# README
Slog
Slog (short for "structured log") is a wrapper over go-kit/log with a defined log structure and a set of helper methods.
Configurations
| Environment Variable | Default Value | Allowed Values |
|---|---|---|
| LOG_LEVEL | "info" | "debug", "info", "warn", "error" |
| LOG_CALLER_DEPTH | 4 | Z |
Log Levels & Filtering
All log levels are allowed to be logged by default. Use the config "LOG_LEVEL" to filter out.
| Set Value | |
|---|---|
| "debug" | debug + info + warn + error |
| "info" | info + warn + error |
| "warn" | warn + error |
| "error" | error |
Usage
- Log line without custom fields:
slog.Debug("the five boxing")
level=debug ts=2011-08-22T10:07:34.329181992Z caller=main.go:21 msg="the five boxing"
- Log line with custom fields:
slog.Warn("wizards jump quickly", "unit_bytes", 8008)
level=warn ts=2012-07-18T11:27:32.616223846Z caller=main.go:70 msg="the five boxing" unit_bytes=8008
- Create a logger with trace_id attached
slogger := slog.WithTraceId(ctx)
slogger.Info("the quick brown")
- Create a logger with custom fields attached
logFields := map[string]interface{}{
"integration_uuid": response.IntegrationUuid,
}
slogger := slog.WithFields(logFields)
slogger.Warn("fox jumps over")
- Create a logger with trace_id and custom fields attached
logFields := map[string]interface{}{
"integration_uuid": response.IntegrationUuid,
}
slogger := slog.WithFields(logFields).WithTraceId(ctx)
slogger.Debug("the lazy dog")
Logging Methods
slog.Debug(msg string, args ...any)
slog.Debugf(format string, args ...any)
slog.Info(msg string, args ...any)
slog.Infof(format string, args ...any)
slog.Warn(msg string, args ...any)
slog.Warnf(format string, args ...any)
slog.Error(err error, msg string, args ...any)
slog.Errorf(err error, format string, args ...any)
Helper Methods
slog.WithFields(fields map[string]any) Logger
slog.WithTraceId(ctx context.Context) Logger
slog.DefaultLogger() log.Logger
# Functions
Debug logs a line with level debug.
Debugf logs a format line with level debug.
DefaultLogger returns the default instance of logfmt logger.
Error logs a line with level error.
Errorf logs a format line with level error.
Info logs a line with level Info.
Infof logs a format line with level info.
NewLogger returns a new instance of Logger.
Warn logs a line with level warn.
Warnf logs a format line with level warn.
WithFields returns WithFields using the defaultLoggerWrapper.
WithTraceId returns WithTraceId using the defaultLoggerWrapper.
# Interfaces
Logger represents the methods supported by slog.