S3 Serve
A node utility for serving files from S3. Compatible with Express, Fastify, NestJs, and more.
Small & flexible. You decide what and how to send and receive.
Install
npm install s3-serve --save
This library has a peer dependency on @aws-sdk/client-s3
, if not already installed, use the following:
npm install @aws-sdk/client-s3
Getting Started
Minimal express example:
import express from 'express';
import { S3Client } from '@aws-sdk/client-s3';
import { s3Get } from 's3-serve';
const client = new S3Client(...);
const app = express();
app.get('/:file', async (req, res) => {
const { headers, body } = await s3Get(client, {
Bucket: 'my-bucket',
Key: req.params.file
});
res.set(headers);
body.pipe(res);
})
More elaborate example at the end!
Why?
There are many libraries that can help in serving file from S3, such as s3-server, s3-autoindex,s3-proxy, simple-s3-proxy, s3-files, s3-streams and many more. Unfortunately, many of them are unmaintained, and the ones who are, are very restrictive in what the allow.
This library aims to be flexible by giving the developer full control over the inputs and outputs of each request, while also reducing the amount of boilerplate required when working with @aws-sdk/s3-client
.
API
s3Get
s3Get(client: S3 Client, options: GetObjectCommandInput): Promise<S3Response>
Executes a GetObjectCommand using the given client. Returns an S3Response which contains all information needed to serve the file.
Note: s3Get
does neither cache nor store anything in memory, the requested file in S3Response.body
is a Readable
stream that can be piped as a response.
extractGetArgs
extractGetArgs(headers: object): object
Extracts and converts relevant headers from a request, so they can be fed into s3Get
's GetObjectCommandInput
.
Complex example
Implement express.static
but from s3 and with custom cache headers:
import { s3Get, extractGetArgs } from 's3-serve';
app.get('/:key(*)', async (req, res) => {
const response = await s3Get(client, {
Bucket,
Key: req.params.key || 'index.html',
...extractGetArgs(req.headers),
});
if (response.error) {
const { error, metadata, statusCode, statusMessage } = response;
console.error(`Error ${statusCode} getting ${Key}`, error, metadata);
res.status(statusCode).send(statusMessage);
return;
}
const { statusCode, headers, body } = response;
res.status(statusCode).set(headers);
if (/\.(jpg|png|gif)$/.test(Key)) {
res.set('cache-control', 'max-age=3600');
}
body.pipe(res);
});