PluginProbe
xSpeed Cache: AI-Powered Performance Hub with MCP, Caching & CDN / 1.3.7
xSpeed Cache: AI-Powered Performance Hub with MCP, Caching & CDN v1.3.7
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← All changes | includes/class-server.php +649 -39 1.0.2 → 1.3.7 View file →
@@ -21,8 +21,16 @@
21 21 const UNKNOWN = 'unknown';
22 22
23 23 const OPT_CACHED_TYPE = 'xspeed_server_type';
24 24
25 + /**
26 + * Last authoritative mod_headers answer, captured under mod_php where
27 + * apache_get_modules() actually exists. Read by SAPIs that cannot
28 + * detect (WP-CLI, FPM) so one host gives one answer. See
29 + * apache_has_mod_headers().
30 + */
31 + const OPT_CACHED_MOD_HEADERS = 'xspeed_apache_mod_headers';
32 +
25 33 public static function type() {
26 34 $detected = self::detect();
27 35 if ( self::UNKNOWN !== $detected ) {
28 36 // Persist whenever we have a real answer so future CLI /
@@ -31,20 +39,36 @@
31 39 $cached = get_option( self::OPT_CACHED_TYPE, null );
32 40 if ( $cached !== $detected ) {
33 41 update_option( self::OPT_CACHED_TYPE, $detected, false );
34 42 }
35 - return $detected;
43 + $type = $detected;
44 + } else {
45 + // No definitive signal this request (typically WP-CLI, where
46 + // SERVER_SOFTWARE is empty). Read whatever was cached the last
47 + // time we ran from a real HTTP request.
48 + $cached = get_option( self::OPT_CACHED_TYPE, null );
49 + $type = ( is_string( $cached ) && '' !== $cached ) ? $cached : self::UNKNOWN;
36 50 }
37 51
38 - // No definitive signal this request (typically WP-CLI, where
39 - // SERVER_SOFTWARE is empty). Read whatever was cached the last
40 - // time we ran from a real HTTP request.
41 - $cached = get_option( self::OPT_CACHED_TYPE, null );
42 - if ( is_string( $cached ) && '' !== $cached ) {
43 - return $cached;
44 - }
45 -
46 - return self::UNKNOWN;
52 + /**
53 + * Filters the resolved server type.
54 + *
55 + * The override point for contexts that cannot detect. Detection
56 + * reads SERVER_SOFTWARE, which the web server supplies and WP-CLI
57 + * therefore never has; the cached option covers CLI runs on a site
58 + * some request has already reached, but a site provisioned entirely
59 + * over WP-CLI has nothing cached and resolves to `unknown` even on
60 + * nginx. `wp xspeed cache nginx-config --server=` hooks this so
61 + * every gate downstream — Cache::nginx_snippet(), each module's own
62 + * nginx_directives() — agrees on one answer, rather than each
63 + * re-deciding and emitting a half-built config.
64 + *
65 + * Filtering does NOT write the cached option: an assumption stated
66 + * for one command must not become this site's persisted answer.
67 + *
68 + * @param string $type One of apache|litespeed|nginx|iis|unknown.
69 + */
70 + return apply_filters( 'xspeed_server_type', $type );
47 71 }
48 72
49 73 /**
50 74 * Live detection — never reads the cache. Used by type() and by
@@ -89,8 +113,203 @@
89 113 return self::APACHE === $t || self::LITESPEED === $t;
90 114 }
91 115
92 116 /**
117 + * Whether Apache can stamp a response header from `.htaccess`
118 + * (i.e. mod_headers is loaded).
119 + *
120 + * This decides whether the static-rewrite fast path can be used at
121 + * all. A statically-served file bypasses PHP entirely, so the ONLY
122 + * way to mark it as a cache HIT is a `Header` directive in the
123 + * rewrite block. Without mod_headers that directive is silently
124 + * swallowed by its `<IfModule>` guard, and the site serves fast but
125 + * completely invisible cache hits — no `X-XSpeed-Cache` header for
126 + * the user, nothing for the hit counter. That is exactly the
127 + * "cache works, dashboard says 0%" report this check exists to
128 + * prevent. (Cache::static_rewrite_allowed() consumes it.)
129 + *
130 + * Detection is best-effort by necessity, and MUST NOT vary by SAPI:
131 + * - mod_php exposes apache_get_modules() — authoritative. Persist
132 + * that answer so other SAPIs can inherit it.
133 + * - Under PHP-FPM / WP-CLI the function doesn't exist. Read the
134 + * stored mod_php answer; only when nothing was ever stored do we
135 + * assume the module IS present, matching Apache's own default
136 + * build (mod_headers ships enabled in every mainstream distro
137 + * package). Guessing "absent" there would push every FPM site
138 + * onto the slower drop-in path over a detection limitation
139 + * rather than a real capability gap; the loopback probe in
140 + * Cache::probe_static_rewrite() is what catches a genuinely
141 + * header-less FPM host.
142 + *
143 + * Returning a different answer per SAPI is not merely inaccurate: it
144 + * makes static_rewrite_allowed() disagree with the on-disk .htaccess,
145 + * so every WP-CLI bootstrap "corrects" what the last web request
146 + * wrote and vice versa — an endless rewrite/purge ping-pong that
147 + * keeps the hit ratio pinned near zero. (#138)
148 + *
149 + * @return bool
150 + */
151 + public static function apache_has_mod_headers(): bool {
152 + if ( function_exists( 'apache_get_modules' ) ) {
153 + $has = in_array( 'mod_headers', apache_get_modules(), true );
154 +
155 + // Authoritative — persist so CLI/FPM inherit it instead of
156 + // guessing. Non-autoloaded; only read when needed.
157 + $cached = get_option( self::OPT_CACHED_MOD_HEADERS, null );
158 + $want = $has ? '1' : '0';
159 + if ( (string) $cached !== $want ) {
160 + update_option( self::OPT_CACHED_MOD_HEADERS, $want, false );
161 + }
162 + } else {
163 + // Cannot detect here. Prefer the last known real answer over
164 + // an optimistic guess that would flip static_rewrite_allowed().
165 + $cached = get_option( self::OPT_CACHED_MOD_HEADERS, null );
166 + $has = ( null === $cached || '' === $cached )
167 + ? true // never detected: assume the distro default.
168 + : (bool) (int) $cached;
169 + }
170 +
171 + /**
172 + * Filter: xspeed_apache_has_mod_headers
173 + *
174 + * Override mod_headers detection. Return false on a host where
175 + * `.htaccess` Header directives are stripped (some managed
176 + * stacks do this) to force cache hits through the PHP drop-in,
177 + * where they are stamped and counted.
178 + *
179 + * @param bool $has Whether mod_headers appears to be available.
180 + */
181 + return (bool) apply_filters( 'xspeed_apache_has_mod_headers', $has );
182 + }
183 +
184 + /**
185 + * Accept a candidate access-log path only if it can actually be
186 + * tail-scanned, else ''.
187 + *
188 + * `is_readable()` alone is not enough. The official WordPress and
189 + * Apache Docker images symlink `access.log -> /dev/stdout`, i.e. a
190 + * PIPE: `is_file()` is false, `filesize()` is 0, and `is_readable()`
191 + * is false for the PHP user. Hit_Counter::collect_server_log_hits()
192 + * fseek()s to a stored byte offset and reads forward, which a pipe
193 + * or character device cannot support at all — it would either fail
194 + * or block. Requiring a REGULAR file makes that contract explicit
195 + * instead of relying on the filesize>0 test to reject pipes as a
196 + * side effect. Containerised Apache is the standard layout, not an
197 + * edge case, so this path is common. (Field report: hit ratio stuck
198 + * at 0% on Dockerised Apache while the cache served correctly.)
199 + *
200 + * @param string $path Candidate path.
201 + * @return string The path when usable, '' otherwise.
202 + */
203 + private static function usable_access_log( string $path ): string {
204 + if ( '' === $path ) {
205 + return '';
206 + }
207 + // is_file() resolves symlinks, so access.log -> /var/log/real.log
208 + // is still accepted; only the pipe/device targets are rejected.
209 + if ( ! @is_file( $path ) || ! is_readable( $path ) ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- racey stat on an external log; treated as "unusable".
210 + return '';
211 + }
212 + return $path;
213 + }
214 +
215 + /**
216 + * Best-effort path to the web server's access log, used to count
217 + * static-rewrite HITs that bypass PHP on Apache/LiteSpeed (those
218 + * requests are served straight from disk and never reach our
219 + * Hit_Counter inline — see Hit_Counter::collect_server_log_hits()).
220 + *
221 + * Resolution order:
222 + * 1. The `XSPEED_ACCESS_LOG` constant, if defined (explicit override
223 + * for hosts where the log lives somewhere non-standard).
224 + * 2. The `xspeed_access_log_path` filter (programmatic override).
225 + * 3. Auto-detection: a short list of the standard Apache/LiteSpeed
226 + * access-log locations, returning the first that exists AND is
227 + * readable by the PHP user.
228 + *
229 + * Every route is funnelled through usable_access_log(), so an
230 + * override can no more hand us a pipe than auto-detection can.
231 + *
232 + * Returns '' when nothing usable is found — a very common case on
233 + * managed/cPanel hosts where the PHP user can't read the server log,
234 + * and on containers where it's a symlink to stdout. Callers MUST
235 + * treat '' as "can't count static hits here" and fall back
236 + * gracefully (the drop-in path still counts its own HITs).
237 + *
238 + * @return string Absolute path, or '' if none is usable.
239 + */
240 + public static function access_log_path(): string {
241 + if ( defined( 'XSPEED_ACCESS_LOG' ) && is_string( XSPEED_ACCESS_LOG ) && '' !== XSPEED_ACCESS_LOG ) {
242 + return self::usable_access_log( XSPEED_ACCESS_LOG );
243 + }
244 +
245 + /**
246 + * Filter: xspeed_access_log_path
247 + *
248 + * Override the auto-detected access-log path. Return '' to disable
249 + * server-log hit counting entirely.
250 + *
251 + * @param string|null $path Null = use auto-detection below.
252 + */
253 + $filtered = apply_filters( 'xspeed_access_log_path', null );
254 + if ( is_string( $filtered ) ) {
255 + return self::usable_access_log( $filtered );
256 + }
257 +
258 + // Auto-detect: the standard Apache + OpenLiteSpeed/LiteSpeed
259 + // Enterprise access-log locations. First readable, NON-EMPTY file
260 + // wins — an empty global access.log (common on LiteSpeed, which
261 + // logs per-vhost instead) must not shadow the real per-vhost log we
262 + // discover below.
263 + $candidates = array(
264 + '/var/log/apache2/access.log', // Debian/Ubuntu Apache
265 + '/var/log/httpd/access_log', // RHEL/CentOS Apache
266 + '/var/log/apache2/other_vhosts_access.log', // Debian multi-vhost
267 + '/usr/local/lsws/logs/access.log', // OpenLiteSpeed global
268 + '/var/log/lshttpd/access.log', // LiteSpeed Enterprise
269 + );
270 + foreach ( $candidates as $path ) {
271 + // usable_access_log() enforces "regular file + readable"; the
272 + // non-empty test stays here so an empty global log doesn't
273 + // shadow the real per-vhost one found further below.
274 + if ( '' !== self::usable_access_log( $path ) && (int) @filesize( $path ) > 0 ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- racey stat, treated as "skip".
275 + return $path;
276 + }
277 + }
278 +
279 + // LiteSpeed (and some Apache vhost setups) write a per-vhost
280 + // `<vhost>.access.log` rather than a single global file. Scan the
281 + // known log dirs for the most-recently-written, readable, non-empty
282 + // *.access.log and use that. Auto-tracks whichever vhost is serving
283 + // this site without the admin having to set a path.
284 + $dirs = array( '/usr/local/lsws/logs', '/var/log/lshttpd', '/var/log/apache2', '/var/log/httpd' );
285 + $best = '';
286 + $best_mtime = 0;
287 + foreach ( $dirs as $dir ) {
288 + if ( ! is_dir( $dir ) ) {
289 + continue;
290 + }
291 + $globbed = glob( $dir . '/*access*log*' );
292 + if ( ! is_array( $globbed ) ) {
293 + continue;
294 + }
295 + foreach ( $globbed as $path ) {
296 + // Same regular-file contract as the fixed candidates: a
297 + // glob can just as easily turn up a symlink to stdout.
298 + if ( '' === self::usable_access_log( $path ) || (int) @filesize( $path ) === 0 ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
299 + continue;
300 + }
301 + $mtime = (int) @filemtime( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
302 + if ( $mtime > $best_mtime ) {
303 + $best_mtime = $mtime;
304 + $best = $path;
305 + }
306 + }
307 + }
308 + return $best;
309 + }
310 +
311 + /**
93 312 * GZIP support category for the UI:
94 313 * 'auto' — toggling writes server config (Apache / LiteSpeed)
95 314 * 'manual' — must be configured outside the plugin (nginx, IIS, unknown)
96 315 */
@@ -97,8 +316,359 @@
97 316 public static function gzip_mode() {
98 317 return self::supports_htaccess() ? 'auto' : 'manual';
99 318 }
100 319
320 + /**
321 + * Whether the server can serve Brotli-compressed responses.
322 + *
323 + * Brotli is an optional server module (mod_brotli on Apache,
324 + * ngx_brotli on nginx, built in on LiteSpeed/OpenLiteSpeed) — unlike
325 + * GZIP it is NOT guaranteed present. We report availability so the UI
326 + * and any add-on (xspeed-pro Brotli module) can decide whether to
327 + * emit Brotli rules or fall back to GZIP only.
328 + *
329 + * Detection, cheapest signal first:
330 + * 1. LiteSpeed — Brotli is part of the core server, always available.
331 + * 2. Apache mod_php — apache_get_modules() lists 'mod_brotli'.
332 + * 3. PHP `brotli` extension (kjdev/php-ext-brotli) — lets us at least
333 + * pre-compress static files even when the web server can't.
334 + * Anything else (nginx/FPM, IIS, unknown) is reported as not detected;
335 + * the user can still wire ngx_brotli manually and the UI surfaces a
336 + * snippet, mirroring how GZIP behaves on nginx.
337 + *
338 + * Result is filterable so a host with a known-good but undetectable
339 + * setup (e.g. nginx + ngx_brotli) can force-enable.
340 + */
341 + public static function brotli_available(): bool {
342 + $available = false;
343 +
344 + if ( self::LITESPEED === self::type() ) {
345 + $available = true;
346 + } elseif ( function_exists( 'apache_get_modules' ) && in_array( 'mod_brotli', apache_get_modules(), true ) ) {
347 + $available = true;
348 + } elseif ( function_exists( 'brotli_compress' ) ) {
349 + $available = true;
350 + } elseif ( self::NGINX === self::type() ) {
351 + // nginx modules are not introspectable from PHP, so none of the
352 + // branches above can ever be true on the very common nginx +
353 + // php-fpm setup — even while ngx_brotli is actively serving
354 + // `Content-Encoding: br` on every request. Reporting "unavailable"
355 + // there told users who had done everything right to go install a
356 + // module they already had.
357 + //
358 + // So ask the server instead of asking PHP: one cached loopback
359 + // request with `Accept-Encoding: br`, and read what comes back.
360 + $available = self::brotli_probe();
361 + }
362 +
363 + /**
364 + * Filter detected Brotli availability.
365 + *
366 + * @param bool $available Whether Brotli serving was detected.
367 + */
368 + return (bool) apply_filters( 'xspeed_brotli_available', $available );
369 + }
370 +
371 + /**
372 + * Ask the web server whether it serves Brotli, by requesting our own home
373 + * URL with `Accept-Encoding: br` and reading the response encoding.
374 + *
375 + * The only way to answer this on nginx: the module list isn't visible to
376 + * PHP, so introspection can't work and the request itself is the evidence.
377 + *
378 + * Cached in a transient — a positive result for a day (server modules
379 + * don't come and go), a negative for an hour so someone who has just
380 + * installed ngx_brotli isn't told "no" until tomorrow. Failures cache
381 + * briefly too, so a host that hangs on loopback self-requests can't turn
382 + * every dashboard load into a timeout.
383 + *
384 + * @param bool $force Skip the cache and re-probe.
385 + */
386 + public static function brotli_probe( bool $force = false ): bool {
387 + return 'yes' === self::brotli_probe_state( $force );
388 + }
389 +
390 + /**
391 + * The probe's three-way answer: 'yes', 'no', or 'unknown'.
392 + *
393 + * brotli_probe() collapses this to a bool because every consumer wants
394 + * one, but the distinction matters for what we TELL the user.
395 + * "unknown" — a blocked or failing loopback — is not evidence that the
396 + * server lacks Brotli, and reporting it as "no" would repeat the original
397 + * bug in a new place: telling someone whose setup is fine that it isn't.
398 + *
399 + * @param bool $force Skip the cache and re-probe.
400 + * @return string 'yes' | 'no' | 'unknown'
401 + */
402 + public static function brotli_probe_state( bool $force = false ): string {
403 + $key = 'xspeed_brotli_probe';
404 +
405 + if ( ! $force ) {
406 + $cached = get_transient( $key );
407 + if ( false !== $cached ) {
408 + $cached = (string) $cached;
409 + // Legacy '1'/'0' values from an earlier cache format.
410 + if ( '1' === $cached ) {
411 + return 'yes';
412 + }
413 + if ( '0' === $cached ) {
414 + return 'no';
415 + }
416 + return in_array( $cached, array( 'yes', 'no', 'unknown' ), true ) ? $cached : 'unknown';
417 + }
418 + }
419 +
420 + $url = home_url( '/' );
421 + if ( ! function_exists( 'wp_remote_get' ) || '' === $url ) {
422 + return 'unknown';
423 + }
424 +
425 + // Stampede guard. On a cold transient every concurrent dashboard load
426 + // would otherwise fire its own 3s loopback request, because nothing
427 + // was written until the response came back. Claim the slot BEFORE the
428 + // request so the other callers answer 'unknown' (accurate — they
429 + // genuinely don't know yet) rather than piling on.
430 + $inflight = $key . '_inflight';
431 + if ( ! $force && false !== get_transient( $inflight ) ) {
432 + return 'unknown';
433 + }
434 + set_transient( $inflight, 1, 30 );
435 +
436 + // Mirror Cache::probe_static_rewrite()'s posture: short timeout so a
437 + // blocked loopback can't stall the caller, and relax cert verification
438 + // only in local/dev where self-signed certs are normal.
439 + $is_local = function_exists( 'wp_get_environment_type' )
440 + && in_array( wp_get_environment_type(), array( 'local', 'development' ), true );
441 +
442 + $resp = wp_remote_get(
443 + $url,
444 + array(
445 + 'timeout' => 3,
446 + 'sslverify' => ! $is_local,
447 + 'redirection' => 0,
448 + 'headers' => Self_Traffic::headers(
449 + array(
450 + // `br` ONLY. Offering gzip as well would let a server that
451 + // prefers gzip answer with it and look like a brotli
452 + // failure, which is exactly the false negative this method
453 + // exists to remove.
454 + 'Accept-Encoding' => 'br',
455 + 'Cache-Control' => 'no-cache',
456 + )
457 + ),
458 + )
459 + );
460 +
461 + delete_transient( $inflight );
462 +
463 + if ( is_wp_error( $resp ) ) {
464 + // Can't reach ourselves. This is NOT evidence the server lacks
465 + // Brotli — reporting it as "no" would repeat the original bug in a
466 + // new place. Cache briefly so a hanging host doesn't cost 3s on
467 + // every call, but re-check soon.
468 + set_transient( $key, 'unknown', 5 * MINUTE_IN_SECONDS );
469 + return 'unknown';
470 + }
471 +
472 + // A non-2xx answer tells us nothing about compression: basic auth
473 + // (401), maintenance mode (503) and WAF challenge pages are all
474 + // "couldn't check", not "no module". Caching 'no' for an hour on the
475 + // strength of one is the same category error this method fixes.
476 + $code = (int) wp_remote_retrieve_response_code( $resp );
477 + if ( $code < 200 || $code >= 300 ) {
478 + set_transient( $key, 'unknown', 5 * MINUTE_IN_SECONDS );
479 + return 'unknown';
480 + }
481 +
482 + // A CDN or reverse proxy in front of the origin compresses on its own
483 + // behalf, so `content-encoding: br` would describe the EDGE, not this
484 + // server. On Apache/LiteSpeed that is harmless (brotli_available()
485 + // short-circuits before consulting the probe), but on nginx the probe
486 + // IS the answer — and a large share of nginx sites sit behind
487 + // Cloudflare, Fastly or a load balancer. Asserting 'yes' there is the
488 + // mirror image of the false negative this method exists to remove, so
489 + // we answer 'unknown': we genuinely could not observe the origin.
490 + if ( self::response_came_through_proxy( $resp ) ) {
491 + set_transient( $key, 'unknown', HOUR_IN_SECONDS );
492 + return 'unknown';
493 + }
494 +
495 + $encoding = wp_remote_retrieve_header( $resp, 'content-encoding' );
496 + if ( is_array( $encoding ) ) {
497 + $encoding = implode( ',', $encoding );
498 + }
499 + $serves_brotli = false !== stripos( (string) $encoding, 'br' );
500 +
501 + // A positive is durable (server modules don't come and go); a negative
502 + // expires sooner so someone who has just installed ngx_brotli isn't
503 + // told "no" until tomorrow.
504 + $state = $serves_brotli ? 'yes' : 'no';
505 + set_transient( $key, $state, $serves_brotli ? DAY_IN_SECONDS : HOUR_IN_SECONDS );
506 +
507 + return $state;
508 + }
509 +
510 + /**
511 + * Did this response come back through a CDN / reverse proxy rather than
512 + * straight from our own web server?
513 + *
514 + * home_url() resolves through public DNS, so the request can leave the
515 + * box entirely and be answered at an edge. These headers are the evidence
516 + * the edge leaves behind; none of them are set by a plain origin.
517 + *
518 + * Deliberately conservative — a false "there's a proxy" costs a user the
519 + * capability assertion and shows the 'unknown' copy, while a false "no
520 + * proxy" tells an nginx user Brotli is on when their origin cannot serve
521 + * it. Cache::probe_static_rewrite() shares this blind spot, which is why
522 + * this is a public helper rather than inline.
523 + *
524 + * @param array|\WP_Error $resp Response from wp_remote_get().
525 + */
526 + public static function response_came_through_proxy( $resp ): bool {
527 + if ( is_wp_error( $resp ) ) {
528 + return false;
529 + }
530 +
531 + // Headers whose mere presence means an intermediary handled this.
532 + foreach ( array( 'cf-ray', 'x-served-by', 'x-cache', 'via', 'x-varnish', 'fastly-io-info', 'x-amz-cf-id', 'x-akamai-transformed', 'x-sucuri-id' ) as $header ) {
533 + $value = wp_remote_retrieve_header( $resp, $header );
534 + if ( is_array( $value ) ) {
535 + $value = implode( ',', $value );
536 + }
537 + if ( '' !== (string) $value ) {
538 + return true;
539 + }
540 + }
541 +
542 + // `server:` naming a known edge. Checked by substring because these
543 + // arrive as `cloudflare`, `Sucuri/Cloudproxy`, `AkamaiGHost`, etc.
544 + $server = wp_remote_retrieve_header( $resp, 'server' );
545 + if ( is_array( $server ) ) {
546 + $server = implode( ',', $server );
547 + }
548 + $server = strtolower( (string) $server );
549 + foreach ( array( 'cloudflare', 'cloudfront', 'akamai', 'fastly', 'sucuri', 'incapsula', 'stackpath', 'bunnycdn', 'keycdn' ) as $needle ) {
550 + if ( false !== strpos( $server, $needle ) ) {
551 + return true;
552 + }
553 + }
554 +
555 + return (bool) apply_filters( 'xspeed_response_came_through_proxy', false, $resp );
556 + }
557 +
558 + /**
559 + * Drop the cached Brotli probe result so the next call re-checks.
560 + *
561 + * Without this a user who installs ngx_brotli has no way to make the
562 + * dashboard notice before the transient expires — the same gap
563 + * Cache::recheck_static_rewrite() exists to close.
564 + */
565 + public static function recheck_brotli(): bool {
566 + delete_transient( 'xspeed_brotli_probe' );
567 + return self::brotli_probe( true );
568 + }
569 +
570 + /**
571 + * Is WordPress running inside a container (Docker / Podman / k8s)?
572 + *
573 + * Three signals checked in cheapness order, OR'd together:
574 + * 1. /.dockerenv exists — Docker's traditional marker; rare absence.
575 + * 2. /proc/self/mountinfo references /var/lib/docker/overlay2 or
576 + * containerd/podman storage drivers — works under cgroup v2.
577 + * 3. /proc/1/cgroup names docker / kubepods / containerd / podman / lxc
578 + * — the cgroup v1 signal, still present on older Docker installs.
579 + *
580 + * Any single positive returns true. On non-Linux hosts (Windows /
581 + * macOS / WSL host process), all three quietly return false and we
582 + * fall back to "not containerized."
583 + */
584 + public static function is_containerized(): bool {
585 + // 1. Docker marker file — cheap to stat, almost always present.
586 + if ( file_exists( '/.dockerenv' ) ) {
587 + return true;
588 + }
589 + // 2. mountinfo overlay2 / containerd footprint — works under cgroup v2.
590 + // Gate on is_readable() first: on non-Linux hosts (macOS/Windows) or
591 + // hosts that hide /proc (open_basedir, hardened Apache), the file is
592 + // absent and reading it would emit a warning. Query Monitor surfaces
593 + // even @-suppressed warnings, so guard rather than silence. (FBS-83114)
594 + if ( is_readable( '/proc/self/mountinfo' ) ) {
595 + // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- /proc/self/mountinfo is a virtual file; WP_Filesystem doesn't model /proc.
596 + $mounts = file_get_contents( '/proc/self/mountinfo' );
597 + if ( is_string( $mounts ) && '' !== $mounts && preg_match( '#(docker/overlay2|/var/lib/containerd|/var/lib/podman)#i', $mounts ) ) {
598 + return true;
599 + }
600 + }
601 + // 3. cgroup v1 fallback.
602 + if ( is_readable( '/proc/1/cgroup' ) ) {
603 + // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- See above.
604 + $cgroup = file_get_contents( '/proc/1/cgroup' );
605 + if ( is_string( $cgroup ) && '' !== $cgroup && preg_match( '#(docker|kubepods|containerd|podman|lxc)#i', $cgroup ) ) {
606 + return true;
607 + }
608 + }
609 + return false;
610 + }
611 +
612 + /**
613 + * Is WordPress likely behind a reverse proxy (host nginx → container
614 + * php-fpm, host nginx → docker nginx, etc.)? Detection is a heuristic
615 + * built from the headers WordPress hands to PHP: when a proxy forwards
616 + * the request it almost always sets X-Forwarded-* or X-Real-IP.
617 + *
618 + * False positives (CDN-only forwarding without a local reverse proxy)
619 + * are acceptable — the caller uses this signal only to soften messaging
620 + * that would otherwise mislead container-host customers. False negatives
621 + * (proxy that strips headers) just mean we keep showing the snippet
622 + * paste UX, which is the safe default.
623 + */
624 + public static function is_behind_proxy(): bool {
625 + $proxy_headers = array( 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED_HOST', 'HTTP_X_FORWARDED_PROTO', 'HTTP_X_REAL_IP', 'HTTP_X_FORWARDED_SERVER' );
626 + foreach ( $proxy_headers as $h ) {
627 + if ( ! empty( $_SERVER[ $h ] ) ) {
628 + return true;
629 + }
630 + }
631 + return false;
632 + }
633 +
634 + /**
635 + * High-level topology classifier driving the rewrite-alert UX.
636 + *
637 + * Decides WHERE the user's nginx snippet needs to be installed
638 + * (or whether automatic install via .htaccess covers it). The
639 + * dashboard banner uses the return value to render the right
640 + * "paste this here" message — there is no topology that can't
641 + * benefit from xSpeed's static-rewrite; the question is only
642 + * which nginx is in the cache file's filesystem.
643 + *
644 + * Returns one of:
645 + * 'htaccess' — Apache / LiteSpeed; .htaccess block is
646 + * installed automatically, no user action.
647 + * 'nginx-host' — self-managed nginx on the host (no
648 + * container in the request path). User
649 + * pastes the snippet into their vhost
650 + * (typically /etc/nginx/sites-enabled/<site>).
651 + * 'nginx-container' — nginx running inside the same container
652 + * as PHP. User pastes the snippet into the
653 + * container's nginx config (typically
654 + * docker/nginx.conf in the site's
655 + * docker-compose dir). Host nginx (if any)
656 + * is a reverse-proxy that just forwards
657 + * bytes — snippet does NOT go there.
658 + * 'unknown' — IIS or undetected; treat as manual.
659 + */
660 + public static function rewrite_topology(): string {
661 + $type = self::type();
662 + if ( self::APACHE === $type || self::LITESPEED === $type ) {
663 + return 'htaccess';
664 + }
665 + if ( self::NGINX === $type ) {
666 + return self::is_containerized() ? 'nginx-container' : 'nginx-host';
667 + }
668 + return 'unknown';
669 + }
670 +
101 671 private static function server_signature() {
102 672 return isset( $_SERVER['SERVER_SOFTWARE'] )
103 673 ? sanitize_text_field( wp_unslash( $_SERVER['SERVER_SOFTWARE'] ) )
104 674 : '';
@@ -104,18 +674,34 @@
104 674 : '';
105 675 }
106 676
107 677 /**
108 - * Detect active caching plugins that would conflict with xSpeed. Returns
109 - * a list of human-readable labels for any conflicting plugin currently
110 - * active; empty array means the field is clear. Used by the onboarding
111 - * wizard's Step 1 health check and (Phase 2.1) the main dashboard's
112 - * Health card.
678 + * Active PAGE-CACHING plugins that would fight xSpeed over the cache
679 + * drop-in. Returns human-readable labels; an empty array means the field
680 + * is clear. Used by the onboarding wizard's Step 1 health check and the
681 + * dashboard's Health card, both of which tell the user to deactivate what
682 + * is listed "to avoid double-caching".
113 683 *
114 - * The detection key is the plugin's main file path relative to the
115 - * plugins directory — the same value WordPress uses internally in
116 - * `active_plugins`. Folder-only checks (`is_plugin_active('foo/')`)
117 - * would false-positive on disabled plugins still on disk.
684 + * Which is why the list is filtered on the page-cache capability rather
685 + * than "is it a performance plugin": Autoptimize only minifies, so naming
686 + * it here made the health row give advice that was flatly wrong.
687 + * Minification overlap is still caught — by Conflict_Registry, per feature.
688 + *
689 + * The detection key is the plugin's main file path relative to the plugins
690 + * directory — the same value WordPress uses internally in `active_plugins`.
691 + * Folder-only checks (`is_plugin_active('foo/')`) would false-positive on
692 + * disabled plugins still on disk.
693 + *
694 + * Membership comes from Cache_Plugin_Catalog, so a plugin is added in one
695 + * place and shows up in both this list and the conflict matrix.
696 + *
697 + * Activation is not the whole test, though. What actually stops xSpeed
698 + * enabling its cache is who holds advanced-cache.php, and a drop-in left
699 + * behind by an uninstalled plugin holds it just as firmly as a running
700 + * one. Checking only active_plugins let the wizard say "No other caching
701 + * plugins detected" on the environment step and then refuse the enable on
702 + * the very next step, for a file it had just looked past. So a foreign
703 + * drop-in is listed too, named where we can name it.
118 704 */
119 705 public static function conflicts() {
120 706 if ( ! function_exists( 'is_plugin_active' ) ) {
121 707 require_once ABSPATH . 'wp-admin/includes/plugin.php';
@@ -120,29 +706,53 @@
120 706 if ( ! function_exists( 'is_plugin_active' ) ) {
121 707 require_once ABSPATH . 'wp-admin/includes/plugin.php';
122 708 }
123 709
124 - $known = array(
125 - 'wp-rocket/wp-rocket.php' => 'WP Rocket',
126 - 'w3-total-cache/w3-total-cache.php' => 'W3 Total Cache',
127 - 'wp-super-cache/wp-cache.php' => 'WP Super Cache',
128 - 'wp-fastest-cache/wpFastestCache.php' => 'WP Fastest Cache',
129 - 'litespeed-cache/litespeed-cache.php' => 'LiteSpeed Cache',
130 - 'cache-enabler/cache-enabler.php' => 'Cache Enabler',
131 - 'comet-cache/comet-cache.php' => 'Comet Cache',
132 - 'hummingbird-performance/wp-hummingbird.php' => 'Hummingbird',
133 - 'sg-cachepress/sg-cachepress.php' => 'SG Optimizer',
134 - 'breeze/breeze.php' => 'Breeze',
135 - 'autoptimize/autoptimize.php' => 'Autoptimize',
136 - 'flying-press/flying-press.php' => 'FlyingPress',
137 - 'nitropack/main.php' => 'NitroPack',
138 - );
139 -
140 - $active = array();
141 - foreach ( $known as $file => $label ) {
710 + $found = array();
711 + foreach ( Cache_Plugin_Catalog::with_capability( Cache_Plugin_Catalog::CAP_PAGE_CACHE ) as $file => $entry ) {
712 + // xSpeed is in the catalog — it is a page cache, and the detector
713 + // needs to be able to name our own drop-in. It is not a conflict
714 + // with itself, and listing it told every site running us to
715 + // deactivate us to avoid double-caching.
716 + if ( 'xspeed/xspeed.php' === $file ) {
717 + continue;
718 + }
142 719 if ( is_plugin_active( $file ) ) {
143 - $active[] = $label;
720 + $found[] = $entry['label'];
144 721 }
145 722 }
146 - return $active;
723 +
724 + $dropin = self::foreign_dropin_label();
725 + if ( null !== $dropin && ! in_array( $dropin, $found, true ) ) {
726 + $found[] = $dropin;
727 + }
728 +
729 + return array_values( array_unique( $found ) );
730 + }
731 +
732 + /**
733 + * The name of whoever owns advanced-cache.php, when it is not xSpeed.
734 + *
735 + * Null when the file is absent or ours. An owner we cannot identify still
736 + * blocks the enable, so it is reported under a generic name rather than
737 + * being silently dropped — "we could not tell" and "there is nothing
738 + * there" are different answers.
739 + */
740 + private static function foreign_dropin_label(): ?string {
741 + $owner = Cache::dropin_owner();
742 + if ( Cache::DROPIN_XSPEED === $owner || Cache::DROPIN_NONE === $owner ) {
743 + return null;
744 + }
745 + if ( Cache::DROPIN_UNREADABLE === $owner ) {
746 + return __( 'an unreadable advanced-cache.php', 'xspeed' );
747 + }
748 +
749 + $contents = @file_get_contents( WP_CONTENT_DIR . '/advanced-cache.php' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents, WordPress.PHP.NoSilencedErrors.Discouraged -- read-only inspection of a drop-in we may not own; failure is reported as an unidentified owner.
750 + $named = is_string( $contents ) ? Cache_Plugin_Catalog::identify_dropin( $contents ) : null;
751 + if ( null !== $named ) {
752 + $entry = Cache_Plugin_Catalog::get( $named );
753 + return (string) ( $entry['label'] ?? $named );
754 + }
755 +
756 + return __( 'an unidentified advanced-cache.php', 'xspeed' );
147 757 }
148 758 }