Advanced dynamic smart proxy implementation

The "smart proxy" is so called, because in addition to proxying the requests, it allows you to add in various overrides to dynamically control the Query Engine depending on your own logic, such as showing a different data set to each user.

The smart proxy you implement will receive and then forward all requests to a Vizzly Query Engine, with the addition of a Config-Api-Key header to authenticate the requests, the Vizzly config and optionally encrypted database connection credentials.

Config-Api-Key Header

This API key header value must be added for all requests. The value can be generated by running the CLI command

vizzly dynamic-api-key

This will provide you with the API key itself, and the verification hash that needs to be set on the Vizzly Query Engine as an environment variable VIZZLY_DYNAMIC_CONFIG_AUTH_VERIFY_HASH.

Adding the dynamicConfig value

For all POST requests, for which the content-type header contains a value of application/json, you will add a dynamicConfig value to the request body.

Here is a simple NodeJs example of the logic required;

  const dynamicConfig = ConfigBuilder.buildConfigForUser(req.cookies['user']);

  // Add the `dynamicConfig` property to the body, for POST requests and where content-type is application/json.
  if (
    req.method == 'POST' &&
    req.headers['content-type']?.includes('application/json') &&
    proxiedBody
  ) {

Vizzly Config Structure

The specification of the Vizzly config that defines the data sets to make available on the dashboard, can be found here.

Db-Connection header

Single tenant environments

Using the same encryption key as provided to the Vizzly Query Engine, you can encrypt the connection credentials and provide them in a Db-Connection header for all requests proxied through to the Vizzly Query Engine.

Here is an example of how you might build the encrypted database connection in a NodeJs environment;

import { Encryption } from '@vizzly/auth';
import * as Settings from './Settings';

export const buildConnection = async (): Promise<string> => {
  return await Encryption.encrypt(Settings.getEncryptionSecret(), {
    host: Settings.getDatabaseHost(),
    password: Settings.getDatabasePassword(),
    user: Settings.getDatabaseUser(),
    database: Settings.getDatabaseName()
  });
};

And then adding it to the request as a Db-Connection header

  // OPTIONAL for dynamic DB connections!
  // If you are dynamically changing which database to connect to, you can set the Db-Connection
  // header with an encrypted JSON string containing the connection credentials. Alternatively, you
  // can setup the connection on the Query Engine using environment variables.
  proxiedHeaders[

Example

A NodeJs example written in Typescript can be seen here! (opens in a new tab)