slog: Channel handler
A Go channel Handler for slog Go library.
See also:
HTTP middlewares:
Loggers:
Log sinks:
🚀 Install
go get github.com/samber/slog-channel
Compatibility: go >= 1.21
No breaking changes will be made to exported APIs before v2.0.0.
💡 Usage
GoDoc: https://pkg.go.dev/github.com/samber/slog-channel
Handler options
type Option struct {
// log level (default: debug)
Level slog.Leveler
// Channel
Channel chan *slog.Record
Blocking bool // blocks on when channel is full
// optional: customize record builder
Converter Converter
// optional: fetch attributes from context
AttrFromContext []func(ctx context.Context) []slog.Attr
// optional: see slog.HandlerOptions
AddSource bool
ReplaceAttr func(groups []string, a slog.Attr) slog.Attr
}
Other global parameters:
slogchannel.SourceKey = "source"
Example
import (
"fmt"
"net/http"
"time"
slogchannel "github.com/samber/slog-channel/v2"
"log/slog"
)
func main() {
// warning: a too small buffer and too slow consumer might be blocking
ch := make(chan *slog.Record, 100)
defer close(ch)
logger := slog.New(slogchannel.Option{Level: slog.LevelDebug, Channel: ch}.NewChannelHandler())
logger = logger.With("release", "v1.0.0")
logger.
With(
slog.Group("user",
slog.String("id", "user-123"),
slog.Time("created_at", time.Now()),
),
).
With("error", fmt.Errorf("an error")).
Error("a message", slog.Int("count", 1))
record := <-ch
fmt.Println(record)
}
Tracing
Import the samber/slog-otel library.
import (
slogchannel "github.com/samber/slog-channel"
slogotel "github.com/samber/slog-otel"
"go.opentelemetry.io/otel/sdk/trace"
)
func main() {
tp := trace.NewTracerProvider(
trace.WithSampler(trace.AlwaysSample()),
)
tracer := tp.Tracer("hello/world")
ctx, span := tracer.Start(context.Background(), "foo")
defer span.End()
span.AddEvent("bar")
logger := slog.New(
slogchannel.Option{
// ...
AttrFromContext: []func(ctx context.Context) []slog.Attr{
slogotel.ExtractOtelAttrFromContext([]string{"tracing"}, "trace_id", "span_id"),
},
}.NewChannelHandler(),
)
logger.ErrorContext(ctx, "a message")
}
🤝 Contributing
Don't hesitate ;)
# Install some dev dependencies
make tools
# Run tests
make test
# or
make watch-test
👤 Contributors
💫 Show your support
Give a ⭐️ if this project helped you!
📝 License
Copyright © 2023 Samuel Berthe.
This project is MIT licensed.