new PHP ratings service

.env

@@ -1,3 +1,3 @@
 # environment file for docker-compose
 REPO=robotshop
-TAG=0.2.9
+TAG=php

docker-compose.yaml

@@ -65,8 +65,8 @@ services:
         condition: on-failure
   mysql:
     build:
-      context: shipping/database
-    image: ${REPO}/rs-shipping-db:${TAG}
+      context: mysql
+    image: ${REPO}/rs-mysql-db:${TAG}
     networks:
       - robot-shop
     deploy:
@@ -75,7 +75,7 @@ services:
         condition: on-failure
   shipping:
     build:
-      context: shipping/service
+      context: shipping
     image: ${REPO}/rs-shipping:${TAG}
     depends_on:
       - mysql
@@ -85,6 +85,18 @@ services:
       replicas: 1
       restart_policy:
         condition: on-failure
+  ratings:
+    build:
+      context: ratings
+    image: ${REPO}/rs-ratings:${TAG}
+    networks:
+      - robot-shop
+    depends_on:
+      - mysql
+    deploy:
+      replicas: 1
+      restart_policy:
+        condition: on-failure
   payment:
     build:
       context: payment

load-gen/robot-shop.py

@@ -1,5 +1,6 @@
 from locust import HttpLocust, TaskSet, task
 from random import choice
+from random import randint
 
 class UserBehavior(TaskSet):
     def on_start(self):
@@ -33,7 +34,12 @@ def load(self):
                 if item['instock'] != 0:
                     break
 
+            # vote for item
+            if randint(1, 10) <= 3:
+                self.client.put('/api/ratings/api/rate/{}/{}'.format(item['sku'], randint(1, 5)))
+
             self.client.get('/api/catalogue/product/{}'.format(item['sku']))
+            self.client.get('/api/ratings/api/fetch/{}'.format(item['sku']))
             self.client.get('/api/cart/add/{}/{}/1'.format(uniqueid, item['sku']))
 
         cart = self.client.get('/api/cart/cart/{}'.format(uniqueid)).json()

mysql/scripts/20-ratings.sql

@@ -0,0 +1,16 @@
+CREATE DATABASE ratings
+DEFAULT CHARACTER SET 'utf8';
+
+USE ratings;
+
+CREATE TABLE ratings (
+    sku varchar(80) NOT NULL,
+    avg_rating DECIMAL(3, 2) NOT NULL,
+    rating_count INT NOT NULL,
+    PRIMARY KEY (sku)
+) ENGINE=InnoDB;
+
+
+GRANT ALL ON ratings.* TO 'ratings'@'%'
+IDENTIFIED BY 'iloveit';
+

ratings/Dockerfile

@@ -0,0 +1,14 @@
+FROM php:7.2-apache
+
+RUN docker-php-ext-install pdo_mysql
+
+# relax permissions on status
+COPY status.conf /etc/apache2/mods-available/status.conf
+# Enable Apache mod_rewrite and status
+RUN a2enmod rewrite && a2enmod status
+
+
+WORKDIR /var/www/html
+
+COPY html/ /var/www/html
+

ratings/html/.htaccess

@@ -0,0 +1,6 @@
+<IfModule mod_rewrite.c>
+    RewriteEngine On
+    RewriteCond %{REQUEST_FILENAME} !-f
+    RewriteCond %{REQUEST_FILENAME} !-d
+    RewriteRule api/(.*)$ api.php?request=$1 [QSA,NC,L]
+</IfModule>

ratings/html/API.class.php

@@ -0,0 +1,94 @@
+<?php
+abstract class API {
+    protected $method = '';
+
+    protected $endpoint = '';
+
+    protected $verb = '';
+
+    protected $args = array();
+
+    protected $file = Null;
+
+    public function __construct($request) {
+        // CORS
+        header('Access-Control-Allow-Origin: *');
+        header('Access-Control-Allow-Methods: *');
+        header('Content-Type: application/json');
+
+        $this->args = explode('/', rtrim($request, '/'));
+        $this->endpoint = array_shift($this->args);
+
+        if(array_key_exists(0, $this->args) && !is_numeric($this->args[0])) {
+            $this->verb = array_shift($this->args);
+        }
+
+        $this->method = $_SERVER['REQUEST_METHOD'];
+        if($this->method == 'POST' && array_key_exists('HTTP_X_METHOD', $_SERVER)) {
+            if($_SERVER['HTTP_X_HTTP_METHOD'] == 'DELETE') {
+                $this->method = 'DELETE';
+            } else if($_SERVER['HTTP_X_HTTP_METHOD'] == 'PUT') {
+                $this->method = 'PUT';
+            } else {
+                throw new Exception('Unexpected header');
+            }
+        }
+
+        switch($this->method) {
+        case 'DELETE':
+        case 'POST':
+            $this->request = $this->_cleanInputs($_POST);
+            break;
+        case 'GET':
+            $this->request = $this->_cleanInputs($_GET);
+            break;
+        case 'PUT':
+            $this->request = $this->_cleanInputs($_GET);
+            $this->file = file_get_contents('php://input');
+            break;
+        }
+    }
+
+    public function processAPI() {
+        if(method_exists($this, $this->endpoint)) {
+            try {
+                $result = $this->{$this->endpoint}();
+                return $this->_response($result, 200);
+            } catch (Exception $e) {
+                return $this->_response($e->getMessage(), $e->getCode());
+            }
+        }
+        return $this->_response("No endpoint: $this->endpoint", 404);
+    }
+
+    private function _response($data, $status = 200) {
+        header('HTTP/1.1 ' . $status . ' ' . $this->_requestStatus($status));
+        return json_encode($data);
+    }
+
+    private function _cleanInputs($data) {
+        $clean_input = array();
+
+        if(is_array($data)) {
+            foreach($data as $k => $v) {
+                $clean_input[$k] = $this->_cleanInputs($v);
+            }
+        } else {
+            $clean_input = trim(strip_tags($data));
+        }
+
+        return $clean_input;
+    }
+
+    private function _requestStatus($code) {
+        $status = array(
+            200 => 'OK',
+            400 => 'Bad Request',
+            404 => 'Not Found',
+            405 => 'Method Not Allowed',
+            500 => 'Internal Server Error');
+
+        return (array_key_exists("$code", $status) ? $status["$code"] : $status['500']);
+    }
+}
+?>

ratings/html/api.php

@@ -0,0 +1,161 @@
+<?php
+require_once 'API.class.php';
+
+class RatingsAPI extends API {
+    public function __construct($request, $origin) {
+        parent::__construct($request);
+    }
+
+    protected function health() {
+        return 'OK';
+    }
+
+    protected function dump() {
+        $data = array();
+        $data['method'] = $this->method;
+        $data['verb'] = $this->verb;
+        $data = array_merge($data, array('args' => $this->args));
+
+        return $data;
+    }
+
+    // ratings/fetch/sku
+    protected function fetch() {
+        if($this->method == 'GET' && isset($this->verb) && count($this->args) == 0) {
+            $sku = $this->verb;
+            $data = $this->_getRating($sku);
+            return $data;
+        } else {
+            throw new Exception('Bad request', 400);
+        }
+    }
+
+    // ratings/rate/sku/score
+    protected function rate() {
+        if($this->method == 'PUT' && isset($this->verb) && count($this->args) == 1) {
+            $sku = $this->verb;
+            $score = intval($this->args[0]);
+            $score = min(max(1, $score), 5);
+
+            if(! $this->_checkSku($sku)) {
+                throw new Exception("$sku not found", 404);
+            }
+
+            $rating = $this->_getRating($sku);
+            if($rating['avg_rating'] == 0) {
+                // not rated yet
+                $this->_insertRating($sku, $score);
+            } else {
+                // iffy maths
+                $newAvg = (($rating['avg_rating'] * $rating['rating_count']) + $score) / ($rating['rating_count'] + 1);
+                $this->_updateRating($sku, $newAvg, $rating['rating_count'] + 1);
+            }
+        } else {
+            throw new Exception('Bad request', 400);
+        }
+
+        return 'OK';
+    }
+
+    private function _getRating($sku) {
+        $db = $this->_dbConnect();
+        if($db) {
+            $stmt = $db->prepare('select avg_rating, rating_count from ratings where sku = ?');
+            if($stmt->execute(array($sku))) {
+                $data = $stmt->fetch();
+                if($data) {
+                    // for some reason avg_rating is return as a string
+                    $data['avg_rating'] = floatval($data['avg_rating']);
+                    return $data;
+                } else {
+                    // nicer to return an empty record than throw 404
+                    return array('avg_rating' => 0, 'rating_count' => 0);
+                }
+            } else {
+                throw new Exception('Failed to query data', 500);
+            }
+        } else {
+            throw new Exception('Database connection error', 500);
+        }
+    }
+
+    private function _updateRating($sku, $score, $count) {
+        $db = $this->_dbConnect();
+        if($db) {
+            $stmt = $db->prepare('update ratings set avg_rating = ?, rating_count = ? where sku = ?');
+            if(! $stmt->execute(array($score, $count, $sku))) {
+                throw new Exception('Failed to update data', 500);
+            }
+        } else {
+            throw new Exception('Database connection error', 500);
+        }
+    }
+
+    private function _insertRating($sku, $score) {
+        $db = $this->_dbConnect();
+        if($db) {
+            $stmt = $db->prepare('insert into ratings(sku, avg_rating, rating_count) values(?, ?, ?)');
+            if(! $stmt->execute(array($sku, $score, 1))) {
+                throw new Exception('Failed to insert data', 500);
+            }
+        } else {
+            throw new Exception('Database connection error', 500);
+        }
+    }
+
+    private function _dbConnect() {
+        $dsn = getenv('PDO_URL') ? getenv('PDO_URL') : 'mysql:host=mysql;dbname=ratings;charset=utf8mb4';
+        $opt = array(
+            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+            PDO::ATTR_EMULATE_PREPARES => false
+        );
+
+        $db = false;
+        try {
+            $db = new PDO($dsn, 'ratings', 'iloveit', $opt);
+        } catch (PDOException $e) {
+            $msg = $e->getMessage();
+            error_log("Database error $msg");
+            $db = false;
+        }
+
+        return $db;
+    }
+
+    // check sku exists in product catalogue
+    private function _checkSku($sku) {
+        $url = getenv('CATALOGUE_URL') ? getenv('CATALOGUE_URL') : 'http://catalogue:8080/';
+        $url = $url . 'product/' . $sku;
+
+        $opt = array(
+            CURLOPT_RETURNTRANSFER => true,
+        );
+        $curl = curl_init($url);
+        curl_setopt_array($curl, $opt);
+
+        $data = curl_exec($curl);
+        if(! $data) {
+            throw new Exception('Failed to connect to catalogue', 500);
+        }
+        $status = curl_getinfo($curl, CURLINFO_RESPONSE_CODE);
+        error_log("catalogue status $status");
+
+        curl_close($curl);
+
+        return $status == 200;
+
+    }
+}
+
+if(!array_key_exists('HTTP_ORIGIN', $_SERVER)) {
+    $_SERVER['HTTP_ORIGIN'] = $_SERVER['SERVER_NAME'];
+}
+
+try {
+    $API = new RatingsAPI($_REQUEST['request'], $_SERVER['HTTP_ORIGIN']);
+    echo $API->processAPI();
+} catch(Exception $e) {
+    echo json_encode(Array('error' => $e->getMessage()));
+}
+?>

ratings/html/info.php

@@ -0,0 +1 @@
+<?php phpinfo(); ?>

ratings/status.conf

@@ -0,0 +1,29 @@
+<IfModule mod_status.c>
+	# Allow server status reports generated by mod_status,
+	# with the URL of http://servername/server-status
+	# Uncomment and change the "192.0.2.0/24" to allow access from other hosts.
+
+	<Location /server-status>
+		SetHandler server-status
+		#Require local
+		#Require ip 192.0.2.0/24
+	</Location>
+
+	# Keep track of extended status information for each request
+	ExtendedStatus On
+
+	# Determine if mod_status displays the first 63 characters of a request or
+	# the last 63, assuming the request itself is greater than 63 chars.
+	# Default: Off
+	#SeeRequestTail On
+
+
+	<IfModule mod_proxy.c>
+		# Show Proxy LoadBalancer status in mod_status
+		ProxyStatus On
+	</IfModule>
+
+
+</IfModule>
+
+# vim: syntax=apache ts=4 sw=4 sts=4 sr noet