slog: Fiber middleware

Fiber middleware to log http requests using slog.

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
• slog-parquet: A slog handler for Parquet + Object Storage

🚀 Install

go get github.com/samber/slog-fiber

Compatibility: go >= 1.21

No breaking changes will be made to exported APIs before v2.0.0.

💡 Usage

Minimal

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

app := fiber.New()

app.Use(slogfiber.New(logger))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// time=2023-04-10T14:00:00.000+00:00 level=INFO msg="Incoming request" status=200 method=GET path=/ ip=::1 latency=25.958µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00.000+00:00 request-id=229c7fc8-64f5-4467-bc4a-940700503b0d

Using custom time formatters

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	slogformatter "github.com/samber/slog-formatter"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
//   - RFC3339 with UTC time format.
logger := slog.New(
	slogformatter.NewFormatterHandler(
		slogformatter.TimezoneConverter(time.UTC),
		slogformatter.TimeFormatter(time.RFC3339, nil),
	)(
		slog.NewTextHandler(os.Stdout, nil),
	),
)

app := fiber.New()

app.Use(slogfiber.New(logger))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// time=2023-04-10T14:00:00.000+00:00 level=INFO msg="Incoming request" status=200 method=GET path=/ ip=::1 latency=25.958µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00Z request-id=229c7fc8-64f5-4467-bc4a-940700503b0d

Using custom logger sub-group

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

app := fiber.New()

app.Use(slogfiber.New(logger.WithGroup("http")))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// time=2023-04-10T14:00:00.000+00:00 level=INFO msg="Incoming request" http.status=200 http.method=GET http.path=/ http.ip=::1 http.latency=25.958µs http.user-agent=curl/7.77.0 http.time=2023-04-10T14:00:00Z http.request-id=229c7fc8-64f5-4467-bc4a-940700503b0d

Add logger to a single route

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

app := fiber.New()

app.Use(slogfiber.New(logger))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// time=2023-04-10T14:00:00.000+00:00 level=INFO msg="Incoming request" status=200 method=GET path=/ ip=::1 latency=25.958µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00Z request-id=229c7fc8-64f5-4467-bc4a-940700503b0d

Adding custom attributes

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

// Add an attribute to all log entries made through this logger.
logger = logger.With("env", "production")

app := fiber.New()

app.Use(slogfiber.New(logger.WithGroup("http")))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// time=2023-04-10T14:00:00.000+00:00 level=INFO msg="Incoming request" env=production status=200 method=GET path=/ ip=::1 latency=25.958µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00Z request-id=229c7fc8-64f5-4467-bc4a-940700503b0d

JSON output

import (
	"github.com/gofiber/fiber/v2"
	slogfiber "github.com/samber/slog-fiber"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil)),

app := fiber.New()

app.Use(slogfiber.New(logger))

app.Get("/", func(c *fiber.Ctx) error {
	return c.SendString("Hello, World 👋!")
})

app.Listen(":4242")

// output:
// {"time":"2023-04-10T14:00:00Z","level":"INFO","msg":"Incoming request","status":200,"method":"GET","path":"/","ip":"::1","latency":26750,"user-agent":"curl/7.77.0","time":"2023-04-10T14:00:00Z","request-id":"04201917-d7ba-4b20-a3bb-2fffba5f2bd9"}

🤝 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.