Internal logger

Klogging has an internal logger that emits string messages to the console.

Usage

The core function log(String, Level, String, Exception?) is called by utility functions for five levels:

• trace("Sink", "Forwarding event ${event.id} to sink $name")

• debug("Emitter", "Starting events channel")

• info("Configuration", "Setting configuration using the DSL with append=$append")

• warn("JsonConfiguration", "Exception parsing JSON", ex)

• error("Sink", "A serious error has occurred", ex)

note

Message templates are not currently supported by the internal logger.

Minimum logging level

The internal logger has a minimum level from which it will emit log messages, set by the ‘global’ variable kloggingMinLogLevel.

• The level is INFO by default.

• It can be changed by the environment variable KLOGGING_MIN_LOG_LEVEL

Under the hood

The code constructs log events, renders them as string messages using a specific renderer and sends them to the console.

• If the logging level is INFO or lower, they are sent to the standard output stream.
• If the logging level is WARN or higher, they are sent to the standard error stream. Some shells will show these messages in a different colour (e.g. red).