Misc Improvements for gitlab webhook

.htaccess

@@ -0,0 +1,3 @@
+<Files "config.yml">
+    Require all denied
+</Files>

webhook.php

@@ -4,20 +4,37 @@
 use Symfony\Component\Process\Process;
 use Symfony\Component\Yaml\Yaml;
 
+header('Content-Type: text/html; charset=utf-8');
+
 if (!file_exists(__DIR__.'/config.yml')) {
     echo "Please, define your satis configuration in a config.yml file.\nYou can use the config.yml.dist as a template.";
     exit(-1);
 }
 
 $defaults = array(
     'bin' => 'bin/satis',
+    'options' => '',
     'json' => 'satis.json',
     'webroot' => 'web/',
     'user' => null,
+    'token' => null,
 );
 $config = Yaml::parse(__DIR__.'/config.yml');
 $config = array_merge($defaults, $config);
 
+if ($config['token']) {
+    if (!isset($_SERVER['HTTP_X_GITLAB_TOKEN']) || $_SERVER['HTTP_X_GITLAB_TOKEN'] != $config['token']) {
+        header("{$_SERVER['SERVER_PROTOCOL']} 403 Forbidden", true, 403);
+        exit(1);
+    }
+}
+
+$repositoryUrl = null;
+$gitData = Yaml::parse(file_get_contents('php://input'));
+if (is_array($gitData) && isset($gitData['project'], $gitData['project']['git_ssh_url'])) {
+    $repositoryUrl = $gitData['project']['git_ssh_url'];
+}
+
 $errors = array();
 if (!file_exists($config['bin'])) {
     $errors[] = 'The Satis bin could not be found.';
@@ -32,26 +49,85 @@
 }
 
 if (!empty($errors)) {
+    header("{$_SERVER['SERVER_PROTOCOL']} 500 Internal Server Error", true, 500);
     echo 'The build cannot be run due to some errors. Please, review them and check your config.yml:'."\n";
     foreach ($errors as $error) {
         echo '- '.$error."\n";
     }
     exit(-1);
 }
 
-$command = sprintf('%s build %s %s', $config['bin'], $config['json'], $config['webroot']);
+$command = sprintf('%s %s build %s %s', $config['bin'], $config['options'], $config['json'], $config['webroot']);
 if (null !== $config['user']) {
     $command = sprintf('sudo -u %s -i %s', $config['user'], $command);
 }
 
-$process = new Process($command);
-$exitCode = $process->run(function ($type, $buffer) {
-    if ('err' === $type) {
-        echo 'E';
-        error_log($buffer);
-    } else {
-        echo '.';
-    }
-});
+if (null !== $repositoryUrl) {
+    $command .= ' --repository-url=' . escapeshellarg($repositoryUrl);
+}
 
-echo "\n\n" . ($exitCode === 0 ? 'Successful rebuild!' : 'Oops! An error occured!') . "\n";
+function execute_build() {
+    global $command, $config;
+    do {
+        $lock_process = fopen($process_file = __DIR__.'/process.lock', "w");
+        if (!flock($lock_process, LOCK_EX | LOCK_NB)) {
+            $lock_wait = fopen($wait_file = __DIR__.'/wait.lock', 'w');
+            if (!flock($lock_wait, LOCK_EX | LOCK_NB)) {
+                fclose($lock_wait);
+                fclose($lock_process);
+                echo "There is already a build-process waiting. Skipping.";
+                return;
+            }
+            echo "There is already a build-process running. Waiting...";
+            if (!flock($lock_process, LOCK_EX)) { // wait
+                echo 'E: Failed to aquire lock';
+                exit(1);
+            }
+            flock($lock_wait, LOCK_UN);
+            unlink($wait_file); 
+            fclose($lock_wait);
+
+            flock($lock_process, LOCK_UN);
+            fclose($lock_process);
+            $lock_process = null;
+        }
+    } while (!$lock_process);
+    fwrite($lock_process, getmypid());
+    $process = new Process($command);
+    if (isset($config['env']))
+        $process->setEnv($config['env']);
+
+    $exitCode = $process->run(function ($type, $buffer) {
+        if ('err' === $type) {
+            echo 'E: ', $buffer, PHP_EOL;
+            error_log($buffer);
+        } else {
+            echo '.';
+        }
+    });
+
+    flock($lock_process, LOCK_UN);
+    unlink($process_file);
+    fclose($lock_process);
+
+    echo "\n\n" . ($exitCode === 0 ? 'Successful rebuild!' : 'Oops! An error occured!') . "\n";
+}
+
+if (!empty($_SERVER['HTTP_X_GITLAB_EVENT'])) {
+    // Responde as quick as possible
+    ini_set('implicit_flush', true);
+    ignore_user_abort(true);
+    header("Connection: close", true);
+    header("Content-Length: 2", true);
+    ob_end_flush();
+    //register_shutdown_function("execute_build");
+    if (function_exists('fastcgi_finish_request'))
+        fastcgi_finish_request();
+    echo "ok";
+    flush();
+    echo str_pad("", 64*1024);flush();
+    execute_build();
+    exit(0);
+} else {
+    execute_build();
+}