ctxslog

README

ctxslog

handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{ReplaceAttr: replace})
slog.SetDefault(slog.New(ctxslog.New(handler)))

ctx := context.Background()
// associate the key my_context and the value foo-bar with the context.
ctx = ctxslog.With(ctx, "my_context", "foo-bar")

slog.InfoContext(ctx, "hello", "count", 42)
slog.InfoContext(ctx, "world")
// Output:
// time=2023-08-03T18:10:20.424+09:00 level=INFO msg=hello count=42 my_context=foo-bar
// time=2023-08-03T18:10:20.424+09:00 level=INFO msg=world my_context=foo-bar

Documentation

Overview

Example

package main

import (
	"context"
	"log/slog"
	"os"

	"github.com/shogo82148/ctxslog"
)

func main() {
	// it's for testing.
	replace := func(groups []string, a slog.Attr) slog.Attr {
		// Remove time.
		if a.Key == slog.TimeKey && len(groups) == 0 {
			return slog.Attr{}
		}
		return a
	}

	handler := slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{ReplaceAttr: replace})
	slog.SetDefault(slog.New(ctxslog.New(handler)))

	ctx := context.Background()
	ctx = ctxslog.With(ctx, "my_context", "foo-bar")

	slog.InfoContext(ctx, "hello", "count", 42)
	slog.InfoContext(ctx, "world")

}

Output:
level=INFO msg=hello count=42 my_context=foo-bar
level=INFO msg=world my_context=foo-bar

Index

• func New(parent slog.Handler) slog.Handler
• func With(ctx context.Context, args ...any) context.Context
• func WithAttrs(ctx context.Context, attrs ...slog.Attr) context.Context
• func WithLevel(ctx context.Context, level slog.Level) context.Context

Examples

• Package

Functions

func New

func New(parent slog.Handler) slog.Handler

New returns a new slog.Handler that injects the attributes from the context.

func With

func With(ctx context.Context, args ...any) context.Context

With returns a new context with the given attributes. The attributes are added into the log record.

func WithAttrs

func WithAttrs(ctx context.Context, attrs ...slog.Attr) context.Context

WithAttrs is a more efficient version of With that accepts only log/slog.Attrs.

func WithLevel

func WithLevel(ctx context.Context, level slog.Level) context.Context

WithLevel configures the minimum record level that will be logged in the context.