pino-transport-rotating

Pino Plugin - Rotating File Transport

This module provides a custom logging transport for the pino logger that uses rotating file streams to manage log files. It supports log file rotation based on size and time intervals, and it can be configured to include log file compression.

Features

• File Rotation: Rotates log files based on size and time intervals.
• Compression: Compresses rotated log files using gzip.
• Custom Filename: Allows customization of the log file name.
• Enable/Disable: Option to enable or disable logging.
• Size Limit: Configurable size limit for log file rotation.
• Interval: Configurable time interval for log file rotation.
• Compression Method: Configurable compression method for rotated log files.
• Immutability: Option to apply immutability to rotated log files.
• Event Handling: Emits a rotated event when a log file is rotated.

Usage

To use the plugin, import it and provide the required configuration options:

import path from "node:path";
import { pino, LoggerOptions } from "pino";

const loggerOptions: LoggerOptions = {
  name: "server start",
  level: "trace",
  transport: {
    targets: [
      {
        level: "info",
        target: "pino-pretty",
        options: {
          colorize: true,
        },
      },
      {
        level: "info",
        target: "pino-transport-rotating",
        options: {
          dir: path.join(process.cwd(), "logs"),
          filename: "all",
          enabled: true,
          size: "100K",
          interval: "1d",
          compress: true,
          immutable: true,
        },
      },
      {
        level: "error",
        target: "pino-transport-rotating",
        options: {
          dir: path.join(process.cwd(), "logs"),
          filename: "error",
          enabled: true,
          size: "100K",
          interval: "1d",
          compress: true,
          immutable: true,
        },
      },
    ],
  },
};

const logger = pino(loggerOptions);

logger.info("Server started");
logger.error("An error occurred");

Configuration Options

The plugin accepts the following options:

• dir (string, required): The directory where the log files will be saved.
• filename (string, optional): The base name of the log file. Defaults to 'app'.
• enabled (boolean, optional): If false, logging is disabled. Defaults to true.
• size (string, optional): The size at which to rotate the log files. Defaults to '100K'.
• interval (string, optional): The interval at which to rotate the log files. Defaults to '1d'.
• compress (boolean, optional): Whether to compress rotated files. Defaults to true.
• immutable (boolean, optional): Whether to apply immutability to the rotated files. Defaults to true.

Example Configuration

{
  dir: '/var/log/app',
  filename: 'app',
  enabled: true,
  size: '100K',
  interval: '1d',
  compress: true,
  immutable: true,
}

File Rotation

The log files are rotated based on the following parameters:

• Size: 100 KB (100K) - Log files are rotated when they reach 100 KB in size (configurable).
• Interval: 1 day (1d) - Log files are rotated daily (configurable).
• Compression: gzip - Rotated files are compressed using gzip (configurable).
• Filename Pattern: ${filename}-${timestamp}.log - The rotated files are named using the ${filename}-${timestamp}.log pattern.

Rotated Event

The plugin emits a rotated event whenever a log file is rotated. This event can be used to perform additional actions, such as compressing the rotated file. For example:

rotatingStream.on("rotated", async (rotatedFile) => {
  console.log(`Log file rotated: ${rotatedFile}`);
  // Additional actions, such as compression, can be performed here.
});

Notes

• Ensure that the directory specified in dir exists and is writable by the application.
• The enabled option can be used to turn off logging without removing the transport configuration.
• The compress option, when enabled, compresses rotated files into .gz format and deletes the original file after successful compression.
• The immutable option ensures that rotated files are not modified after creation.
• The rotated event provides a hook for custom post-rotation actions, such as archiving or uploading rotated files.

License

This project is licensed under the MIT License. See the LICENSE file for details.