Quick and dirty WP endpoint to redirect to a download of attached file for a latest GitHub release.

github-release-download.php

<?php
declare( strict_types=1 );

new class( 'Rarst', [ 'laps' ] ) {

	private $owner, $repos;

	private $endpoint = 'download';

	public function __construct( string $owner, array $repos ) {
		$this->owner = $owner;
		$this->repos = $repos;

		add_action( 'init', [ $this, 'init' ] );
	}

	public function init() {

		add_rewrite_endpoint( $this->endpoint, EP_ROOT );

		add_filter( 'posts_where', [ $this, 'posts_where' ], 10, 2 );
		add_filter( 'template_include', [ $this, 'template_include' ], 9 );
	}

	public function posts_where( $where, $query ) {

		if ( isset( $query->query[ $this->endpoint ] ) ) {
			return ' AND 1=0';
		}

		return $where;
	}

	public function template_include( $template ) {

		global $wp_query;

		$repo_name = $wp_query->query[ $this->endpoint ] ?? '';

		if ( ! in_array( $repo_name, $this->repos, true ) ) {
			return $template;
		}

		$transient_key = "latest-release-{$this->owner}/{$repo_name}";
		$api_url       = "https://api.github.com/repos/{$this->owner}/{$repo_name}/releases/latest";
		$release_url   = "https://github.com/{$this->owner}/{$repo_name}/releases/latest";
		$response      = get_transient( $transient_key );

		if ( empty( $response ) ) {
			$response = wp_remote_get( $api_url );
			$response = wp_remote_retrieve_body( $response );

			if ( empty( $response ) ) {
				wp_redirect( $release_url );
				die;
			}

			set_transient( $transient_key, $response, 15 * MINUTE_IN_SECONDS );
		}
		$response     = json_decode( $response );
		$redirect_url = $response->assets[0]->browser_download_url ?? $release_url;

		wp_redirect( $redirect_url );
		die;
	}
};

I don't quite follow the difference about what you are doing and how AWS is involved.

What my code is doing:

1. Making an API request to /repos/:owner/:repo/releases/latest e.g. https://api.github.com/repos/rarst/laps/releases/latest
2. Looking up first asset in it (I only have one usually) and browser_download_url in it, e.g. https://github.com/Rarst/laps/releases/download/2.0/laps-2.0.zip, which is where I want to send client.

Could you please elaborate what do you think could be simplified here?

The URL that leads to for the zipfile is https://github-production-release-asset-2e65be.s3.amazonaws.com/19918104/36284318-1ae2-11e8-8cab-c6bf9500cf02?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20181111%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181111T060155Z&X-Amz-Expires=300&X-Amz-Signature=1801293b227f02238cab73c5c839c473f33d48855e963fc85e290246c9e50644&X-Amz-SignedHeaders=host&actor_id=1296790&response-content-disposition=attachment%3B%20filename%3Dlaps-2.0.zip&response-content-type=application%2Foctet-stream

I was using that for updating from release assets but because of the X-Amz-Expires=300 I can only store it for 5 minutes(300 seconds).

If you only need to send a client the release asset URL and have them download from the browser you’re OK. I was downloading the zipfile in WP core for updating and needed the AWS link.

My mistake in thinking we were doing the same thing.