A simple Keykloak REST API wrapper

keycloak-api.php

<?php
class KeycloakApiClient
{

	private $secret;
	public $token;
	private $base_url;

	public function __construct($secret, $base_url) {
		$this->secret = $secret;
		$this->base_url = $base_url;
		$this->token = refreshToken();
	}

	public function get($url = "", $post = null) {
		return $this->go("GET", $url, $post);
	}

	public function post($url, $post = null) {
		return $this->go("POST", $url, $post);
	}

	public function put($url, $post = null) {
		return $this->go("PUT", $url, $post);
	}

	public function delete($url, $post = null) {
		return $this->go("DELETE", $url, $post);
	}

	public function go($method, $url, $post) {
		if (is_null($this->token)) {
			$this->refreshToken();
		}

		if (!is_array($post)) {
			$post = null;
		}
		if (!$url) {
			throw new \Exception("Please enter a destination url");
		}
		$url =  $this->base_url . "/" . $url;
		$headers = $this->getHeaders();

		//GET Override
		if ($method == "GET" && $post !== null) {
			$url .= (strpos($url, "?") === false ? "?" : "") . http_build_query($post);
			$post = "";
		}

		//Setup cURL
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
		curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
		if ($post) {
			curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post));
		}

		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
		curl_setopt($ch, CURLOPT_TIMEOUT, 10);

		$response = trim(curl_exec($ch));
		if (curl_errno($ch)) {
			echo 'Error:' . curl_error($ch);
		}
		$info = curl_getinfo($ch);
		$json = json_decode($response, 1);

		if (!is_array($json)) {
			return $response;
		}

		return $json;
	}

	//Get auth headers for this call
	public function getHeaders() {
		return array(
			"Authorization: Bearer $this->token",
			"Content-Type: application/json",
		);
	}

	private function refreshToken() {
		$ch = curl_init();

		$postfields = "grant_type=client_credentials&" . "client_id=admin-cli&" . "client_secret=$this->secret";

		curl_setopt($ch, CURLOPT_URL, $this->base_url . '/auth/realms/master/protocol/openid-connect/token');
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_POST, 1);
		curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);

		$headers = array();
		$headers[] = 'Content-Type: application/x-www-form-urlencoded';
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
		
		$result = curl_exec($ch);
		if (curl_errno($ch)) {
			echo 'Error:' . curl_error($ch);
		}
		curl_close($ch);
		
		return json_decode($result, true)['access_token'];
	}
}

$kc = new KeycloakApiClient('12345678-90ab-cdef-1234-567890abcdef', 'https://login.mydomain.com');

// This works
$result = $kc->get('auth/realms/master');
echo print_r($result, true) . "\n";

// This does not
$result = $kc->get('auth/realms/master/clients');
echo print_r($result, true) . "\n";