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module Netplex_log

: sig

Loggers

A logger is usually configured in the config file. The logging section is inside controller, e.g.

netplex {
         ...
         controller {
           ...
           logging { ... };
           ...
         }
         ...
       }

The possible types of logging sections are explained below. If there are several logging sections, the messages are sent to all configured loggers.

Instead of configuring loggers in the config file, one can also create loggers from config objects like generic_config.

See also [root:Netplex_intro].logging for more documentation.

#
class type generic_config =
#
method log_format : string
#
method log_component : string
#
method log_subchannel : string
#
method log_max_level : Netplex_types.level
#
val channel_logger : Pervasives.out_channel -> Netplex_types.logger

Outputs messages to the channel

#
val channel_logger_from_obj : generic_config -> Pervasives.out_channel -> Netplex_types.logger

Outputs messages to the channel

#
val stderr_logger_factory : Netplex_types.logger_factory

Reads a logging section like

logging {
            type = "stderr";
            format = "<format string>";
            component = "<name_of_component>";
            subchannel = "<name_of_subchannel>";
            max_level = "<max_level>";
         }
  • format: Optional format string. See below.
  • component: Optional component selector. See below.
  • subchannel: Optional subchannel selector. See below.
  • max_level: Optional maximum log level. See below.
#
val file_logger : string -> Netplex_types.logger

Writes messages to this file

#
val file_logger_from_obj : generic_config -> string -> Netplex_types.logger

Writes messages to this file

#
val file_logger_factory : Netplex_types.logger_factory

Reads a logging section like

logging {
            type = "file";
            file = "/path/to/logfile";
            format = "<format string>";
            component = "<name_of_component>";
            subchannel = "<name_of_subchannel>";
            max_level = "<max_level>";
         }
  • file: Log messages are appended to this file.
  • format: Optional format string. See below.
  • component: Optional component selector. See below.
  • subchannel: Optional subchannel selector. See below.
  • max_level: Optional maximum log level. See below.
#
class type multi_file_config =
inherit generic_config
#
method log_directory : string
#
method log_files : (string * string * [
| Netplex_types.level
| `All
] * string * string) list

Triples (component, subchannel, max_level, file, format). Use * as wildcard in component and subchannel.

Currently, `All is a synonym for the `Debug level.

#
val multi_file_logger : multi_file_config -> Netplex_types.logger
#
val multi_file_logger_factory : Netplex_types.logger_factory

Reads a logging section like

logging {
            type = "multi_file";
            directory = "/path/to/logdir";
            format = "<format string>";
            file {
                component = "<name_of_component>";
                subchannel = "<name_of_subchannel>";
                max_level = "<max_level>";
                file = "<logfile>";
                format = "<format string>";
            };
            file { ... }; ...
         }
  • format: Optional format string. See below.
  • component: Optional component selector. See below.
  • subchannel: Optional subchannel selector. See below.
  • max_level: Optional maximum log level. See below.
#
class type syslog_config =
inherit generic_config
#
method log_identifier : string
#
method log_facility : Netsys_posix.syslog_facility
#
val syslog_logger : syslog_config -> Netplex_types.logger

Creates a logger writing to syslog

#
val syslog_logger_factory : Netplex_types.logger_factory

Reads a logging section like

logging {
            type = "syslog";
            format = "<format string>";
            identifier = "<identifier>";
            facility = "<facility name>";
            component = "<name_of_component>";
            subchannel = "<name_of_subchannel>";
            max_level = "<max_level>";
         }

All parameters except type are optional:

  • facility: The faciltiy like LOCAL0, USER, ...
  • identifier: An identifier prefixing every message
  • format: Optional format string. See below.
  • component: Optional component selector. See below.
  • subchannel: Optional subchannel selector. See below.
  • max_level: Optional maximum log level. See below.
#
val logger_factories : Netplex_types.logger_factory list

All built-in logger factories

#
val level_weight : Netplex_types.level -> int

An integer corresponding to the level

#
val level_of_string : string -> Netplex_types.level

Convert a string to a level

Common parameters

Logging parameters that can occur in all logging configurations:

format

The format string may include variable parts in the syntax $name or ${name}. The following variable specifications are defined:

  • timestamp: the time in standard format (as set in Netlog.current_formatter)
  • timestamp:<format> the time in custom format where <format> is a [root:Netdate] format string
  • timestamp:unix: the time in seconds since the epoch
  • component: the name of the component emitting the log message
  • subchannel: the name of the subchannel
  • level: the log level
  • message: the log message

component

The component name restricts logging to the given Netplex component. One can use the wildcard "*".

subchannel

The subchannel name restricts logging to this subchannel. One can use the wildcard "*".

max_level

The max_level specifier restricts logging to messages with at most this level. Levels are "emerg", "alert", "crit", "err", "warning", "notice", "info", "debug" (in order of increasing level).

end