m11s/s3-upload-proxy repository overview

⁠m11s/s3-upload-proxy

Minimal Node.js service that accepts multipart file uploads over HTTP and stores them in any S3-compatible object store (MinIO, Cloudflare R2, AWS S3).

⁠What this is

Browsers cannot upload directly to MinIO without exposing credentials. This proxy sits in between: it receives a multipart/form-data POST from the browser, signs and forwards the file to S3 using server-side credentials, and returns the public URL of the stored object.

It is the server-side counterpart to the @m11s-io/decap-cms-media-library-s3⁠ browser plugin, but is otherwise generic — any frontend that can POST a file can use it.

Built from the @m11s-io/s3-upload-proxy⁠ npm package.

⁠API

POST /upload[/:tenant]
Content-Type: multipart/form-data

file=<binary>

Returns:

{ "url": "https://minio.example.com/bucket/prefix/tenant/1234567890-filename.jpg" }

The optional :tenant path segment is appended to the key prefix, allowing one instance to serve multiple tenants without credential isolation.

⁠Configuration

All configuration is via environment variables:

⁠Example

docker run -p 8082:8082 \
  -e S3_ENDPOINT=https://minio.example.com \
  -e S3_BUCKET=my-bucket \
  -e S3_PUBLIC_URL=https://minio.example.com/my-bucket \
  -e S3_ACCESS_KEY=mykey \
  -e S3_SECRET_KEY=mysecret \
  -e S3_KEY_PREFIX=uploads \
  m11s/s3-upload-proxy:0.1.3

Upload a file:

curl -F "[email protected]" http://localhost:8082/upload/mytenant
# {"url":"https://minio.example.com/my-bucket/uploads/mytenant/1234567890-photo.jpg"}