Go Panic Proof

go-panic-proof is a Go package that provides middleware for recovering from panics in both HTTP and gRPC servers. This middleware helps ensure that server doesn't crash when an unexpected panic occurs, logging the error and providing an appropriate response.

Features

• Recover from panics in HTTP handlers.
• Recover from panics in gRPC service methods.
• Logs the panic details along with the stack trace for debugging.
• Responds with 500 Internal Server Error for HTTP, ensuring clients are informed about the issue.

2024/12/18 15:32:45 Recovered from panic in gRPC method /service/SomeMethod: something went wrong!
Stack Trace: 
goroutine 10 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
	/usr/local/go/src/runtime/debug/stack.go:24 +0x88
github.com/srahkmli/go-panic-proof.RecoverInterceptor.func1(0x1f7cae0, 0x0, 0x1f7cae0, 0x0, 0x7fddc35d19b0)
	/project/go-panic-proof/grpc.go:23 +0xd3
google.golang.org/grpc.(*Server).processUnaryRPC(0xc0004db5e0, 0x7fddc35d1928, 0x1f9b960, 0xc0004d7030, 0xc00023bc00, 0x1f7cb80, 0x0, 0x0, 0x0)
	/project/go/pkg/mod/google.golang.org/grpc@v1.42.0/server.go:1281 +0x45b
...

Installation

To install the go-panic-proof package, run the following command in Go project:

go get github.com/srahkmli/go-panic-proof

Overview

HTTPRecover

• Description: A simple middleware that recovers from panics, logs the error, and sends a default 500 Internal Server Error response.
• Key Features:
  • Logs the panic error and stack trace.
  • Responds with a fixed error message ("Internal Server Error") and HTTP status code (500).
• Use Case: Suitable for applications requiring a straightforward panic recovery mechanism without customization.

Example Usage:

http.Handle("/example", HTTPRecover(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    panic("example panic")
})))

---

HTTPRecoverWithHandler

• Description: A flexible middleware that allows custom handling of errors via a user-provided HTTPErrorHandler function.
• Key Features:
  • Accepts an HTTPErrorHandler function for customizable error responses.
  • Provides a fallback behavior similar to HTTPRecover if no handler is specified.
• Use Case: Ideal for applications requiring detailed and tailored error responses or additional error-handling logic, such as sending alerts or metrics.

Example Usage:

customHandler := func(w http.ResponseWriter, r *http.Request, err interface{}) {
    log.Printf("Custom handler: panic %v", err)
    http.Error(w, "Something went wrong", http.StatusInternalServerError)
}

http.Handle("/example", HTTPRecoverWithHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    panic("example panic")
}), customHandler))

• Use HTTPRecover for simple applications that do not require custom error handling.

• Use HTTPRecoverWithHandler when you need to provide detailed error responses or additional error-handling logic. The additional flexibility ensures the middleware can adapt to complex application requirements.

---

Differences

Aspect	HTTPRecover	HTTPRecoverWithHandler
Error Handling	Fixed behavior: log + 500 Internal Server Error.	Customizable via HTTPErrorHandler.
Flexibility	Minimal flexibility.	Highly flexible due to user-provided handler.
Custom Error Output	Not supported.	Fully supported via the handler.
Default Fallback	Logs the error and responds with 500.	Logs the error and responds with 500 if no handler.

---