GitHub - samber/slog-fluentd: 🚨 slog: Fluentd handler (original) (raw)

slog: Fluentd handler

A Fluentd Handler for slog Go library.

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-fluentd/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-fluentd/v2

Fluentd settings

<source>
    @type forward
    bind 0.0.0.0
    port 24224
</source>

Handler options

type Option struct { // log level (default: debug) Level slog.Leveler

// connection to Fluentd
Client *fluentd.Fluentd
Tag    string

// 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

}

Attributes will be injected in log payload.

Fluentd tag can be inserted in logger options or in a record attribute of type string.

Other global parameters:

slogfluentd.SourceKey = "source" slogfluentd.ContextKey = "extra" slogfluentd.ErrorKeys = []string{"error", "err"}

Example

import ( "github.com/fluent/fluent-logger-golang/fluent" slogfluentd "github.com/samber/slog-fluentd/v2" "log/slog" )

func main() { // docker-compose up -d client, err := fluent.New(fluent.Config{ FluentHost: "localhost", FluentPort: 24224, FluentNetwork: "tcp", MarshalAsJSON: true, Async: true, }) if err != nil { log.Fatal(err.Error()) }

logger := slog.New(
    slogfluentd.Option{
        Level: slog.LevelDebug,
        Client: client,
        Tag: "api",
    }.NewFluentdHandler(),
)
logger = logger.
    With("environment", "dev").
    With("release", "v1.0.0")

// log error
logger.
    With("tag", "api.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")

}

Output:

// tag: api.sql { "timestamp":"2023-04-10T14:00:0.000000+00:00", "level":"ERROR", "message":"caramba!", "tag":"api.sql", "error":{ "error":"could not count users", "kind":"errors.errorString", "stack":null }, "extra":{ "environment":"dev", "release":"v1.0.0", "query.statement":"SELECT COUNT() FROM users;", "query.duration": "1s" } }

// tag: api { "timestamp":"2023-04-10T14:00:0.000000+00:00", "level":"INFO", "message":"user registration", "tag":"api", "error":null, "extra":{ "environment":"dev", "release":"v1.0.0", "user":{ "id":"user-123", "created_at":"2023-04-10T14:00:0.000000+00:00" } } }

Tracing

Import the samber/slog-otel library.

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

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.