Fix Cron Schedule and new directory includes created inside cron for the cron lock

cron/certificate_refresher.php

@@ -10,7 +10,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 require_once "../config.php";
 

cron/cron.php

@@ -44,12 +44,12 @@ if (php_sapi_name() !== 'cli') {
     die("This script must be run from the command line.\n");
 }
 
-// Tells includes/cron_lock.php and the jobs themselves that they are running under the
+// Tells cron/includes/cron_lock.php and the jobs themselves that they are running under the
 // dispatcher rather than being executed directly. Must be defined before anything else
 // is loaded.
 define('ITFLOW_CRON_DISPATCHER', true);
 
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 require_once "../config.php";
 
 // Set Timezone

cron/domain_refresher.php

@@ -10,7 +10,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 require_once "../config.php";
 

cron/includes/cron_lock.php

@@ -0,0 +1,124 @@
+<?php
+
+/*
+ * ITFlow - Cron runtime: single-run guard and dispatcher support
+ *
+ * Required by each cron script immediately after its CLI check and before config.php,
+ * with the caller setting $cron_lock_script = __FILE__ first.
+ *
+ * Cron work is not safe to run twice at once: autopay charges cards, the mail queue
+ * sends client email, the parser creates tickets. If a run is still going when the next
+ * one fires, those actions can happen twice. The lock name is derived from the calling
+ * script's full path, so it is unique per script and per install - separate ITFlow
+ * instances on one host never block each other, and neither do two different cron
+ * scripts belonging to the same install.
+ *
+ * flock is used rather than a lock file whose presence is checked, because checking for
+ * a file and then creating it is not atomic - two runs starting together can both find
+ * it absent. flock is also released by the kernel however the process exits, so a killed
+ * run leaves nothing stale behind and no age heuristic is needed to clean up after it.
+ *
+ * Contention is not logged: mail_queue and the email parser run every minute, so hitting
+ * a run that is still going is expected, not a fault worth reporting. A lock file that
+ * cannot be opened at all is a real misconfiguration and does report loudly.
+ *
+ * TWO WAYS A CRON SCRIPT RUNS
+ *
+ * Directly (php cron/mail_queue.php): the guard at the bottom of this file takes the
+ * lock and holds it for the life of the process, exactly as it always has.
+ *
+ * Under the dispatcher (cron/cron.php): the dispatcher takes each job's lock itself,
+ * runs the job, and releases it before moving on, so a long job does not hold up the
+ * short ones on the next minute's dispatch. The guard below is skipped in that case -
+ * the lock is already held for this job, and the jobs share one PHP process, so a lock
+ * held for the life of the process would be a lock held for the whole cycle.
+ *
+ * Because the dispatcher shares one process across jobs, a job must never exit() to end
+ * itself early - that would take the rest of the cycle down with it. cronJobStop() is
+ * the replacement: it exits when the script was run directly and unwinds back to the
+ * dispatcher when it wasn't.
+ */
+
+/*
+ * Thrown by cronJobStop() when a job ends itself early under the dispatcher. Carries the
+ * message and exit code the script would have exited with, so the dispatcher can record
+ * why the job stopped.
+ */
+class CronJobStopped extends Exception
+{
+}
+
+/*
+ * End the current cron job early. Direct runs exit exactly as they did before; dispatched
+ * runs unwind to the dispatcher, which records the reason and carries on with the next job.
+ */
+function cronJobStop(string $message = '', int $exit_code = 0): void
+{
+    if (defined('ITFLOW_CRON_DISPATCHER')) {
+        throw new CronJobStopped($message, $exit_code);
+    }
+
+    if ($message !== '') {
+        echo $message;
+    }
+
+    exit($exit_code);
+}
+
+/*
+ * Take the single-run lock for a cron script. $script_path must be the script's own
+ * __FILE__ (or the same resolved path when the dispatcher takes it on the job's behalf),
+ * because that path is what the lock is named after.
+ *
+ * Returns the open handle on success, or false when another run holds the lock. The
+ * handle must stay open for as long as the lock is wanted - closing it releases the lock.
+ */
+function cronLockAcquire(string $script_path)
+{
+    $lock_file = sys_get_temp_dir() . '/itflow_cron_' . md5($script_path) . '.lock';
+
+    $lock_handle = fopen($lock_file, 'c');
+    if ($lock_handle === false) {
+        die("Cannot open the cron lock file at $lock_file - check permissions and open_basedir.\n");
+    }
+
+    if (!flock($lock_handle, LOCK_EX | LOCK_NB)) {
+        // Closing our own handle does not disturb the lock the other run holds on theirs
+        fclose($lock_handle);
+        return false;
+    }
+
+    return $lock_handle;
+}
+
+/*
+ * Release a lock taken by cronLockAcquire(). Only the dispatcher needs this - a direct run
+ * holds its lock until the process ends and the kernel drops it.
+ */
+function cronLockRelease($lock_handle): void
+{
+    if (is_resource($lock_handle)) {
+        flock($lock_handle, LOCK_UN);
+        fclose($lock_handle);
+    }
+}
+
+// Single-run guard for scripts run directly. Skipped under the dispatcher, which locks
+// each job itself - see the note above.
+if (!defined('ITFLOW_CRON_DISPATCHER')) {
+
+    if (!isset($cron_lock_script)) {
+        die("Cron scripts must set \$cron_lock_script = __FILE__ before requiring cron/includes/cron_lock.php.\n");
+    }
+
+    $cron_lock_handle = cronLockAcquire($cron_lock_script);
+
+    if ($cron_lock_handle === false) {
+        // Exit silently. On a per-minute schedule, finding a previous run still going is
+        // normal operation rather than an error, and anything written to stdout here would
+        // be mailed to the crontab owner every single minute for the length of that run.
+        exit(0);
+    }
+
+    // The handle is deliberately left open: the lock is held for the life of the process.
+}

cron/mail_queue.php

@@ -9,7 +9,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 require_once "../config.php";
 require_once "../includes/inc_set_timezone.php";

cron/nightly_tasks.php

@@ -18,7 +18,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 require_once "../config.php";
 

cron/ticket_email_parser.php

@@ -17,7 +17,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 // Autoload (Webklex & any composer deps)
 require_once "../libs/vendor/autoload.php";
@@ -48,7 +48,7 @@ if ($config_ticket_email_parse == 0) {
     cronJobStop("Email Parser: Feature is not enabled - check Settings > Ticketing > Email-to-ticket parsing. See https://docs.itflow.org/ticket_email_parse  -- Quitting..");
 }
 
-// Overlapping runs are prevented by includes/cron_lock.php. This script used to keep a
+// Overlapping runs are prevented by cron/includes/cron_lock.php. This script used to keep a
 // lock file of its own alongside that one, which needed a five minute age heuristic to
 // recover from a killed run and could only end itself with exit() - fatal to a dispatched
 // job. flock covers the same ground and the kernel drops it however the process ends.

cron/ticket_sla.php

@@ -9,7 +9,7 @@ if (php_sapi_name() !== 'cli') {
 
 // Prevent overlapping runs of this script
 $cron_lock_script = __FILE__;
-require_once "../includes/cron_lock.php";
+require_once "includes/cron_lock.php";
 
 require_once "../config.php";
 require_once "../includes/inc_set_timezone.php";