Logger

• see winston docs for details on usage
• colorizes console logging
• uses winston-daily-rotate-file for rotating error and combined log files

usage

$ npm i @vampiire/node-logger

const createLogger = require("@vampiire/node-logger");

const logger = createLogger(); // defaults

const logger = createLogger({ ... }); // custom options

// shorthand
const logger = require('@vampiire/node-logger')(); // default
const logger = require('@vampiire/node-logger')({ ... }); // custom options

usage for errors

• pass the error directly to the logger.error

stuff.then().catch(logger.error);

try {
  stuff();
} catch (error) {
  logger.error(error);
}

logging format

<log level> [<HH:mm:ss timestamp>] - <message>

error format

<log level> [<HH:mm:ss timestamp>] - <error.message>
<
  error stack trace
  on new line
>

expected env vars

NODE_ENV=
ERROR_LOGS_DIR=
COMBINED_LOGS_DIR=

• NODE_ENV
  • !== production: enables console transport, disables file transports
  • === production: disables console transport, enables file transports
  • override this behavior with options``.enableConsole/.enableFiles
• the directory paths can be:
  • relative (to the project): ERROR_LOGS_DIR=logs/errors
  • absolute (must exist / have permission to write): ERROR_LOGS_DIR=/Users/username/logs/errors
• ERROR_LOGS_DIR: where the error log files will be written.
• COMBINED_LOGS_DIR: where the combined log files will be written.
  • combined logs are written for all logs at or below the logger.level configuration
• log files have the name %DATE%.log where the date is the current YYYY-MM-DD format
  • they are rotated daily (new file each day)
  • the maxFiles option is set to 14 days by default (will keep logs up to 14 days before removing)

configuration options & defaults

const {
  enableFiles = process.env.NODE_ENV === "production",
  enableConsole = process.env.NODE_ENV !== "production",
  errorMaxFiles = "14d",
  combinedMaxFiles = "14d",
  levels = {
    error: 0,
    warn: 1,
    info: 2,
    debug: 3,
  },
  colors = {
    error: "bold red",
    warn: "italic yellow",
    info: "bold white",
    debug: "cyan",
  },
} = options;

• enableFiles: adds the rotating file transports for errors and combined
  • errorMaxFiles: number of days / size to keep error files before removing
  • combinedMaxFiles: number of days / size to keep combined files before removing
  • see winston-daily-rotate-file for details
• enabledConsole: adds the console transport (colorized)
• levels: winston logger levels see winston levels
• colors: console colorizing options see winston colors