MDL-66570 admin: Add setting to hide captured cron log output

admin/settings/server.php

@@ -271,6 +271,14 @@ $temp->add(
         ]
     )
 );
+$temp->add(
+    new admin_setting_configcheckbox(
+        'task_logtostdout',
+        new lang_string('task_logtostdout', 'admin'),
+        new lang_string('task_logtostdout_desc', 'admin'),
+        1
+    )
+);
 
 if (\core\task\logmanager::uses_standard_settings()) {
     $temp->add(

lang/en/admin.php

@@ -1213,6 +1213,8 @@ $string['task_logretention'] = 'Retention period';
 $string['task_logretention_desc'] = 'The maximum period that logs should be kept for. This setting interacts with the \'Retain runs\' setting: whichever is reached first will apply';
 $string['task_logretainruns'] = 'Retain runs';
 $string['task_logretainruns_desc'] = 'The number of runs of each task to retain. This setting interacts with the \'Retention period\' setting: whichever is reached first will apply.';
+$string['task_logtostdout'] = 'Display log output';
+$string['task_logtostdout_desc'] = 'When jobs are running and the output is captured, whether the captured output should also be displayed as the task runs.';
 $string['task_type:adhoc'] = 'Ad hoc';
 $string['task_type:scheduled'] = 'Scheduled';
 $string['task_result:failed'] = 'Fail';

lib/classes/task/logmanager.php

@@ -76,13 +76,18 @@ class logmanager {
      */
     protected static $oblevel = null;
 
+    /**
+     * @var bool Output logged content to screen.
+     */
+    protected static $outputloggedcontent = true;
+
     /**
      * Create a new task logger for the specified task, and prepare for logging.
      *
      * @param   \core\task\task_base    $task The task being run
      */
     public static function start_logging(task_base $task) {
-        global $DB;
+        global $CFG, $DB;
 
         if (!self::should_log()) {
             return;
@@ -129,6 +134,8 @@ class logmanager {
             self::$oblevel = null;
         }
 
+        self::$outputloggedcontent = !empty($CFG->task_logtostdout);
+
         // Start capturing output.
         ob_start([\core\task\logmanager::class, 'add_line'], self::CHUNKSIZE);
     }
@@ -336,6 +343,10 @@ class logmanager {
             fwrite(self::$fh, $log);
         }
 
-        return $log;
+        if (self::$outputloggedcontent) {
+            return $log;
+        } else {
+            return '';
+        }
     }
 }

lib/moodlelib.php

@@ -9090,11 +9090,11 @@ function mtrace($string, $eol="\n", $sleep=0) {
         $fn($string, $eol);
         return;
     } else if (defined('STDOUT') && !PHPUNIT_TEST && !defined('BEHAT_TEST')) {
-        fwrite(STDOUT, $string.$eol);
-
         // We must explicitly call the add_line function here.
         // Uses of fwrite to STDOUT are not picked up by ob_start.
-        \core\task\logmanager::add_line("{$string}{$eol}");
+        if ($output = \core\task\logmanager::add_line("{$string}{$eol}")) {
+            fwrite(STDOUT, $output);
+        }
     } else {
         echo $string . $eol;
     }

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2019091300.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2019091700.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.