Fixes #6978 Empty output for archiving when using the web cron

core/Log/WebCronArchiveLogger.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Piwik\Log;
+
+use Monolog\Logger;
+use Psr\Log\AbstractLogger;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Basic logger that streams messages to stdout.
+ *
+ * This logger is used in the archiving when archive.php is called from a HTTP request. In that specific case,
+ * we want to log to stdout.
+ *
+ * @see misc/cron/archive.php
+ */
+class WebCronArchiveLogger extends AbstractLogger implements LoggerInterface
+{
+    public function log($level, $message, array $context = array())
+    {
+        if ($level <= Logger::DEBUG) {
+            return;
+        }
+        echo $message . "\n";
+    }
+}

misc/cron/archive.php

@@ -10,6 +10,7 @@
  */
 
 use Piwik\Container\StaticContainer;
+use Piwik\Log\WebCronArchiveLogger;
 use Symfony\Bridge\Monolog\Handler\ConsoleHandler;
 use Symfony\Component\Console\Output\ConsoleOutput;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -66,6 +67,9 @@
         /** @var ConsoleHandler $consoleLogHandler */
         $consoleLogHandler = StaticContainer::getContainer()->get('Symfony\Bridge\Monolog\Handler\ConsoleHandler');
         $consoleLogHandler->setOutput(new ConsoleOutput(OutputInterface::VERBOSITY_VERBOSE));
+    } else {
+        // HTTP request: logs needs to be dumped on stdout
+        StaticContainer::getContainer()->set('Psr\Log\LoggerInterface', new WebCronArchiveLogger);
     }
 
     $archiver = new Piwik\CronArchive();