aol-logger

A lightweight, enterprise-ready logger. Supports structured logs for both application and audit events, and integrates smoothly with PM2 + ELK stack environments.

📦 Installation

npm install aol-logger

🚀 Getting Started

Step 1: Initialize the Logger

In your service, create a logger.ts file to initialize and export the loggers:

// logger.ts
import { initLogger } from "aol-logger";

export const { logger, auditLogger } = initLogger("bx-be", "info");

Parameters:

• service_name: Name of the service (bx-be, caps-be, etc.)
• minLogLevel: Log level threshold (debug, info, warn, error)

📘 Usage

Import and use the logger and auditLogger as shown below:

// someService.ts
import { logger, auditLogger } from "./logger";

// General logs
logger.debug("Debugging mode active");
logger.info("User fetched successfully");
logger.warn("Disk space running low");
logger.error("Database connection failed");

// Audit logs
auditLogger.info("audit log", {
  user_id: 1,
  event_action: "create",
  event_type: "course",
  event_id: 123,
  location_id: 1 
});

🔍 Audit Log Fields Explained

Audit logs are critical for maintaining traceability of important actions in your system. Here's what each field means in the auditLogger payload:

🧑 user_id

• Type: number | string
• Description: Unique identifier of the user who performed the action.
• Purpose: Allows identifying which user is responsible for an operation.

🛠️ event_action

• Type: string
• Examples: "create", "update", "delete", "view", "login", "logout"
• Description: Describes the type of action performed.
• Purpose: Classifies the user’s operation for better auditing.

🧱 event_type

• Type: string
• Examples: "course", "user", "payment", "settings"
• Description: The domain/entity that the action is related to.
• Purpose: Helps segment audit logs by entity or feature.

🆔 event_id

• Type: number | string
• Description: Identifier of the affected entity (e.g., course ID).
• Purpose: Gives context about the specific resource involved in the action.

🆔 location_id

• Type: number | string
• Description: Identifier for the location, tenant, or region where the action occurred.
• Purpose: Useful for filtering logs in multi-tenant or multi-region applications.
• Examples: In PF, use tenant_id, In TPTM, use region_id

✅ Example

auditLogger.info("audit log", {
  user_id: 1,
  event_action: "create",
  event_type: "course",
  event_id: 123,
  location_id: 1 
});

📘 This means: "User 1 has created a course in location-1 with ID 123."

🔐 Best Practices

• Initialize logger and auditLogger once per service.
• Use audit logs for all critical operations that affect user data or system state.
• Set minLogLevel using environment variables for different environments (dev, staging, prod).

🛠️ Supported Environments

• Node.js (Express, NestJS, etc.)
• Deno (via compatibility layer)
• Compatible with PM2, Docker, ELK, and more

📄 License

MIT © Art of Living Digital