From 771de550a59e826a903feadf4dd72be9bdef8a36 Mon Sep 17 00:00:00 2001
From: Meezaan-ud-Din A Wal-Ikram <m@meezaan.net>
Date: Tue, 7 Jan 2025 14:18:28 +0400
Subject: [PATCH] Add prometheus exporter and scrape metrics

---
 .k8s/manifest.yml        |  6 ++++++
 Dockerfile               |  2 +-
 README.md                |  2 +-
 docker-compose.yml       |  1 +
 etc/unit/.unit.conf.json | 29 +++++++++++++++++++++++++++--
 metrics/metrics.php      | 27 +++++++++++++++++++++++++++
 6 files changed, 63 insertions(+), 4 deletions(-)
 create mode 100644 metrics/metrics.php

diff --git a/.k8s/manifest.yml b/.k8s/manifest.yml
index 5b4007e..85ad497 100644
--- a/.k8s/manifest.yml
+++ b/.k8s/manifest.yml
@@ -115,6 +115,10 @@ spec:
       app: alquran-cloud-api
   template:
     metadata:
+      annotations:
+        prometheus.io/scrape: "true"
+        prometheus.io/port: "9090"
+        prometheus.io/path: "/metrics"
       labels:
         app: alquran-cloud-api
     spec:
@@ -181,6 +185,8 @@ spec:
           ports:
             - containerPort: 8080
               protocol: TCP
+            - containerPort: 9090
+              protocol: TCP
 ---
 # HPA
 apiVersion: autoscaling/v1
diff --git a/Dockerfile b/Dockerfile
index b86d4ad..a2613c8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM islamicnetwork/php:8.2-unit
+FROM islamicnetwork/php:8.3-unit
 
 # Copy files
 COPY . /var/www/
diff --git a/README.md b/README.md
index 173de8d..f7a29f4 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@
 This repository powers the AlQuran.cloud API on http://api.alquran.cloud.
 
 # Technology Stack
-* PHP 8.2
+* PHP 8.3
 * MySQL 8
 * Memcached 1.6
 * Kipchak API Development Kit (https://github.com/mam-luk/kipchak)
diff --git a/docker-compose.yml b/docker-compose.yml
index 24c1fba..7febe22 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -13,6 +13,7 @@ services:
       - alquran_api.env
     ports:
       - "80:8080"
+      - "9090:9090"
     volumes:
       - .:/var/www
     privileged: true
diff --git a/etc/unit/.unit.conf.json b/etc/unit/.unit.conf.json
index 2e18040..ddca675 100644
--- a/etc/unit/.unit.conf.json
+++ b/etc/unit/.unit.conf.json
@@ -7,10 +7,13 @@
   "listeners": {
     "*:8080": {
       "pass": "routes/main"
+    },
+    "*:9090": {
+      "pass": "routes/metrics"
     }
   },
   "applications": {
-    "api.alquran.cloud": {
+    "api_alquran_cloud": {
       "type": "php",
       "user": "nobody",
       "limits": {
@@ -25,9 +28,31 @@
       "root": "/var/www/html",
       "index": "index.php",
       "script": "index.php"
+    },
+    "metrics": {
+      "type": "php",
+      "root": "/var/www/metrics",
+      "index": "metrics.php",
+      "script": "metrics.php",
+      "user": "root",
+      "environment": {
+        "control_socket": "/var/run/control.unit.sock"
+      }
     }
   },
   "routes": {
+    "metrics": [
+      {
+        "match": {
+          "uri": [
+            "/metrics"
+          ]
+        },
+        "action": {
+          "pass": "applications/metrics"
+        }
+      }
+    ],
     "main": [
       {
         "match": {
@@ -55,7 +80,7 @@
           "uri": "*"
         },
         "action": {
-          "pass": "applications/api.alquran.cloud"
+          "pass": "applications/api_alquran_cloud"
         }
       }
     ]
diff --git a/metrics/metrics.php b/metrics/metrics.php
new file mode 100644
index 0000000..937f4fe
--- /dev/null
+++ b/metrics/metrics.php
@@ -0,0 +1,27 @@
+<?php
+
+$sock = stream_socket_client("unix://".getenv("control_socket"), $errno, $errst);
+fwrite($sock, "GET /status HTTP/1.0\r\n\r\n");
+$resp = fread($sock, 4096);
+fclose($sock);
+
+list($headers, $body) = explode("\r\n\r\n", $resp, 2);
+$json = json_decode($body);
+
+$metrics = array();
+array_push($metrics, "unit_connections_accepted_total ".$json->connections->accepted);
+array_push($metrics, "unit_connections_active ".$json->connections->active);
+array_push($metrics, "unit_connections_idle ".$json->connections->idle);
+array_push($metrics, "unit_connections_closed_total ".$json->connections->closed);
+array_push($metrics, "unit_requests_total ".$json->requests->total);
+
+foreach($json->applications as $application => $data) {
+    array_push($metrics, "unit_application_".$application."_processes_running ".$data->processes->running);
+    array_push($metrics, "unit_application_".$application."_processes_starting ".$data->processes->starting);
+    array_push($metrics, "unit_application_".$application."_processes_idle ".$data->processes->idle);
+    array_push($metrics, "unit_application_".$application."_requests_active ".$data->requests->active);
+}
+
+header("Content-Type: text/plain");
+echo join("\n", $metrics)."\n";
+?>
\ No newline at end of file