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.