# slog: Zerolog handler [![tag](https://img.shields.io/github/tag/samber/slog-zerolog.svg)](https://github.com/samber/slog-zerolog/releases) ![Go Version](https://img.shields.io/badge/Go-%3E%3D%201.21-%23007d9c) [![GoDoc](https://godoc.org/github.com/samber/slog-zerolog?status.svg)](https://pkg.go.dev/github.com/samber/slog-zerolog) ![Build Status](https://github.com/samber/slog-zerolog/actions/workflows/test.yml/badge.svg) [![Go report](https://goreportcard.com/badge/github.com/samber/slog-zerolog)](https://goreportcard.com/report/github.com/samber/slog-zerolog) [![Coverage](https://img.shields.io/codecov/c/github/samber/slog-zerolog)](https://codecov.io/gh/samber/slog-zerolog) [![Contributors](https://img.shields.io/github/contributors/samber/slog-zerolog)](https://github.com/samber/slog-zerolog/graphs/contributors) [![License](https://img.shields.io/github/license/samber/slog-zerolog)](./LICENSE) A [Zerolog](https://github.com/rs/zerolog) Handler for [slog](https://pkg.go.dev/log/slog) Go library.
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**See also:** - [slog-multi](https://github.com/samber/slog-multi): `slog.Handler` chaining, fanout, routing, failover, load balancing... - [slog-formatter](https://github.com/samber/slog-formatter): `slog` attribute formatting - [slog-sampling](https://github.com/samber/slog-sampling): `slog` sampling policy - [slog-mock](https://github.com/samber/slog-mock): `slog.Handler` for test purposes **HTTP middlewares:** - [slog-gin](https://github.com/samber/slog-gin): Gin middleware for `slog` logger - [slog-echo](https://github.com/samber/slog-echo): Echo middleware for `slog` logger - [slog-fiber](https://github.com/samber/slog-fiber): Fiber middleware for `slog` logger - [slog-chi](https://github.com/samber/slog-chi): Chi middleware for `slog` logger - [slog-http](https://github.com/samber/slog-http): `net/http` middleware for `slog` logger **Loggers:** - [slog-zap](https://github.com/samber/slog-zap): A `slog` handler for `Zap` - [slog-zerolog](https://github.com/samber/slog-zerolog): A `slog` handler for `Zerolog` - [slog-logrus](https://github.com/samber/slog-logrus): A `slog` handler for `Logrus` **Log sinks:** - [slog-datadog](https://github.com/samber/slog-datadog): A `slog` handler for `Datadog` - [slog-betterstack](https://github.com/samber/slog-betterstack): A `slog` handler for `Betterstack` - [slog-rollbar](https://github.com/samber/slog-rollbar): A `slog` handler for `Rollbar` - [slog-loki](https://github.com/samber/slog-loki): A `slog` handler for `Loki` - [slog-sentry](https://github.com/samber/slog-sentry): A `slog` handler for `Sentry` - [slog-syslog](https://github.com/samber/slog-syslog): A `slog` handler for `Syslog` - [slog-logstash](https://github.com/samber/slog-logstash): A `slog` handler for `Logstash` - [slog-fluentd](https://github.com/samber/slog-fluentd): A `slog` handler for `Fluentd` - [slog-graylog](https://github.com/samber/slog-graylog): A `slog` handler for `Graylog` - [slog-quickwit](https://github.com/samber/slog-quickwit): A `slog` handler for `Quickwit` - [slog-slack](https://github.com/samber/slog-slack): A `slog` handler for `Slack` - [slog-telegram](https://github.com/samber/slog-telegram): A `slog` handler for `Telegram` - [slog-mattermost](https://github.com/samber/slog-mattermost): A `slog` handler for `Mattermost` - [slog-microsoft-teams](https://github.com/samber/slog-microsoft-teams): A `slog` handler for `Microsoft Teams` - [slog-webhook](https://github.com/samber/slog-webhook): A `slog` handler for `Webhook` - [slog-kafka](https://github.com/samber/slog-kafka): A `slog` handler for `Kafka` - [slog-nats](https://github.com/samber/slog-nats): A `slog` handler for `NATS` - [slog-parquet](https://github.com/samber/slog-parquet): A `slog` handler for `Parquet` + `Object Storage` - [slog-channel](https://github.com/samber/slog-channel): A `slog` handler for Go channels ## 🚀 Install ```sh go get github.com/samber/slog-zerolog/v2 ``` **Compatibility**: go >= 1.21 No breaking changes will be made to exported APIs before v3.0.0. ## 💡 Usage GoDoc: [https://pkg.go.dev/github.com/samber/slog-zerolog/v2](https://pkg.go.dev/github.com/samber/slog-zerolog/v2) ### Handler options ```go type Option struct { // log level (default: debug) // you can use ZeroLogLeveler to retrieve the level from the global zerolog instance or a custom one Level slog.Leveler // optional: zerolog logger (default: zerolog.Logger) Logger *zerolog.Logger // optional: don't add timestamp to record NoTimestamp bool // optional: customize json payload 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: ```go slogzerolog.SourceKey = "source" slogzerolog.ErrorKeys = []string{"error", "err"} slogzerolog.LogLevels = map[slog.Level]zerolog.Level{...} ``` ### Example ```go import ( "github.com/rs/zerolog" slogzerolog "github.com/samber/slog-zerolog/v2" "os" "log/slog" ) func main() { zerologLogger := zerolog.New(zerolog.ConsoleWriter{Out: os.Stderr}) logger := slog.New(slogzerolog.Option{Level: slog.LevelDebug, Logger: &zerologLogger}.NewZerologHandler()) logger = logger. With("environment", "dev"). With("release", "v1.0.0") // log error logger. With("category", "sql"). With("query.statement", "SELECT COUNT(*) FROM users;"). With("query.duration", 1*time.Second). With("error", fmt.Errorf("could not count users")). Error("caramba!") // log user signup logger. With( slog.Group("user", slog.String("id", "user-123"), slog.Time("created_at", time.Now()), ), ). Info("user registration") } ``` ### Tracing Import the samber/slog-otel library. ```go import ( slogzerolog "github.com/samber/slog-zerolog" 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( slogzerolog.Option{ // ... AttrFromContext: []func(ctx context.Context) []slog.Attr{ slogotel.ExtractOtelAttrFromContext([]string{"tracing"}, "trace_id", "span_id"), }, }.NewZerologHandler(), ) logger.ErrorContext(ctx, "a message") } ``` ### Zerolog level mapping Use the `slogzerolog.ZeroLogLeveler` as `slogzerolog.Option.Level` (`slog.Leveler`) to set the `slog.Level` from `zerolog.Level`. Currently following levels are mapped: | zerolog | slog | |----------|-----------| | Trace-N | Debug-1-N | | Trace | Debug-1 | | Debug | Debug | | Info | Info | | Warn | Warn | | Error | Error | | Panic | Error | | Fatal | Error | | NoLevel | Info | | Disabled | Debug-1 | | * | Info | ```go import ( "github.com/rs/zerolog" slogzerolog "github.com/samber/slog-zerolog/v2" "os" "log/slog" ) func main() { zerologLogger := zerolog.New(zerolog.ConsoleWriter{Out: os.Stderr}) logger := slog.New(slogzerolog.Option{Level: ZeroLogLeveler{&zerologLogger}, Logger: &zerologLogger}.NewZerologHandler()) logger.Trace("caramba!") } ``` ## 🤝 Contributing - Ping me on twitter [@samuelberthe](https://twitter.com/samuelberthe) (DMs, mentions, whatever :)) - Fork the [project](https://github.com/samber/slog-zerolog) - Fix [open issues](https://github.com/samber/slog-zerolog/issues) or request new features Don't hesitate ;) ```bash # Install some dev dependencies make tools # Run tests make test # or make watch-test ``` ## 👤 Contributors ![Contributors](https://contrib.rocks/image?repo=samber/slog-zerolog) ## 💫 Show your support Give a ⭐️ if this project helped you! [![GitHub Sponsors](https://img.shields.io/github/sponsors/samber?style=for-the-badge)](https://github.com/sponsors/samber) ## 📝 License Copyright © 2023 [Samuel Berthe](https://github.com/samber). This project is [MIT](./LICENSE) licensed.