Self-Hosted WordPress Plugin Updates (Server Plugin)

self-hosted-plugin-updates-server.php

<?php

/*
Plugin Name: Self-Hosted WordPress Plugin Updates - Server
Description: Demo plugin showcasing a server which acts as a custom update server for other plugins.
Version: 1.0.0
Author: Drazen Bebic
Author URI: https://drazen.bebic.dev
Text Domain: shwpus
Domain Path: /languages
*/

/**
 * Registers the routes needed by the plugins.
 *
 * @return void
 */
function shwpus_register_routes() {
	register_rest_route(
		'shwpus/v1',
		'/version/(?P<plugin>[\w-]+)',
		array(
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => 'shwpus_handle_plugin_version_request',
				'permission_callback' => 'shwpus_handle_permission_callback',
				'args'                => array(
					'plugin' => array(
						'description' => 'The plugin slug, i.e. "my-plugin"',
						'type'        => 'string',
					),
				),
			),
		)
	);

	register_rest_route(
		'shwpus/v1',
		'/info/(?P<plugin>[\w-]+)',
		array(
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => 'shwpus_handle_plugin_info_request',
				'permission_callback' => 'shwpus_handle_permission_callback',
				'args'                => array(
					'plugin' => array(
						'description' => 'The plugin slug, i.e. "my-plugin"',
						'type'        => 'string',
					),
				),
			),
		)
	);

	register_rest_route(
		'shwpus/v1',
		'/package/(?P<plugin>[\w.-]+)',
		array(
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => 'shwpus_handle_plugin_package_request',
				'permission_callback' => 'shwpus_handle_permission_callback',
				'args'                => array(
					'plugin' => array(
						'description' => 'The plugin slug with the version, ending in .zip, i.e. "my-plugin.2.0.0.zip"',
						'type'        => 'string',
					),
				),
			),
		)
	);
}

add_action( 'rest_api_init', 'shwpus_register_routes' );

/**
 * @param WP_REST_Request $request
 *
 * @return true|WP_Error
 */
function shwpus_handle_permission_callback( $request ) {
	$slug = $request->get_param( 'plugin' );
	$license = $request->get_param( 'license' );

	if ( $license !== 'XXX-YYY-ZZZ' ) {
		return new WP_Error(
			401,
			'Invalid license',
			array(
				'slug' => $slug,
				'license' => $license
			)
		);
	}

	return true;
}

/**
 * Finds the latest version for a given plugin.
 *
 * @param WP_REST_Request $request
 *
 * @return void
 */
function shwpus_handle_plugin_version_request( $request ) {
	// Retrieve the plugin slug from the
	// request. Use this slug to find the
	// latest version of your plugin.
	$slug = $request->get_param( 'plugin' );

	// This is hardcoded for demo purposes.
	// Normally you would fetch this from
	// your database or whatever other
	// source of truth you have.
	$version = '1.0.1';

	header('Content-Type: text/html; charset=utf-8');
	http_response_code( 200 );
	echo $version;
	die();
}

/**
 * Fetches information about the latest version
 * of the plugin with the given slug.
 *
 * @param WP_REST_Request $request
 *
 * @return void
 */
function shwpus_handle_plugin_info_request( $request ) {
	$slug    = $request->get_param( 'plugin' );
	$version = '1.0.1';

	// This data should be fetched dynamically
	// but for demo purposes it is hardcoded.
	$info = new stdClass();
	$info->name = 'Self-Hosted WordPress Plugin Updates - Client';
	$info->slug = 'self-hosted-plugin-updates-client';
	$info->plugin_name = 'self-hosted-plugin-updates-client';
	$info->new_version = $version;
	$info->requires = '6.0';
	$info->tested = '6.5.3';
	$info->downloaded = 12540;
	$info->last_updated = '2024-05-23';
	$info->sections = array(
		'description' => '
			<h1>Self-Hosted WordPress Plugin Updates - Client</h1>
			<p>
				Demo plugin showcasing a client plugin
				which updates from a custom update
				server.
			</p>
		',
		'changelog' => '
			<h1>We did exactly 3 things!</h1>
			<p>
				You thought this is going to be a huge update.
				But it\'s not. Sad face.
			</p>
			<ul>
				<li>Added a cool new feature</li>
				<li>Added another cool new feature</li>
				<li>Fixed an old feature</li>
			</ul>
		',
		// You can add more sections this way.
		'new_tab' => '
			<h1>Woah!</h1>
			<p>We are so cool, we know how to add a new tab.</p>
		',
	);
	$info->url = 'https://drazen.bebic.dev';
	$info->download_link = get_rest_url( null, "/shwpus/v1/package/$slug.$version.zip" );

	header('Content-Type: text/html; charset=utf-8');
	http_response_code( 200 );
	echo serialize( $info );
	die();
}

/**
 * @param WP_REST_Request $request
 *
 * @return void
 */
function shwpus_handle_plugin_package_request( $request ) {
	// Contains the plugin name, version, and .zip
	// extension. Example:
	// self-hosted-plugin-updates-server.1.0.1.zip
	$plugin = $request->get_param( 'plugin' );

	// The packages are located in wp-content for
	// demo purposes.
	$file = WP_CONTENT_DIR . "/packages/$plugin";

	if ( ! file_exists( $file ) ) {
		header( 'Content-Type: text/plain' );
		http_response_code( 404 );
		echo "The file $file does not exist.";
		die();
	}

	$file_size = filesize( $file );

	header( 'Content-Type: application/octet-stream' );
	header( "Content-Length: $file_size" );
	header( "Content-Disposition: attachment; filename=\"$plugin\"" );
	header( 'Access-Control-Allow-Origin: *' );
	http_response_code( 200 );
	readfile( $file );
	die();
}