Debug elastcisearch8 connection

Author: djadobe16

app/code/Magento/Elasticsearch/Setup/Validator.php

@@ -38,11 +38,15 @@ public function validate(): array
         $errors = [];
         try {
             echo "Check elasticsearch8 server up or not with command line\n";
-            shell_exec("curl localhost:9200/");
+            shell_exec("curl http://127.0.0.1:9200/");
 
             $output = shell_exec('netstat -tuln');
             echo "<pre>$output</pre>";
 
+
+            $output = shell_exec("cat /var/log/elasticsearch/elasticsearch.log");
+            echo "<pre>$output</pre>";
+
             $client = $this->clientResolver->create();
             if (!$client->testConnection()) {
                 $errors[] = 'Could not validate a connection to Elasticsearch.'