Adminer login plugin for authenticated reverse proxy setup. for eg: auth_request in nginx

mysite.nginx.conf

	location /dba/ {
		auth_request /auth/check_login/;
		error_page  403   /auth/login/;

		# Server running dba tool
		proxy_pass http://127.0.0.1:7777/;
		proxy_set_header Host $host;
		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

		auth_request_set $auth_db_vendor $upstream_http_db_vendor;
		proxy_set_header db_vendor $auth_db_vendor;
		auth_request_set $auth_db_server $upstream_http_db_server;
		proxy_set_header db_server $auth_db_server;
		auth_request_set $auth_db_username $upstream_http_db_username;
		proxy_set_header db_username $auth_db_username;
		auth_request_set $auth_db_password $upstream_http_db_password;
		proxy_set_header db_password $auth_db_password;
		auth_request_set $auth_db_name $upstream_http_db_name;
		proxy_set_header db_name $auth_db_name;

	}

proxy-login.php

<?php
/*
 * ഓം ബ്രഹ്മാർപ്പണം 
 * plugins/proxy-login.php
 * Created: Sat Jul 17 2021 03:00:25 GMT+0530 (GMT+05:30)
 * Copyright 2021 Harish Karumuthil<harish2704@gmail.com>
 *
 * This Plugin allows to run adminer behind a authenticated reverse proxy 
 * using custom authentication method.
 * For example, we can use auth_request module in Nginx to authenticate
 * Then authntication server need to return credentials via response headers
 */

class AdminerProxyLogin {

	function __construct() {
		$this->vendor   = $_SERVER['HTTP_DB_VENDOR'];
		$this->server   = $_SERVER['HTTP_DB_SERVER'];
		$this->username = $_SERVER['HTTP_DB_USERNAME'];
		$this->password = $_SERVER['HTTP_DB_PASSWORD'];
		$this->db       = $_SERVER['HTTP_DB_NAME'];

		$_GET['pgsql'] = $this->server;
		$_GET['username'] = $this->username;
		$_GET['db'] = $this->db;
		$_GET['ns'] = 'public';

		$_SESSION["db"] = [ $this->vendor => [
			$this->server => [
				$this->username => [
					$this->db => true
				]
			]
		] ];

		$_SESSION["pwds"] = [ $this->vendor => [
			$this->server => [
				$this->username => $this->password
			]
		] ];
	}
	
	function credentials() {
		return array( SERVER, $this->username, $this->password);
	}
	
	function login($login, $password) {
		return true;
	}
	
	function loginForm() {
		echo "<hr/><b>Not allowed</b>";
		return true;
	}
}