bedrock/lib/loggers/fileLogger.js

A core foundation for rich Web applications.

/*!
 * Copyright (c) 2012-2022 Digital Bazaar, Inc. All rights reserved.
 */
import * as brUtil from '../util.js';
import * as formatters from './formatters.js';
import {config} from '../config.js';
import path from 'path';
import {promises as fs} from 'fs';
import uidNumber from 'uid-number';
import winston from 'winston';
const cc = brUtil.config.main.computer();

// config filenames
// configured here instead of config.js due to util dependency issues
cc({
  'loggers.app.filename': () => path.join(config.paths.log, 'app.log'),
  'loggers.access.filename': () => path.join(config.paths.log, 'access.log'),
  'loggers.error.filename': () => path.join(config.paths.log, 'error.log')
});

export async function init({transports}) {
  transports.app = new winston.transports.File({
    ...config.loggers.app,
    format: formatters.fromConfig(config.loggers.app.bedrock),
  });
  transports.access = new winston.transports.File({
    ...config.loggers.access,
    format: formatters.fromConfig(config.loggers.access.bedrock),
  });
  transports.error = new winston.transports.File({
    ...config.loggers.error,
    format: formatters.fromConfig(config.loggers.error.bedrock),
  });

  // ensure all files are created and have ownership set to the
  // application process user
  const fileLoggers = Object.keys(config.loggers).filter(function(name) {
    const logger = config.loggers[name];
    return (brUtil.isObject(logger) && 'filename' in logger);
  }).map(function(name) {
    return config.loggers[name];
  });
  // TODO: run in parallel
  // see: https://github.com/digitalbazaar/bedrock/issues/88
  for(const fileLogger of fileLoggers) {
    const dirname = path.dirname(fileLogger.filename);
    // make directory and chown if requested
    await fs.mkdir(dirname, {recursive: true});
    if('bedrock' in fileLogger && fileLogger.bedrock.enableChownDir) {
      await _chown(dirname);
    }
    // check file can be opened
    const f = await fs.open(fileLogger.filename, 'a');
    await f.close();
    // always chown log file
    await _chown(fileLogger.filename);
  }

  // set unique names for file transports
  transports.app.name = 'app';
  transports.access.name = 'access';
  transports.error.name = 'error';
}

async function _chown(filename) {
  if(config.core.running.userId) {
    let uid = config.core.running.userId;
    if(typeof uid !== 'number') {
      if(process.platform === 'win32') {
        // on Windows, just get the current UID
        uid = process.getuid();
      } else {
        try {
          let gid;
          /* eslint-disable-next-line no-unused-vars */
          [uid, gid] = await new Promise((resolve, reject) => {
            uidNumber(uid, (err, uid, gid) => {
              if(err) {
                reject(err);
                return;
              }
              resolve([uid, gid]);
            });
          });
        } catch(e) {
          throw new brUtil.BedrockError(
            `Unable to convert user "${uid}" to a numeric user id. ` +
            'Try using a uid number instead.',
            'Error', {cause: e});
        }
      }
    }
    if(process.getgid) {
      await fs.chown(filename, uid, process.getgid());
    }
  }
}