update_forge_server.php

<?php
/*
 * A utility file to update a minecraft server that gets its resources from a solder link.
 * Requires solder to respect the /:slug/:build:/server api request.
 * Can work without it, with some modifications.
*/

//$mcversion = "1.7.10";
//$forgeversion = "1.7.10-10.13.4.1492-1.7.10";

// wherever your solder exists
$endpoint = "http://solder.example.com/";
// modpack slug
$modpack = "best-mod-pack-ever";
// target latest? recommended? whatever comes back in the modpack json.
$target = "latest";
// where to install the files
$serverpath = "/path/to/install/server/files/to/";
// print status? a lot?
$verbosemode = true;

// data source strings
$mcservername = "minecraft_server.%s.jar";
$mcendpoint = "https://s3.amazonaws.com/Minecraft.Download/versions/%s/minecraft_server.%s.jar";
$forgeservername = "forge-%s-%s.jar";
$forgeendpoint = "http://files.minecraftforge.net/maven/net/minecraftforge/forge/%s/forge-%s-%s.jar";
$forgetarget = "installer";

function verbose_print($msg){
    global $verbosemode;
    if($verbosemode){
        print($msg);
    }
}

function verbose_print_r($msg){
    global $verbosemode;
    if($verbosemode){
        print_r($msg);
    }
}

function ensure_server_setup(){
    global $serverpath;
    if(!file_exists($serverpath."cache")){
        mkdir($serverpath."cache");
    }
}

function server_file_exists($path){
    global $serverpath;
    return file_exists($serverpath.$path);
}

function file_has_hash($file, $hash){
    return md5_file($file) == $hash;
}

function server_file_has_hash($file, $hash){
    global $serverpath;
    return file_has_hash($serverpath.$file, $hash);
}

function get_data($url) {
    $ch = curl_init();
    $timeout = 5;
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
    $data = curl_exec($ch);
    curl_close($ch);
    return $data;
}

function download_file($url, $output=""){
    $parts = explode("/", $url);
    $last = $parts[sizeof($parts)-1];
    if($output==""){
        $output = $last;
    }
    file_put_contents($output, fopen($url, 'r'));
    return $output;
}

function move_file_to_server($file, $location=""){
    global $serverpath;
    return rename($file, $serverpath.$location.$file);
}

function download_minecraft($version){
    global $mcendpoint, $mcservername;
    $file_to_get = 	sprintf($mcendpoint, $version, $version);
    $file_to_save = sprintf($mcservername, $version);

    return download_file($file_to_get, $file_to_save);
}

function download_forge($version, $target){
    global $forgeendpoint, $forgeservername;
    $file_to_get = sprintf($forgeendpoint, $version, $version, $target);
    $file_to_save = sprintf($forgeservername, $version, $target);

    return download_file($file_to_get, $file_to_save);
}

function get_endpoint($method){
    global $endpoint;
    return json_decode(get_data($endpoint.$method), true);
}

function get_files_to_download($modpack, $target){
    $data = get_endpoint("api/modpack/".$modpack);
    verbose_print_r($data);
    return get_endpoint("api/modpack/".$modpack."/".$data[$target]."/server");
}

function install_mod($modzip){
    global $serverpath;
    $zip = new ZipArchive;
    $res = $zip->open($serverpath.$modzip);
    if ($res === TRUE){
        $zip->extractTo($serverpath);
        $zip->close();
    } else {
        error_log("Couldn't install mod ".$modzip);
    }
}

function finalize_modpack($modpack, $target){
    global $serverpath;
    copy($serverpath."bin/modpack.jar", $serverpath.$modpack."-".$target.".jar");
}

function agree_to_eula(){
    global $serverpath;
    file_put_contents($serverpath."eula.txt", "eula=true");
}

function disagree_to_eula(){
    global $serverpath;
    file_put_contents($serverpath."eula.txt", "eula=false");
}

function verify_minecraft($version){
    global $mcservername;
    $file_to_verify = sprintf($mcservername, $version);
    if(!server_file_exists($file_to_verify)){
        verbose_print("downloading minecraft ".$file_to_verify);

        $server_file = download_minecraft($file_to_verify);
        move_file_to_server($server_file);
    }
}

function verify_forge($version){
    global $forgeservername;
    $file_to_verify = sprintf($forgeservername, $version, "installer");
    if(!server_file_exists($file_to_verify)){
        verbose_print("downloading minecraft ".$file_to_verify);

        $server_file = download_forge($version, "installer");
        move_file_to_server($server_file);
        return true;
    }
    return false;
}

function verify_mods($mods){
    foreach($mods as $mod){
        $cachepath = "cache/".$mod["name"]."-".$mod["version"].".zip";
        $file_exists = server_file_exists($cachepath);
        $file_has_hash = false;
        if($file_exists){
            $file_has_hash = server_file_has_hash($cachepath, $mod["md5"]);
        }

        // download the mod if it don't exist / hashes are wrong
        //@TODO: safely uninstall previous versions using previous version's zip structure
        //@TODO: keep the previous version/json response somewhere to uninstall the right mods
        if(!$file_exists || !$file_has_hash){
            verbose_print("downloading ".$cachepath);
            $modfile = download_file($mod["url"]);
            if(file_has_hash($modfile, $mod["md5"])){
                move_file_to_server($modfile, "cache/");
                // install mods
                install_mod($cachepath);
            }else{
                error_log("File ".$modfile." downloaded wrong.");
            }
        }
    }
}

function install_forge_server($version){
    global $serverpath, $forgeservername;
    $forge_jar = $serverpath.sprintf($forgeservername, $version, "install");
    exec("cd {$serverpath} && java -jar {$forge_jar} --installServer 2>&1", $results);
    verbose_print_r($results);
}

function build_modpack($modpack, $target){
    verbose_print("building ".$modpack." v".$target);
    $to_download = get_files_to_download($modpack, $target);

    // get the server jar & install it if it does not exist
    //verify_minecraft($to_download["minecraft"]);
    //if(verify_forge($to_download["forge"])){
    //    install_forge_server($to_download["forge"]);
    //}

    // get the mods
    verify_mods($to_download['mods']);

    // install forge to root of the server, presuming we got it from a modpack
    finalize_modpack($modpack, $target);
}

// process
ensure_server_setup();
build_modpack($modpack, $target);
// nothing says consent like automation
agree_to_eula();