Logger plugin

This plugin allows you to define custom log files which may be used from HSL (logger(id, data)). The file may be reopened after a rotate using the halonctl command.

# halonctl plugin command logger reopen mylog1

Installation

Follow the instructions in our manual to add our package repository and then run the below command.

Ubuntu

apt-get install halon-extras-logger

RHEL

yum install halon-extras-logger

Configuration

For the configuration schema, see logger.schema.json.

Important!

If using the /var/log/halon/ folder as in the sample below and it does not exist, when you create it - give it the same permission as the smtpd process is using. Eg.

mkdir /var/log/halon
chown halon:staff /var/log/halon

smtpd.yaml

plugins:
  - id: logger
    config:
      logs:
        - id: mylog
          path: /var/log/halon/mylog.log
          fsync: false

Log rotation

You can use this plugin with logrotate. A sample configuration could look like this.

/var/log/halon/test.log {
    su halon halon
    create 640 halon halon
    compress
    rotate 30
    daily
    missingok
    notifempty
    postrotate
        /opt/halon/bin/halonctl plugin command logger reopen test
    endscript
}

Exported functions

These functions needs to be imported from the extras://logger module path.

logger(id, data)

Log data to a log file based on its ID.

Params

• id string - The file ID
• data string - The data

Returns

Returns true if the data was logged successfully. On error none is returned.

Example

import { logger } from "extras://logger";
logger("mylog", "hello\n");

Autoload

This plugin creates files needed and used by the smtpd process, hence this plugin does not autoload when running the hsh script interpreter. There are two issues that may occur

1. Bad file permission if logs are created by the user running hsh not the smtpd process
2. Log files may be corrupted if multiple processes are writing to the same log file simultaneously (smtpd and hsh). Do use this plugin in hsh if smtpd is running and vice versa.

To overcome the first issue, run hsh as root and use the --privdrop flag to become the same user as smtpd is using.

hsh --privdrop --plugin logger