Added healthcheck to image that pings the ws server

Dockerfile

@@ -12,4 +12,7 @@ USER 82
 
 ENTRYPOINT ["php", "/app/server.php"]
 
+HEALTHCHECK --interval=20s --timeout=1s --start-period=5s \
+  CMD php /app/healthcheck.php
+
 COPY --from=composer /app /app

composer.json

@@ -1,11 +1,18 @@
 {
     "require": {
-        "cboden/ratchet": "dev-php82"
+        "cboden/ratchet": "dev-php82",
+        "ratchet/pawl": "^0.4.1"
     },
     "repositories": [
       {
         "type": "vcs",
         "url": "https://github.com/josh-gaby/Ratchet"
       }
-    ]
+    ],
+    "replace": {
+        "symfony/polyfill-mbstring": "*",
+        "symfony/polyfill-php82": "*",
+        "symfony/polyfill-php81": "*",
+        "symfony/polyfill-php80": "*"
+     }
 }

healthcheck.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App;
+
+require __DIR__.'/vendor/autoload.php';
+
+\Ratchet\Client\connect('ws://localhost:8089')->then(function($conn) {
+   $conn->send('ping');
+   $conn->close();
+}, function ($e) {
+    echo "Could not connect:\n{$e->getMessage()}\n";
+    exit(1);
+});

server.php

@@ -31,16 +31,19 @@ public function onOpen(ConnectionInterface $conn): void
 
     public function onMessage(ConnectionInterface $from, $msg): void
     {
-        /**
-         * @var \Ratchet\WebSocket\WsConnection $from
-         */
-        $numRecv = count($this->clients) - 1;
-        echo sprintf(
-            'Sending message "%s" to %d other connection%s' . "\n",
-            $msg,
-            $numRecv,
-            $numRecv == 1 ? '' : 's'
-        );
+        // Don't log output if ping message
+        if ('ping' !== $msg) {
+            /**
+             * @var \Ratchet\WebSocket\WsConnection $from
+             */
+            $numRecv = count($this->clients) - 1;
+            echo sprintf(
+                'Sending message "%s" to %d other connection%s' . "\n",
+                $msg,
+                $numRecv,
+                $numRecv == 1 ? '' : 's'
+            );
+        }
 
         foreach ($this->clients as $client) {
             if ($from !== $client) {
@@ -79,5 +82,5 @@ public function onError(ConnectionInterface $conn, \Exception $e): void
     $port
 );
 
-echo 'Initializing websocket server';
-$server->run();
+echo "Initializing websocket server";
+$server->run();