Check for out of disk space

Fixes #567

src/cron.js

@@ -25,7 +25,8 @@ var gAutoupdaterJob = null,
     gCleanupTokensJob = null,
     gDockerVolumeCleanerJob = null,
     gSchedulerSyncJob = null,
-    gCertificateRenewJob = null;
+    gCertificateRenewJob = null,
+    gCheckDiskSpaceJob = null;
 
 var NOOP_CALLBACK = function (error) { if (error) console.error(error); };
 
@@ -69,6 +70,14 @@ function recreateJobs(unusedTimeZone, callback) {
             timeZone: allSettings[settings.TIME_ZONE_KEY]
         });
 
+        if (gCheckDiskSpaceJob) gCheckDiskSpaceJob.stop();
+        gCheckDiskSpaceJob = new CronJob({
+            cronTime: '00 30 */4 * * *', // every 4 hours
+            onTick: cloudron.checkDiskSpace,
+            start: true,
+            timeZone: allSettings[settings.TIME_ZONE_KEY]
+        });
+
         if (gBoxUpdateCheckerJob) gBoxUpdateCheckerJob.stop();
         gBoxUpdateCheckerJob = new CronJob({
             cronTime: '00 */10 * * * *', // every 10 minutes