serve-gridfs

Middleware to serve static files using mongodb gridfs

Based on serve-static

Tested on node 7.x, npm 4.x

Require node-mongodb-native 2.x

Install

$ npm i serve-gridfs

API

import serveGridfs from 'serve-gridfs'
 

serveGridfs(mongoConnection, { options })

Create a new middleware function to serve files from a mongodb gridfs collection. The file to be served is based on req.url. In a default setting, when a file is not found, this middleware call next(), instead of returning 404, to be in line with the express serve-static middleware.

mongoConnection

Internally, this middleware use promised based mongo client, so pass in the connection detail here.

const mongoConnection = MongoClient.connect('mongodb://localhost:27017/myApp')

Options

All options are optional

Key	Type	Default	Note
bucketName	string	'fs'	Default set by mongodb
chunkSizeBytes	number	261120	255 * 1024
writeConcern	object	null
readPreference	object	null
byId	bool	true	The file sepecified in req.url by default is the mongodb _id, if set to false, mongodb will look for filename instead of _id, see example below. When multiple files have the same filename, by default, the latest file will be served
acceptRanges	bool	true	Setting to false will not send Accept-Ranges and ignore the contents of the Range request header
cacheControl	bool or string	true	Setting to false will disable the Cache-Control in a response header. The default is public, max-age=0. You can set this to any string, which will also overide the maxAge key below.
maxAge	number	0	Set this to whatever you like in seconds
etag	bool	true	md5 generated by mongodb gridfs
lastModified	bool	true
fallthrough	bool	true	By default, when the file specified in req.url cannot be found in mongodb gridfs collection, a next() will be called without an error. If set to false, a next(new Error('FileNotFound)) will be called. Also, setting to false will throw a 405 http status code if req.method is not GET or HEAD
setHeaders	function	null	signature function (res, path, stat) {}. path is the requested file path, the stat is the stat of the file if present, produced by mongodb fs.files, typically, it is { _id, length, chuckSize, uploadDate, md5, filename }, see uploadStream

Example

// with express js
 
import express from 'express'
import { MongoClient, GridFSBucket } from 'mongodb'
import serveGridfs from 'serve-gridfs'
 
const app = express()
const mongoConnection = MongoClient.connect('mongodb://localhost:27017/myApp')
 
app.use('/uploads', serveGridfs(mongoConnection))
app.use('/uploads_byname', serveGridfs(mongoConnection, { byId: false }))
 
const options = {
  bucketName: 'somethingElse',
  setHeaders(res, path, stat) {
    if (stat && stat.contentType === 'application/pdf' && stat.length > 102400000) res.setHeader('Content-Disposition', 'attachment; filename = ' + path)
  }
}
app.use('/uploads2', serveGridfs(mongoConnection, { bucketName: 'somethingElse' }))
 

Retriving a file

# Assuming there is a file with an _id of 001 and a filename of cat.png in mongodb gridfs collection, the following commands will retrieve the same file 
 
$ curl http://localhost:3000/uploads/001
$ curl http://localhost:3000/uploads_byname/cat.png
 
 

Notes

• Due to gridfs configuration, you can have an _id or filename containing slash, such as cat/001 or cat/tom.png as an _id and filename respectively. In this case, curl http://localhost:3000/uploads/cat/001 and curl http://localhost:3000/uploads_byname/cat/tom.png will resolve to the same file.