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SMTP Appender for log4js CodeQL Node.js CI

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Sends log events as emails. If you use this appender, you should also call log4js.shutdown when your application closes so that any remaining emails can be sent. Many of the configuration options below are passed through to nodemailer, so you should read their docs to get the most out of this appender.

npm install log4js
npm install @log4js-node/smtp

Configuration

Example (default config)

log4js.configure({
  appenders: {
    'email': {
      type: '@log4js-node/smtp', recipients: 'dev.team@company.name'
    }
  },
  categories: { default: { appenders: [ 'email' ], level: 'error' } }
});

This configuration will send an email using the smtp server running on localhost:25, for every log event of level ERROR and above. The email will be sent to dev.team@company.name, the subject will be the message part of the log event, the body of the email will be log event formatted by the basic layout function.

Example (logs as attachments, batched)

log4js.configure({
  appenders: {
    'email': {
      type: '@log4js-node/smtp',
      recipients: 'dev.team@company.name',
      subject: 'Latest logs',
      sender: 'my.application@company.name',
      attachment: {
        enable: true,
        filename: 'latest.log',
        message: 'See the attachment for the latest logs'
      },
      sendInterval: 3600
    }
  },
  categories: { default: { appenders: ['email'], level: 'ERROR' } }
});

This configuration will send an email once every hour, with all the log events of level 'ERROR' and above as an attached file.

Example (custom SMTP host)

log4js.configure({
  appenders: {
    email: {
      type: '@log4js-node/smtp', SMTP: { host: 'smtp.company.name', port: 8025 }, recipients: 'dev.team@company.name'
    }
  },
  categories: { default: { appenders: ['email'], level: 'info' } }
});

This configuration can also be written as:

log4js.configure({
  appenders: {
    email: {
      type: '@log4js-node/smtp',
      transport: {
        plugin: 'smtp',
        options: {
          host: 'smtp.company.name',
          port: 8025
        }
      },
      recipients: 'dev.team@company.name'
    }
  },
  categories: {
    default: { appenders: ['email'], level: 'info' }
  }
});

A similar config can be used to specify a different transport plugin than smtp. See the nodemailer docs for more details.