viper/logger.go

105 lines
2.5 KiB
Go

package viper
import (
"context"
"fmt"
slog "github.com/sagikazarmark/slog-shim"
jww "github.com/spf13/jwalterweatherman"
)
// Logger is a unified interface for various logging use cases and practices, including:
// - leveled logging
// - structured logging
type Logger interface {
// Trace logs a Trace event.
//
// Even more fine-grained information than Debug events.
// Loggers not supporting this level should fall back to Debug.
Trace(msg string, keyvals ...interface{})
// Debug logs a Debug event.
//
// A verbose series of information events.
// They are useful when debugging the system.
Debug(msg string, keyvals ...interface{})
// Info logs an Info event.
//
// General information about what's happening inside the system.
Info(msg string, keyvals ...interface{})
// Warn logs a Warn(ing) event.
//
// Non-critical events that should be looked at.
Warn(msg string, keyvals ...interface{})
// Error logs an Error event.
//
// Critical events that require immediate attention.
// Loggers commonly provide Fatal and Panic levels above Error level,
// but exiting and panicking is out of scope for a logging library.
Error(msg string, keyvals ...interface{})
}
type jwwLogger struct{}
func (jwwLogger) Trace(msg string, keyvals ...interface{}) {
jww.TRACE.Printf(jwwLogMessage(msg, keyvals...))
}
func (jwwLogger) Debug(msg string, keyvals ...interface{}) {
jww.DEBUG.Printf(jwwLogMessage(msg, keyvals...))
}
func (jwwLogger) Info(msg string, keyvals ...interface{}) {
jww.INFO.Printf(jwwLogMessage(msg, keyvals...))
}
func (jwwLogger) Warn(msg string, keyvals ...interface{}) {
jww.WARN.Printf(jwwLogMessage(msg, keyvals...))
}
func (jwwLogger) Error(msg string, keyvals ...interface{}) {
jww.ERROR.Printf(jwwLogMessage(msg, keyvals...))
}
func jwwLogMessage(msg string, keyvals ...interface{}) string {
out := msg
if len(keyvals) > 0 && len(keyvals)%2 == 1 {
keyvals = append(keyvals, nil)
}
for i := 0; i <= len(keyvals)-2; i += 2 {
out = fmt.Sprintf("%s %v=%v", out, keyvals[i], keyvals[i+1])
}
return out
}
// WithLogger sets a custom logger.
func WithLogger(l *slog.Logger) Option {
return optionFunc(func(v *Viper) {
v.logger = l
})
}
type discardHandler struct{}
func (n *discardHandler) Enabled(_ context.Context, _ slog.Level) bool {
return false
}
func (n *discardHandler) Handle(_ context.Context, _ slog.Record) error {
return nil
}
func (n *discardHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
return n
}
func (n *discardHandler) WithGroup(name string) slog.Handler {
return n
}