Upgrade/Install: Automatically roll back to the previous version when an automatic plugin update results in a fatal error on the front end of the site.

This builds on the temporary backup system introduced in 6.3 to allow automatic updates to benefit from fatal error protection. A loopback request is performed to the home page of the site and the plugin is rolled back to its backed up version if a fatal error is observed.

For debugging and observability during beta, this change includes several calls to `error_log()` during the upgrade and rollback stages. These calls can be removed or placed behind a flag once we're ready for RC1.

Props costdev, johnbillion, mukesh27, afragen, audrasjb, justlevine, kirasong, peterwilsoncc

Fixes #58281

Built from https://develop.svn.wordpress.org/trunk@58128


git-svn-id: http://core.svn.wordpress.org/trunk@57593 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
John Blackbourn 2024-05-10 11:48:15 +00:00
parent 6edbf28fec
commit 1e8d651f23
4 changed files with 279 additions and 9 deletions

View File

@ -446,6 +446,29 @@ class WP_Automatic_Updater {
$allow_relaxed_file_ownership = true;
}
if ( 'plugin' === $type ) {
$was_active = is_plugin_active( $upgrader_item );
error_log( ' Upgrading plugin ' . var_export( $item->slug, true ) . '...' );
}
if ( 'theme' === $type ) {
error_log( ' Upgrading theme ' . var_export( $item->theme, true ) . '...' );
}
/*
* Enable maintenance mode before upgrading the plugin or theme.
*
* This avoids potential non-fatal errors being detected
* while scraping for a fatal error if some files are still
* being moved.
*
* While these checks are intended only for plugins,
* maintenance mode is enabled for all upgrade types as any
* update could contain an error or warning, which could cause
* the scrape to miss a fatal error in the plugin update.
*/
$upgrader->maintenance_mode( true );
// Boom, this site's about to get a whole new splash of paint!
$upgrade_result = $upgrader->upgrade(
$upgrader_item,
@ -460,6 +483,17 @@ class WP_Automatic_Updater {
)
);
/*
* After WP_Upgrader::upgrade() completes, maintenance mode is disabled.
*
* Re-enable maintenance mode while attempting to detect fatal errors
* and potentially rolling back.
*
* This avoids errors if the site is visited while fatal errors exist
* or while files are still being moved.
*/
$upgrader->maintenance_mode( true );
// If the filesystem is unavailable, false is returned.
if ( false === $upgrade_result ) {
$upgrade_result = new WP_Error( 'fs_unavailable', __( 'Could not access filesystem.' ) );
@ -486,6 +520,92 @@ class WP_Automatic_Updater {
}
}
if ( 'theme' === $type ) {
error_log( ' Theme ' . var_export( $item->theme, true ) . ' has been upgraded.' );
}
if ( 'plugin' === $type ) {
error_log( ' Plugin ' . var_export( $item->slug, true ) . ' has been upgraded.' );
if ( is_plugin_inactive( $upgrader_item ) ) {
error_log( ' ' . var_export( $upgrader_item, true ) . ' is inactive and will not be checked for fatal errors.' );
}
if ( $was_active && ! is_wp_error( $upgrade_result ) ) {
/*
* The usual time limit is five minutes. However, as a loopback request
* is about to be performed, increase the time limit to account for this.
*/
if ( function_exists( 'set_time_limit' ) ) {
set_time_limit( 10 * MINUTE_IN_SECONDS );
}
/*
* Avoids a race condition when there are 2 sequential plugins that have
* fatal errors. It seems a slight delay is required for the loopback to
* use the updated plugin code in the request. This can cause the second
* plugin's fatal error checking to be inaccurate, and may also affect
* subsequent plugin checks.
*/
sleep( 2 );
if ( $this->has_fatal_error() ) {
$upgrade_result = new WP_Error();
$temp_backup = array(
array(
'dir' => 'plugins',
'slug' => $item->slug,
'src' => WP_PLUGIN_DIR,
),
);
$backup_restored = $upgrader->restore_temp_backup( $temp_backup );
if ( is_wp_error( $backup_restored ) ) {
$upgrade_result->add(
'plugin_update_fatal_error_rollback_failed',
sprintf(
/* translators: %s: The plugin's slug. */
__( "The update for '%s' contained a fatal error. The previously installed version could not be restored." ),
$item->slug
)
);
$upgrade_result->merge_from( $backup_restored );
} else {
$upgrade_result->add(
'plugin_update_fatal_error_rollback_successful',
sprintf(
/* translators: %s: The plugin's slug. */
__( "The update for '%s' contained a fatal error. The previously installed version has been restored." ),
$item->slug
)
);
$backup_deleted = $upgrader->delete_temp_backup( $temp_backup );
if ( is_wp_error( $backup_deleted ) ) {
$upgrade_result->merge_from( $backup_deleted );
}
}
/*
* Should emails not be working, log the message(s) so that
* the log file contains context for the fatal error,
* and whether a rollback was performed.
*
* `trigger_error()` is not used as it outputs a stack trace
* to this location rather than to the fatal error, which will
* appear above this entry in the log file.
*/
error_log( ' ' . implode( "\n", $upgrade_result->get_error_messages() ) );
} else {
error_log( ' The update for ' . var_export( $item->slug, true ) . ' has no fatal errors.' );
}
}
}
// All processes are complete. Allow visitors to browse the site again.
$upgrader->maintenance_mode( false );
$this->update_results[ $type ][] = (object) array(
'item' => $item,
'result' => $upgrade_result,
@ -514,6 +634,8 @@ class WP_Automatic_Updater {
return;
}
error_log( 'Automatic updates starting...' );
// Don't automatically run these things, as we'll handle it ourselves.
remove_action( 'upgrader_process_complete', array( 'Language_Pack_Upgrader', 'async_upgrade' ), 20 );
remove_action( 'upgrader_process_complete', 'wp_version_check' );
@ -524,24 +646,35 @@ class WP_Automatic_Updater {
wp_update_plugins(); // Check for plugin updates.
$plugin_updates = get_site_transient( 'update_plugins' );
if ( $plugin_updates && ! empty( $plugin_updates->response ) ) {
error_log( ' Automatic plugin updates starting...' );
foreach ( $plugin_updates->response as $plugin ) {
$this->update( 'plugin', $plugin );
}
// Force refresh of plugin update information.
wp_clean_plugins_cache();
error_log( ' Automatic plugin updates complete.' );
}
// Next, those themes we all love.
wp_update_themes(); // Check for theme updates.
$theme_updates = get_site_transient( 'update_themes' );
if ( $theme_updates && ! empty( $theme_updates->response ) ) {
error_log( ' Automatic theme updates starting...' );
foreach ( $theme_updates->response as $theme ) {
$this->update( 'theme', (object) $theme );
}
// Force refresh of theme update information.
wp_clean_themes_cache();
error_log( ' Automatic theme updates complete.' );
}
error_log( 'Automatic updates complete.' );
// Next, process any core update.
wp_version_check(); // Check for core updates.
$core_update = find_core_auto_update();
@ -1163,7 +1296,7 @@ class WP_Automatic_Updater {
// List failed plugin updates.
if ( ! empty( $failed_updates['plugin'] ) ) {
$body[] = __( 'These plugins failed to update:' );
$body[] = __( 'The following plugins failed to update. If there was a fatal error in the update, the previously installed version has been restored.' );
foreach ( $failed_updates['plugin'] as $item ) {
$body_message = '';
@ -1551,4 +1684,84 @@ Thanks! -- The WordPress Team"
wp_mail( $email['to'], wp_specialchars_decode( $email['subject'] ), $email['body'], $email['headers'] );
}
/**
* Performs a loopback request to check for potential fatal errors.
*
* Fatal errors cannot be detected unless maintenance mode is enabled.
*
* @since 6.6.0
*
* @global int $upgrading The Unix timestamp marking when upgrading WordPress began.
*
* @return bool Whether a fatal error was detected.
*/
protected function has_fatal_error() {
global $upgrading;
$maintenance_file = ABSPATH . '.maintenance';
if ( ! file_exists( $maintenance_file ) ) {
return false;
}
require $maintenance_file;
if ( ! is_int( $upgrading ) ) {
return false;
}
$scrape_key = md5( $upgrading );
$scrape_nonce = (string) $upgrading;
$transient = 'scrape_key_' . $scrape_key;
set_transient( $transient, $scrape_nonce, 30 );
$cookies = wp_unslash( $_COOKIE );
$scrape_params = array(
'wp_scrape_key' => $scrape_key,
'wp_scrape_nonce' => $scrape_nonce,
);
$headers = array(
'Cache-Control' => 'no-cache',
);
/** This filter is documented in wp-includes/class-wp-http-streams.php */
$sslverify = apply_filters( 'https_local_ssl_verify', false );
// Include Basic auth in the loopback request.
if ( isset( $_SERVER['PHP_AUTH_USER'] ) && isset( $_SERVER['PHP_AUTH_PW'] ) ) {
$headers['Authorization'] = 'Basic ' . base64_encode( wp_unslash( $_SERVER['PHP_AUTH_USER'] ) . ':' . wp_unslash( $_SERVER['PHP_AUTH_PW'] ) );
}
// Time to wait for loopback request to finish.
$timeout = 50; // 50 seconds.
error_log( ' Scraping home page...' );
$needle_start = "###### wp_scraping_result_start:$scrape_key ######";
$needle_end = "###### wp_scraping_result_end:$scrape_key ######";
$url = add_query_arg( $scrape_params, home_url( '/' ) );
$response = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout', 'sslverify' ) );
if ( is_wp_error( $response ) ) {
error_log( 'Loopback request failed: ' . $response->get_error_message() );
return true;
}
// If this outputs `true` in the log, it means there were no fatal errors detected.
error_log( var_export( substr( $response['body'], strpos( $response['body'], '###### wp_scraping_result_start:' ) ), true ) );
$body = wp_remote_retrieve_body( $response );
$scrape_result_position = strpos( $body, $needle_start );
$result = null;
if ( false !== $scrape_result_position ) {
$error_output = substr( $body, $scrape_result_position + strlen( $needle_start ) );
$error_output = substr( $error_output, 0, strpos( $error_output, $needle_end ) );
$result = json_decode( trim( $error_output ), true );
}
delete_transient( $transient );
// Only fatal errors will result in a 'type' key.
return isset( $result['type'] );
}
}

View File

@ -901,6 +901,7 @@ class WP_Upgrader {
$this->skin->set_result( $result );
if ( is_wp_error( $result ) ) {
// An automatic plugin update will have already performed its rollback.
if ( ! empty( $options['hook_extra']['temp_backup'] ) ) {
$this->temp_restores[] = $options['hook_extra']['temp_backup'];
@ -909,8 +910,12 @@ class WP_Upgrader {
* Actions running on `shutdown` are immune to PHP timeouts,
* so in case the failure was due to a PHP timeout,
* it will still be able to properly restore the previous version.
*
* Zero arguments are accepted as a string can sometimes be passed
* internally during actions, causing an error because
* `WP_Upgrader::restore_temp_backup()` expects an array.
*/
add_action( 'shutdown', array( $this, 'restore_temp_backup' ) );
add_action( 'shutdown', array( $this, 'restore_temp_backup' ), 10, 0 );
}
$this->skin->error( $result );
@ -983,15 +988,25 @@ class WP_Upgrader {
*/
public function maintenance_mode( $enable = false ) {
global $wp_filesystem;
if ( ! $wp_filesystem ) {
require_once ABSPATH . 'wp-admin/includes/file.php';
WP_Filesystem();
}
$file = $wp_filesystem->abspath() . '.maintenance';
if ( $enable ) {
$this->skin->feedback( 'maintenance_start' );
if ( ! wp_doing_cron() ) {
$this->skin->feedback( 'maintenance_start' );
}
// Create maintenance file to signal that we are upgrading.
$maintenance_string = '<?php $upgrading = ' . time() . '; ?>';
$wp_filesystem->delete( $file );
$wp_filesystem->put_contents( $file, $maintenance_string, FS_CHMOD_FILE );
} elseif ( ! $enable && $wp_filesystem->exists( $file ) ) {
$this->skin->feedback( 'maintenance_end' );
if ( ! wp_doing_cron() ) {
$this->skin->feedback( 'maintenance_end' );
}
$wp_filesystem->delete( $file );
}
}
@ -1133,17 +1148,33 @@ class WP_Upgrader {
* Restores the plugin or theme from temporary backup.
*
* @since 6.3.0
* @since 6.6.0 Added the `$temp_backups` parameter.
*
* @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
*
* @param array[] $temp_backups {
* Optional. An array of temporary backups.
*
* @type array ...$0 {
* Information about the backup.
*
* @type string $dir The temporary backup location in the upgrade-temp-backup directory.
* @type string $slug The item's slug.
* @type string $src The directory where the original is stored. For example, `WP_PLUGIN_DIR`.
* }
* }
* @return bool|WP_Error True on success, false on early exit, otherwise WP_Error.
*/
public function restore_temp_backup() {
public function restore_temp_backup( array $temp_backups = array() ) {
global $wp_filesystem;
$errors = new WP_Error();
foreach ( $this->temp_restores as $args ) {
if ( empty( $temp_backups ) ) {
$temp_backups = $this->temp_restores;
}
foreach ( $temp_backups as $args ) {
if ( empty( $args['slug'] ) || empty( $args['src'] ) || empty( $args['dir'] ) ) {
return false;
}
@ -1186,17 +1217,33 @@ class WP_Upgrader {
* Deletes a temporary backup.
*
* @since 6.3.0
* @since 6.6.0 Added the `$temp_backups` parameter.
*
* @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
*
* @param array[] $temp_backups {
* Optional. An array of temporary backups.
*
* @type array ...$0 {
* Information about the backup.
*
* @type string $dir The temporary backup location in the upgrade-temp-backup directory.
* @type string $slug The item's slug.
* @type string $src The directory where the original is stored. For example, `WP_PLUGIN_DIR`.
* }
* }
* @return bool|WP_Error True on success, false on early exit, otherwise WP_Error.
*/
public function delete_temp_backup() {
public function delete_temp_backup( array $temp_backups = array() ) {
global $wp_filesystem;
$errors = new WP_Error();
foreach ( $this->temp_backups as $args ) {
if ( empty( $temp_backups ) ) {
$temp_backups = $this->temp_backups;
}
foreach ( $temp_backups as $args ) {
if ( empty( $args['slug'] ) || empty( $args['dir'] ) ) {
return false;
}

View File

@ -420,6 +420,16 @@ function wp_is_maintenance_mode() {
return false;
}
// Don't enable maintenance mode while scraping for fatal errors.
if ( is_int( $upgrading ) && isset( $_REQUEST['wp_scrape_key'], $_REQUEST['wp_scrape_nonce'] ) ) {
$key = stripslashes( $_REQUEST['wp_scrape_key'] );
$nonce = stripslashes( $_REQUEST['wp_scrape_nonce'] );
if ( md5( $upgrading ) === $key && (int) $nonce === $upgrading ) {
return false;
}
}
/**
* Filters whether to enable maintenance mode.
*

View File

@ -16,7 +16,7 @@
*
* @global string $wp_version
*/
$wp_version = '6.6-alpha-58127';
$wp_version = '6.6-alpha-58128';
/**
* Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.