syslogger

A syslog backend for erlang logger.

Usage

The easiest way to use syslogger is to just include it as a dependency in your rebar.config like this:

{deps,
 [
  { 'syslogger', "*", {git, "git://github.com/garazdawi/syslogger", {branch, "master"}}}
 ]
}.

The default configuration is then used and any log messages will turn up in the local syslog.

Build Requirements

You need to have Erlang/OTP, a C compiler, rebar3 and the autoconf toolchain installed.

apt-get install build-essential autoconf libtool

Recommended Configuration

If you just want to get started with syslogger, the recommended configuration in the system's sys.config is:

{kernel, logger, [{handler, default, undefined}]}.
{syslogger,
  {log_opts, [cons, pid, perror]},
  {logger, [{handler, default, syslogger,
               #{ formatter => {logger_formatter, #{single_line => true}}}}]}
}.

Configuration

The syslogger application can be used either by configuring the handlers through application variables, or by using the logger:add_handler/2 API.

For instance if you want to add two handlers that log to two different syslog facilities just add this to your sys.config.

{syslogger,
  {ident, "myapp"},
  {log_opts, [cons, pid, perror]},
  {logger, [{handler, user_syslogger, syslogger, #{ facility => user }},
            {handler, local0_syslogger, syslogger, #{ facility => local0 }}]
   }
}.

This will add two syslogger instances to the Erlang logger that use different facilities.

The same effect could have been achieved by using the logger API like this:

logger:add_handler(user_syslogger, syslogger, #{ facility => user }),
logger:add_handler(local0_syslogger, syslogger, #{ facility => local0 }).

Each syslogger handler can be configured using a map with these configuration options:

• facility: The syslog facility to log though.
  • Default: undefined i.e. the default set by openlog or the system default.

The openlog call can get the following init at startup:

• ident: The syslog identifier that is prepended to each log message.
  • Default: The value of init:get_argument(progname).
• facility: The syslog facility to log though.
  • Default: user
• log_opts: The syslog options (as a list) to use.
  • Default: []

For more details of what each of these options do see syslog(3).