GNU social comes with a minimalist logger class. In conformance with the twelve-factor app methodology, it sends messages starting from the WARNING level to stderr.

The minimal log level can be changed by setting the SHELL_VERBOSITY environment variable:

SHELL_VERBOSITY valueMinimum log level

Log Levels

GNU social supports the logging levels described by RFC 5424.

  • DEBUG (100): Detailed debug information.

  • INFO (200): Interesting events. Examples: User logs in, SQL logs.

  • NOTICE (250): Normal but significant events.

  • WARNING (300): Exceptional occurrences that are not errors. Examples: Use of deprecated APIs, poor use of an API, undesirable things that are not necessarily wrong.

  • ERROR (400): Runtime errors that do not require immediate action but should typically be logged and monitored.

  • CRITICAL (500): Critical conditions. Example: Application component unavailable, unexpected exception.

  • ALERT (550): Action must be taken immediately. Example: Entire website down, database unavailable, etc. This should trigger the SMS alerts and wake you up.

  • EMERGENCY (600): Emergency: system is unusable.


Log::level(message: string, context: array);

  • The message MUST be a string or object implementing __toString().

  • The message MAY contain placeholders in the form: {foo} where foo will be replaced by the context data in key "foo".

  • The context array can contain arbitrary data. The only assumption that can be made by implementors is that if an Exception instance is given to produce a stack trace, it MUST be in a key named "exception".

Where Logs are Stored

By default, log entries are written to the var/log/dev.log file when you’re in the dev environment. In the prod environment, logs are written to var/log/prod.log, but only during a request where an error or high-priority log entry was made (i.e. Log::error() , Log::critical(), Log::alert() or Log::emergency()).

Example usage

Log::info('hello, world.');
// Using the logging context, allowing to pass an array of data along the record:
Log::info('Adding a new user', ['username' => 'Seldaek']);