slog: Gin middleware

Gin 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-gin

Compatibility: go >= 1.21

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

💡 Usage

Minimal

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

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

router := gin.New()

// Add the sloggin middleware to all routes.
// The middleware will log all requests attributes.
router.Use(sloggin.New(logger))

// Example pong request.
router.GET("/pong", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// time=2023-04-10T14:00:0.000000Z level=INFO msg="Incoming request" status=200 method=GET path=/pong ip=127.0.0.1 latency=25.5µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00.000Z

Filters

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

router := gin.New()
router.Use(
	sloggin.NewWithFilters(
		logger,
		sloggin.Accept(func (c *gin.Context) bool {
			return xxx
		}),
		sloggin.IgnoreStatus(401, 404),
	),
)

Available filters:

Accept / Ignore
AcceptMethod / IgnoreMethod
AcceptStatus / IgnoreStatus
AcceptStatusGreaterThan / IgnoreStatusLessThan
AcceptStatusGreaterThanOrEqual / IgnoreStatusLessThanOrEqual
AcceptPath / IgnorePath
AcceptPathContains / IgnorePathContains
AcceptPathPrefix / IgnorePathPrefix
AcceptPathSuffix / IgnorePathSuffix
AcceptPathMatch / IgnorePathMatch
AcceptHost / IgnoreHost
AcceptHostContains / IgnoreHostContains
AcceptHostPrefix / IgnoreHostPrefix
AcceptHostSuffix / IgnoreHostSuffix
AcceptHostMatch / IgnoreHostMatch

Using custom time formatters

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	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.DateTime, nil),
    )(
        slog.NewTextHandler(os.Stdout, nil),
    ),
)

router := gin.New()

// Add the sloggin middleware to all routes.
// The middleware will log all requests attributes.
router.Use(sloggin.New(logger))

// Example pong request.
router.GET("/pong", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// time="2023-04-10 14:00:00" level=INFO msg="Incoming request" status=200 method=GET path=/pong ip=127.0.0.1 latency=25.5µs user-agent=curl/7.77.0 time="2023-04-10 14:00:00"

Using custom logger sub-group

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

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

router := gin.New()

// Add the sloggin middleware to all routes.
// The middleware will log all requests attributes under a "http" group.
router.Use(sloggin.New(logger.WithGroup("http")))

// Example pong request.
router.GET("/pong", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// time=2023-04-10T14:00:0.000000+02:00 level=INFO msg="Incoming request" http.status=200 http.method=GET http.path=/pong http.ip=127.0.0.1 http.latency=20.125µs http.user-agent=curl/7.77.0 time=2023-04-10T14:00:00.000+02:00

Add logger to a single route

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

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

router := gin.New()

// Example pong request.
// Add the sloggin middleware to a single routes.
router.GET("/pong", sloggin.New(logger), func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// time="2023-04-10 14:00:00" level=INFO msg="Incoming request" status=200 method=GET path=/pong ip=127.0.0.1 latency=25.5µs user-agent=curl/7.77.0 time="2023-04-10 14:00:00"

Adding custom attributes

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

// Create a slog logger, which:
//   - Logs to stdout.
logger := slog.New(slog.NewTextHandler(os.Stdout, nil)).
    With("environment", "production").
    With("server", "gin/1.9.0").
    With("server_start_time", time.Now()).
    With("gin_mode", gin.EnvGinMode)

router := gin.New()

// Add the sloggin middleware to all routes.
// The middleware will log all requests attributes.
router.Use(sloggin.New(logger))

// Example pong request.
router.GET("/pong", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// time=2023-04-10T14:00:0.000000+02:00 level=INFO msg="Incoming request" environment=production server=gin/1.9.0 gin_mode=release server_start_time=2023-04-10T10:00:00.000+02:00 status=200 method=GET path=/pong ip=127.0.0.1 latency=25.5µs user-agent=curl/7.77.0 time=2023-04-10T14:00:00.000+02:00

JSON output

import (
	"github.com/gin-gonic/gin"
	sloggin "github.com/samber/slog-gin"
	"log/slog"
)

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

router := gin.New()

// Add the sloggin middleware to all routes.
// The middleware will log all requests attributes.
router.Use(sloggin.New(logger))

// Example pong request.
router.GET("/pong", func(c *gin.Context) {
    c.String(http.StatusOK, "pong")
})

router.Run(":1234")

// output:
// {"time":"2023-04-10T14:00:0.000000+02:00","level":"INFO","msg":"Incoming request","gin_mode":"GIN_MODE","status":200,"method":"GET","path":"/pong","ip":"127.0.0.1","latency":15542,"user-agent":"curl/7.77.0","time":"2023-04-10T14:00:0.000000+02:00"}

🤝 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

alfonmga/slog-gin

slog: Gin middleware

🚀 Install

💡 Usage

Minimal

Filters

Using custom time formatters

Using custom logger sub-group

Add logger to a single route

Adding custom attributes

JSON output

🤝 Contributing

👤 Contributors

💫 Show your support

📝 License