Custom Recovery behavior

Gin’s built-in gin.Recovery() middleware catches any panic that happens while handling a request, writes a 500 response, and keeps the server running. When you need to control what happens on recovery — for example to report the panic to the user, save it to a database, or send it to an error-tracking service — use gin.CustomRecovery() instead.

gin.CustomRecovery() takes a handler with the signature func(c *gin.Context, recovered any). The recovered value is whatever was passed to panic(). Inside the handler you decide how to respond, then call c.AbortWithStatus() (or another abort method) so the remaining handlers are skipped.

package main

import (
  "fmt"
  "net/http"

  "github.com/gin-gonic/gin"
)

func main() {
  // Creates a router without any middleware by default
  r := gin.New()

  // Global middleware
  // Logger middleware will write the logs to gin.DefaultWriter even if you set with GIN_MODE=release.
  // By default gin.DefaultWriter = os.Stdout
  r.Use(gin.Logger())

  // Recovery middleware recovers from any panics and writes a 500 if there was one.
  r.Use(gin.CustomRecovery(func(c *gin.Context, recovered any) {
    if err, ok := recovered.(string); ok {
      c.String(http.StatusInternalServerError, fmt.Sprintf("error: %s", err))
    }
    c.AbortWithStatus(http.StatusInternalServerError)
  }))

  r.GET("/panic", func(c *gin.Context) {
    // panic with a string -- the custom middleware could save this to a database or report it to the user
    panic("foo")
  })

  r.GET("/", func(c *gin.Context) {
    c.String(http.StatusOK, "ohai")
  })

  // Listen and serve on 0.0.0.0:8080
  r.Run(":8080")
}

Try it

# Triggers the panic; the custom recovery handler returns the message
curl http://localhost:8080/panic
# => error: foo

# A normal request still works
curl http://localhost:8080/
# => ohai

Custom Recovery behavior

Try it

See also