- respcache_enabled
-- hsts_enabled
-- req_headers (JSON object) -- added to the upstream request
-- resp_headers (JSON object) -- added to the client response
-- ip_allow / ip_deny (JSON arrays of CIDRs)
local cjson = require "cjson.safe"
local M = {}
-- cjson.safe returns nil (not an error) on bad input; treat non-tables as empty.
local function decode_table(str)
if not str or str == "" then return nil end
local ok = cjson.decode(str)
if type(ok) == "table" then return ok end
return nil
end
-- resty.ipmatcher wants a plain array of CIDR strings; build a matcher or nil.
local function build_matcher(str)
local list = decode_table(str)
if not list or #list == 0 then return nil end
local ipmatcher = require "resty.ipmatcher"
local m, err = ipmatcher.new(list)
if not m then
ngx.log(ngx.ERR, "hostfeatures: bad ip list ", err)
return nil
end
return m
end
-- IP allow/deny. deny wins; a non-empty allow list is default-deny.
local function apply_ip_access(res, ip)
local deny = build_matcher(res["ip_deny"])
if deny and deny:match(ip) then
return ngx.exit(403)
end
local allow = build_matcher(res["ip_allow"])
if allow and not allow:match(ip) then
return ngx.exit(403)
end
end
-- Per-host, per-client token bucket via lua-resty-limit-traffic (bundled with
-- OpenResty). Uses the shared dict "ratelimit" declared in nginx.conf.
local function apply_ratelimit(res, host, ip)
if res["ratelimit_enabled"] ~= "true" then return end
local rate = tonumber(res["ratelimit_rate"]) or 10
local burst = tonumber(res["ratelimit_burst"]) or 0
local limit_req = require "resty.limit.req"
local lim, err = limit_req.new("ratelimit", rate, burst)
if not lim then
-- Fail open on a misconfigured limiter rather than 500 every request.
ngx.log(ngx.ERR, "hostfeatures: failed to make limiter ", err)
return
end
local delay, derr = lim:incoming(host .. ":" .. ip, true)
if not delay then
if derr == "rejected" then
return ngx.exit(429)
end
ngx.log(ngx.ERR, "hostfeatures: limiter error ", derr)
return
end
if delay > 0 then
ngx.sleep(delay)
end
end
-- Extra request headers sent to the upstream.
local function apply_req_headers(res)
local headers = decode_table(res["req_headers"])
if not headers then return end
for name, value in pairs(headers) do
ngx.req.set_header(name, value)
end
end
-- access_by_lua entry point. Runs after targetinfo.get resolved `res`.
function M.access(ngx_, res)
if not res then return end
local ip = ngx.var.remote_addr
local host = ngx.var.host
apply_ip_access(res, ip)
apply_ratelimit(res, host, ip)
apply_req_headers(res)
-- Cache gate for proxy_no_cache / proxy_cache_bypass. Opt-in per host.
ngx.var.skip_cache = (res["respcache_enabled"] == "true") and "0" or "1"
end
-- header_filter_by_lua entry point. Reads the record stashed in ngx.ctx.
function M.header(ngx_)
local res = ngx.ctx.targetInfo
if not res then return end
local headers = decode_table(res["resp_headers"])
if headers then
for name, value in pairs(headers) do
ngx.header[name] = value
end
end
if res["hsts_enabled"] == "true" then
ngx.header["Strict-Transport-Security"] =
"max-age=31536000; includeSubDomains"
end
end
return M
+9
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@@ -18,6 +18,15 @@ http {
lua_shared_dict auto_ssl 100m;
lua_shared_dict auto_ssl_settings 64k;
# Per-host rate limiting (resty.limit.req) counter storage.
lua_shared_dict ratelimit 10m;
# Per-host response cache. Enabled per request via $skip_cache in proxy.conf;
# 10m is the default TTL when the upstream doesn't send its own Cache-Control.
proxy_cache_path /var/cache/nginx/proxy levels=1:2 keys_zone=proxycache:100m
max_size=2g inactive=60m use_temp_path=off;
proxy_cache_valid 200 301 302 10m;
resolver 8.8.4.4 8.8.8.8;
init_by_lua_block {
+22 -3
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@@ -18,9 +18,11 @@ server {
set $target_scheme 'http';
set $target_port '';
set $header_host $host;
set $skip_cache 1;
access_by_lua '
access_by_lua_block {
local targetInfo = require "targetinfo"
local hostfeatures = require "hostfeatures"
local host = ngx.var.host
local uri = ngx.var.uri
local scheme = ngx.var.scheme
@@ -39,16 +41,33 @@ server {
if res["host-pass-though"] == "false" then
ngx.var.header_host = res["ip"]
end
ngx.var.target = res["ip"]
ngx.var.target_port = res["targetPort"]
';
-- Per-host controls: IP allow/deny, rate limit, upstream headers, and
-- the $skip_cache gate. May ngx.exit() (403/429).
hostfeatures.access(ngx, res)
}
header_filter_by_lua_block {
require("hostfeatures").header(ngx)
}
resolver 192.168.1.1 ipv6=off; #8.8.4.4; # use Google's open DNS server
proxy_http_version 1.1;
proxy_pass_request_headers on;
# Response cache. Opt-in per host: $skip_cache is 0 only when the Host
# record sets respcache_enabled. Global default TTL lives in nginx.conf;
# upstream Cache-Control (private/no-store) is still honored.
proxy_cache proxycache;
proxy_cache_key $scheme$host$request_uri;
proxy_cache_bypass $skip_cache;
proxy_no_cache $skip_cache;
proxy_pass $target_scheme://$target:$target_port;
proxy_set_header Upgrade $http_upgrade;