slogfluentd

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-gin: Gin middleware for slog logger
• slog-echo: Echo middleware for slog logger
• slog-fiber: Fiber middleware for slog logger
• slog-datadog: A slog handler for Datadog
• slog-rollbar: A slog handler for Rollbar
• 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-loki: A slog handler for Loki
• 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

🚀 Install

go get github.com/samber/slog-fluentd

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-fluentd

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
}

Attributes will be injected in log payload.

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

Example

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

func main() {
	// docker-compose up -d
	client, err := fluent.New(fluent.Config{
		FluentHost:    "localhost",
		FluentPort:    24224,
		FluentNetwork: "tcp",
		MarshalAsJSON: 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"
        }
    }
}

🤝 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.