Logowanie i monitoring w aplikacji webowej

[2024-01-15 10:30:45] [INFO] [auth-service] User login successful
  - user_id: 123
  - ip: 192.168.1.100
  - method: password

+-------------+     +-------------+     +-------------+
| Aplikacja   | --> |   Logi      | --> |  Analiza    |
| (zdarzenia) |     | (pliki/db)  |     | (narzedzia) |
+-------------+     +-------------+     +-------------+
      |                   |                   |
      v                   v                   v
  [Kod PHP]         [error.log]         [Kibana/Grafana]

       FATAL  [###] Aplikacja nie działa
         |
       ERROR  [###] Cos poszło nie tak
         |
        WARN  [###] Może być problem
         |
        INFO  [###] Normalne działanie
         |
       DEBUG  [###] Szczegóły techniczne

ZLE:
"Error occurred"
"User logged in"
"Password: secret123"

DOBRZE:
"[2024-01-15 10:30:45] [ERROR] [payment] Payment failed - user_id: 123,
  reason: insufficient_funds, amount: 99.99"
"[2024-01-15 10:30:45] [INFO] [auth] Login successful - user_id: 123,
  ip: 192.168.1.100"

<?php
// Podstawowe logowanie do pliku
function logMessage($level, $message, $context = []) {
    $timestamp = date('Y-m-d H:i:s');
    $contextStr = !empty($context) ? json_encode($context) : '';
    $logLine = "[$timestamp] [$level] $message $contextStr\n";

    error_log($logLine, 3, '/var/log/app/application.log');
}

// Użycie
logMessage('INFO', 'User logged in', ['user_id' => 123, 'ip' => $_SERVER['REMOTE_ADDR']]);
logMessage('ERROR', 'Database connection failed', ['error' => $e->getMessage()]);

<?php
class Logger {
    const DEBUG = 0;
    const INFO = 1;
    const WARN = 2;
    const ERROR = 3;

    private $minLevel = self::INFO;

    public function debug($message, $context = []) {
        $this->log(self::DEBUG, 'DEBUG', $message, $context);
    }

    public function info($message, $context = []) {
        $this->log(self::INFO, 'INFO', $message, $context);
    }

    public function warn($message, $context = []) {
        $this->log(self::WARN, 'WARN', $message, $context);
    }

    public function error($message, $context = []) {
        $this->log(self::ERROR, 'ERROR', $message, $context);
    }

    private function log($level, $levelName, $message, $context) {
        if ($level >= $this->minLevel) {
            $timestamp = date('Y-m-d H:i:s');
            $contextJson = json_encode($context);
            echo "[$timestamp] [$levelName] $message $contextJson\n";
        }
    }
}

<?php
// Logowanie proby logowania
function logLoginAttempt($username, $success, $ip) {
    $status = $success ? 'SUCCESS' : 'FAILED';
    $level = $success ? 'INFO' : 'WARN';

    logMessage($level, "Login attempt $status", [
        'username' => $username,  // OK - nazwa użytkownika
        'ip' => $ip,
        'user_agent' => $_SERVER['HTTP_USER_AGENT']
        // NIE logujemy hasła!
    ]);
}

// Logowanie podejrzanej aktywnosci
function logSuspiciousActivity($userId, $reason) {
    logMessage('WARN', 'Suspicious activity detected', [
        'user_id' => $userId,
        'reason' => $reason,
        'ip' => $_SERVER['REMOTE_ADDR'],
        'timestamp' => time()
    ]);
}

<?php
function logJson($level, $event, $data = []) {
    $log = [
        'timestamp' => date('c'),  // ISO 8601
        'level' => $level,
        'event' => $event,
        'service' => 'web-app',
        'data' => $data,
        'request_id' => $_SERVER['HTTP_X_REQUEST_ID'] ?? uniqid()
    ];

    file_put_contents(
        '/var/log/app/app.json.log',
        json_encode($log) . "\n",
        FILE_APPEND
    );
}

// Wynik:
// {"timestamp":"2024-01-15T10:30:45+00:00","level":"INFO",
//  "event":"user.login","service":"web-app",
//  "data":{"user_id":123},"request_id":"abc123"}