fix: add pre-sync database host connectivity check

Author: konradmichalik

deployer/feature/task/feature_sync.php

@@ -5,6 +5,54 @@
 require_once('feature_init.php');
 
 
+/**
+ * Verifies that the database host is reachable from the remote server before syncing.
+ * This is necessary because DNS for newly created databases (e.g. Mittwald) can be
+ * intermittent, and the time between feature:setup and feature:sync may cause DNS flapping.
+ */
+function waitForDatabaseHost(): void
+{
+    if (!has('database_host')
+        || '127.0.0.1' === get('database_host')
+        || 'localhost' === get('database_host')
+    ) {
+        return;
+    }
+
+    $hostname = get('database_host');
+    $port = (int) get('database_port', 3306);
+    $waitingTime = (int) get('mittwald_database_wait', 30);
+    $maxRetries = (int) get('mittwald_database_retries', 20);
+
+    while ($maxRetries > 0) {
+        try {
+            info("Verifying database host {$hostname}:{$port} before sync, remaining attempts: {$maxRetries}");
+            $check = sprintf(
+                'echo @fsockopen("%s", %d, $errno, $errstr, 5) ? "1" : "";',
+                $hostname,
+                $port
+            );
+            $result = run("php -r " . escapeshellarg($check));
+            if ('1' === trim($result)) {
+                info("Database host {$hostname}:{$port} is reachable.");
+                return;
+            }
+        } catch (\Throwable $e) {
+            debug("Pre-sync connectivity check failed: " . $e->getMessage());
+        }
+
+        if ($maxRetries > 1) {
+            sleep($waitingTime);
+        }
+        $maxRetries--;
+    }
+
+    throw new \RuntimeException(
+        "Database host {$hostname}:{$port} is not reachable before sync after all attempts."
+    );
+}
+
+
 task('feature:sync', function () {
 
     if ((has('feature_setup') && !get('feature_setup')) || !input()->getOption('feature')) return;
@@ -13,6 +61,8 @@
     $synced = false;
     $optionalVerbose = isVerbose() ? '-v' : '';
 
+    waitForDatabaseHost();
+
     /*
      * db_sync_tool
      * https://github.com/jackd248/db-sync-tool