Handler for golang.org/x/exp/slog
that annotates logs with slog.Attr set on the context. Provides methods for
adding slog.Attr to the context and a slog.Handler for automatically reading
them from the context and adding them to log lines. Useful for adding fields
such as request_id, xray_trace_id, or caller to log lines.
Use ctxlog.WithAttrs(ctx, attrs...) to add slog.Attr to the context. Use
ctxlog.NewHandler(baseHandler) to create a new slog.Handler that reads attrs
from the context and adds them to log lines automatically.
package main
import (
"context"
"golang.org/x/exp/slog"
"github.com/cyrusaf/ctxlog"
)
func main() {
ctx := context.Background()
// Create ctxlog and json logger and set it as the default logger
logger := slog.New(ctxlog.NewHandler(slog.NewJSONHandler(os.Stdout)))
slog.SetDefault(logger)
// Can set attrs on the context using ctxlog.WithAttrs(ctx, ...slog.Attr)
ctx = ctxlog.WithAttrs(ctx, slog.String("hello", "world"))
// Use slog methods such as InfoCtx and the ctxlog handler will automatically
// attach attrs from the context to the structured logs.
slog.InfoCtx(ctx, "test")
// Output:{"level":"INFO","msg":"test","hello":"world"}
}