slog: Sentry handler

A Sentry Handler for slog Go library.

---

^{Sponsored by:}

Cut Kubernetes & AI costs, boost application stability

100% OpenTelemetry-native observability platform
Simple to use, built on open standards, and designed for full cost control

---

See also:

• slog-multi: slog.Handler chaining, fanout, routing, failover, load balancing...
• slog-formatter: slog attribute formatting
• slog-sampling: slog sampling policy
• slog-mock: slog.Handler for test purposes

HTTP middlewares:

• slog-gin: Gin middleware for slog logger
• slog-echo: Echo middleware for slog logger
• slog-fiber: Fiber middleware for slog logger
• slog-chi: Chi middleware for slog logger
• slog-http: net/http middleware for slog logger

Loggers:

• slog-zap: A slog handler for Zap
• slog-zerolog: A slog handler for Zerolog
• slog-logrus: A slog handler for Logrus

Log sinks:

• slog-datadog: A slog handler for Datadog
• slog-betterstack: A slog handler for Betterstack
• slog-rollbar: A slog handler for Rollbar
• slog-loki: A slog handler for Loki
• slog-sentry: A slog handler for Sentry
• slog-syslog: A slog handler for Syslog
• slog-logstash: A slog handler for Logstash
• slog-fluentd: A slog handler for Fluentd
• slog-graylog: A slog handler for Graylog
• slog-quickwit: A slog handler for Quickwit
• slog-slack: A slog handler for Slack
• slog-telegram: A slog handler for Telegram
• slog-mattermost: A slog handler for Mattermost
• slog-microsoft-teams: A slog handler for Microsoft Teams
• slog-webhook: A slog handler for Webhook
• slog-kafka: A slog handler for Kafka
• slog-nats: A slog handler for NATS
• slog-parquet: A slog handler for Parquet + Object Storage
• slog-channel: A slog handler for Go channels

🚀 Install

go get github.com/samber/slog-sentry/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-sentry/v2

Handler options

type Option struct {
    // Level sets the minimum log level to capture and send to Sentry.
    // Logs at this level and above will be processed. The default level is debug.
    Level slog.Leveler
    // Hub specifies the Sentry Hub to use for capturing events.
    // If not provided, the current Hub is used by default.
    Hub *sentry.Hub

    // Converter is an optional function that customizes how log records
    // are converted into Sentry events. By default, the DefaultConverter is used.
    Converter Converter
    // AttrFromContext is an optional slice of functions that extract attributes
    // from the context. These functions can add additional metadata to the log entry.
    AttrFromContext []func(ctx context.Context) []slog.Attr

    // AddSource is an optional flag that, when set to true, includes the source
    // information (such as file and line number) in the Sentry event.
    // This can be useful for debugging purposes.
    AddSource bool
    // ReplaceAttr is an optional function that allows for the modification or
    // replacement of attributes in the log record. This can be used to filter
    // or transform attributes before they are sent to Sentry.
    ReplaceAttr func(groups []string, a slog.Attr) slog.Attr

    // BeforeSend is an optional function that allows for the modification of
    // the Sentry event before it is sent to the server. This can be used to add
    // additional context or modify the event payload.
    BeforeSend func(event *sentry.Event) *sentry.Event
}

Other global parameters:

slogsentry.SourceKey = "source"
slogsentry.ContextKey = "extra"
slogsentry.ErrorKeys = []string{"error", "err"}
slogsentry.LogLevels = map[slog.Level]sentry.Level{...}

Supported attributes

The following attributes are interpreted by slogsentry.DefaultConverter:

Other attributes will be injected in context Sentry field.

Users and tags must be of type slog.Group. Eg:

slog.Group("user",
    slog.String("id", "user-123"),
    slog.String("username", "samber"),
    slog.Time("created_at", time.Now()),
)

The Sentry agent is responsible for collecting modules.

Example

import (
    "github.com/getsentry/sentry-go"
    slogsentry "github.com/samber/slog-sentry/v2"
    "log/slog"
)

func main() {
    err := sentry.Init(sentry.ClientOptions{
        Dsn:           myDSN,
        EnableTracing: false,
    })
    if err != nil {
        log.Fatal(err)
    }

    defer sentry.Flush(2 * time.Second)

    logger := slog.New(slogsentry.Option{Level: slog.LevelDebug}.NewSentryHandler())
    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 request
    logger.
        With(
            slog.Group("user",
                slog.String("id", "user-123"),
                slog.Time("created_at", time.Now()),
            ),
        ).
        With("request", httpRequest)
        With("status", 200).
        Info("received http request")
}

Tracing

Import the samber/slog-otel library.

import (
	slogsentry "github.com/samber/slog-sentry"
	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(
		slogsentry.Option{
			// ...
			AttrFromContext: []func(ctx context.Context) []slog.Attr{
				slogotel.ExtractOtelAttrFromContext([]string{"tracing"}, "trace_id", "span_id"),
			},
		}.NewSentryHandler(),
	)

	logger.ErrorContext(ctx, "a message")
}

🤝 Contributing

• Ping me on twitter @samuelberthe (DMs, mentions, whatever :))
• Fork the project
• Fix open issues or request new features

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.