Kuzzle Plugin S3

S3 has a right system to limit who can upload files to buckets.

Presigned URLs are special disposable Urls generated by S3. It is possible to upload a file directly to one of these URLs so that it can be stored into the bucket.

These URLs must be generated on the server side, this plugin includes among other things the generation of these URLs so that developers can then send their files directly to S3 from a client application.

Compatibility matrix

Kuzzle Version	Plugin Version
1.x.x	1.x.x
2.x.x	2.x.x

Usage

Get a Presigned URL:

// Kuzzle request
{
  "controller": "s3/upload",
  "action": "getUrl",
  "filename": "headcrab.png",
  "uploadDir": "xen"
}

// Kuzzle response
{
  "fileKey": "xen/<uuid>-headcrab.png",
  "uploadUrl": "https://s3.eu-west-3.amazonaws.com/...",
  "fileUrl": "https://s3.eu-west-3.amazonaws.com/...",
  "ttl": 1200000
}

Then send a PUT request to the uploadUrl URL with the body set to the file's content and a Content-Type header corresponding to the file mime type.

Finally, validate the uploaded file. If not validated in a timely manner (the TTL is configurable), the uploaded file is automatically removed.

// Kuzzle request
{
  "controller": "s3/upload",
  "action": "validate",
  "fileKey": "xen/<uuid>-headcrab.png"
}

Example using the Javascript SDK

  // Get a Presigned URL
  const file = document.getElementById('uploadInput').files[0];
  const { result } = await kuzzle.query({
    controller: 's3/upload',
    action: 'getUrl',
    uploadDir: 'xen',
    filename: file.name
  });

  // Upload the file directly to S3
  const axiosOptions = {
    headers: {
      'Content-Type': file.type
    }
  };
  await axios.put(result.uploadUrl, file, axiosOptions);

  // Validate the uploaded file
  await kuzzle.query({
    controller: 's3/upload',
    action: 'validate',
    fileKey: result.fileKey
  });

You can see a full example here: test/s3-upload-test.html

API

upload:getUrl

Returns a Presigned URL to upload directly to S3.
The URL is only valid for a specified period of time. (Configurable in the kuzzlerc file)

File uploaded to the generated URL must be validated with upload:validate otherwise they will be deleted after the same TTL as for the URL expiration.

Request format:

{
  // Kuzzle API params
  "controller": "s3/upload",
  "action": "getUrl",

  // Uploaded file name
  "filename": "headcrab.png", 
  // Upload directory
  "uploadDir": "xen" 
}

Response result format:

{
  // File key in S3 bucket
  "fileKey": "xen/<uuid>-headcrab.png", 
  // Presigned upload URL
  "uploadUrl": "https://s3.eu-west-3.amazonaws.com/...", 
  // Public file URL after successful upload
  "fileUrl": "https://s3.eu-west-3.amazonaws.com/...", 
  // TTL in ms for the URL validity and before the uploaded file deletion
  "ttl": 1200000 
}

upload:validate

Validate and persist a previsously uploaded file.
Without a call to the action, every file uploaded on a Presigned URL will be deleted after a TTL.

Request format:

{
  // Kuzzle API params
  "controller": "s3/upload",
  "action": "validate",

  // File key in S3 bucket
  "fileKey": "xen/<uuid>-headcrab.png" 
}

Response result format:

{
  // File key in S3 bucket
  "fileKey": "xen/<uuid>-headcrab.png", 
  // Public file URL after successful upload
  "fileUrl": "https://s3.eu-west-3.amazonaws.com/..." 
}

file:getUrl

Returns the public file URL.

Request format:

{
  // Kuzzle API params
  "controller": "s3/file",
  "action": "getUrl",

  // File key in S3 bucket
  "fileKey": "xen/<uuid>-headcrab.png" 
}

Response result format:

{
  // Public file URL after successful upload
  "fileUrl": "https://s3.eu-west-3.amazonaws.com/..." 
}

file:delete

Deletes an uploaded file from S3.

Request format:

{
  // Kuzzle API params
  "controller": "s3/file",
  "action": "delete",

  "fileKey": "xen/<uuid>-headcrab.png" // File key in S3 bucket
}

file:getFilesKeys

List the files keys uploaded to an S3 Bucket.

Request format:

{
  // Kuzzle API params
  "controller": "s3/file",
  "action": "getFilesKeys",
}

Configuration

You need to set your AWS access key in the environment: AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.
Your access key must have the following rights: PutObject and DeleteObject.

Then in your kuzzlerc file, you can change the following configuration variable:

{
  "plugins": {
    "s3": {
      // AWS S3 bucket
      "bucketName": "your-s3-bucket",
      // AWS S3 compatible service endpoint. It must include the protocol and port.
      "endpoint": "https://s3.eu-west-3.amazonaws.com",
      // AWS S3 client configuration options.
      "s3ClientOptions": {
        "s3ForcePathStyle": false
      },      
      // TTL in ms before Presigned URL expire or the uploaded file is deleted
      "signedUrlTTL": 1200000,
      // Redis key prefix
      "redisPrefix": "s3Plugin/uploads"
    }
  }
}

In addition to Amazon aws s3, this plugin allows you to use any S3-Api compatible service accesible through the AWS-S3 sdk. Any specific configuration option can be added to the s3ClientOptions configuration attribute. Please note that the parameters are translated directly, so refer to the sdk documentation to available options.

AWS S3 Bucket

First you must configure your bucket to allow public access to uploaded files.
Go to the Permissions tab in your bucket configuration and in Bucket Policy add the following statement:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "AddPerm",
      "Effect": "Allow",
      "Principal": "*",
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::your-bucket-name/*"
    }
  ]
}

Then you have to allow Cross Origin Request by editing the CORS Configuration:

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<CORSRule>
    <AllowedOrigin>your-app-domain.com</AllowedOrigin>
    <AllowedMethod>GET</AllowedMethod>
    <AllowedMethod>PUT</AllowedMethod>
    <AllowedMethod>POST</AllowedMethod>
    <MaxAgeSeconds>3000</MaxAgeSeconds>
    <AllowedHeader>Content-Type</AllowedHeader>
    <AllowedHeader>Authorization</AllowedHeader>
</CORSRule>
</CORSConfiguration>

Installation

On an existing Kuzzle stack

Clone this repository in your plugins/available directory and then link it to the plugins/enabled directory.

Then go to your plugin directory and run the following command npm install.

For more information, refer to the official documentation: https://docs.kuzzle.io/guide/2/essentials/plugins/#installing-a-plugin

Local setup

You can use the docker-composer.yml file provided in this repository to start a Kuzzle stack with this plugin pre-installed.

You have to provide valid credentials for AWS S3 through the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

export AWS_ACCESS_KEY_ID=your-access-key
export AWS_SECRET_ACCESS_KEY=your-secret-key

docker-compose -f docker-compose.yml up

Then you can open the file test/s3-upload-test.html in your browser.