Healthcheck endpoint

app/Healthcheck.php

@@ -0,0 +1,48 @@
+<?php
+namespace App;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Config;
+use ORM;
+
+class Healthcheck {
+  const ERROR = 'ERROR';
+  const OK = 'OK';
+  const REDIS_SUCCESSFUL_PING = 'PONG';
+
+  public function index(ServerRequestInterface $request, ResponseInterface $response) {
+    $userlog = make_logger('healthcheck');
+
+    $services = [
+      'mysql' => self::ERROR,
+      'redis' => self::ERROR,
+    ];
+
+    // Redis
+    try {
+      if(redis()->ping() == self::REDIS_SUCCESSFUL_PING) {
+        $services['redis'] = self::OK;
+      }
+    } catch(\Predis\Connection\ConnectionException $e) {
+      $userlog->info(
+        'Redis connection healthcheck failure'
+      );
+    }
+
+    // MySQL
+    try {
+      ORM::raw_execute('SELECT version();');
+      $services['mysql'] = self::OK;
+    } catch(\Exception $e) {
+      $userlog->info(
+        'MySQL connection healthcheck failure'
+      );
+    }
+
+    // Always
+    $response->getBody()->write(json_encode($services));
+    return $response;
+  }
+}
+

lib/helpers.php

@@ -5,6 +5,8 @@
 use Monolog\Logger;
 use Monolog\Handler\StreamHandler;
 
+const LOCAL_FALLBACK_REDIS = 'tcp://127.0.0.1:6379';
+
 date_default_timezone_set('UTC');
 
 if(getenv('ENV')) {
@@ -61,10 +63,14 @@ function random_user_code() {
   return $code;
 }
 
+function get_redis_url() {
+  return $redisURL = getenv('REDIS_URL') ?? LOCAL_FALLBACK_REDIS;
+}
 function redis() {
   static $client = false;
-  if(!$client)
-    $client = new Predis\Client('tcp://127.0.0.1:6379');
+  if(!$client) {
+    $client = new Predis\Client(get_redis_url());
+  }
   return $client;
 }
 

public/index.php

@@ -24,7 +24,7 @@
 $route = new League\Route\RouteCollection($container);
 
 $route->map('GET', '/', 'App\\Controller::index');
-
+$route->map('GET', '/health', 'App\\Healthcheck::index');
 $route->map('GET', '/api', 'App\\Controller::api_docs');
 $route->map('GET', '/setup', 'App\\Controller::setup_docs');
 $route->map('GET', '/faq', 'App\\Controller::faq');