Delete outdated files from Rocket.Chat

outdated_files_query.js

/**
 * MongoDB query to delete outdated files from Rocket.Chat. You can specify the number of DAYS
 * before a file is considered outdated. Deleted files are removed from GridFS completely keeping
 * only the message in chat. The message is modified to be a link that points to ALT_LINK instead
 * of the file and '(deleted)' is appended to the title.
 * 
 * Tested with MongoDB 3.4
 */

const DAYS = 60;
const ALT_LINK = "/terms-of-service";
let count = 0;

/* Find all messages with files attached */
db.rocketchat_message.find(
  {
    ts: { $lt: new Date(new Date().getTime() - 1000 * 60 * 60 * 24 * DAYS) },
    file: { $exists: true },
    attachments: {
      $elemMatch: { type: "file" }
    }
  }
).forEach(function(msg) {
  count++;
  var oldTitle = msg.attachments.find(function(a) {
    return a.type === "file";
  }).title;

  /* Delete file from GridFS */
  db.rocketchat_uploads.remove({ _id: msg.file._id }, true);
  db.rocketchat_uploads.files.remove({ _id: msg.file._id }, true);
  db.rocketchat_uploads.chunks.remove({ files_id: msg.file._id }, true);


  /* Update message to reflect deletion */
  db.rocketchat_message.updateOne(
    { 
      _id: msg._id,
      attachments: {
        $elemMatch: { type: "file" }
      }
    },
    {
      $set: {
        "attachments.$.type": "link",
        "attachments.$.title": oldTitle + " (deleted)",
        "attachments.$.title_link": ALT_LINK,
        "attachments.$.title_link_download": false
      },
      $unset: {
        "file": true,
        "attachments.$.image_url": true,
        "attachments.$.image_type": true,
        "attachments.$.image_size": true
      }
    }
  );
});

print('Successfully deleted ' + count + ' files.');