Critical: Graceful shutdown logic is unreachable

[sgaunet]

Description

The graceful shutdown code at lines 274-278 is unreachable, meaning the server never shuts down gracefully and active connections are terminated abruptly on SIGTERM/SIGINT.

Location

http-echo.go:270-278

if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
    log.Fatalf("Could not start server: %s\n", err.Error())
}

// Lines 274-278 are unreachable
ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
defer cancel()
if err := server.Shutdown(ctx); err != nil {
    log.Printf("Server shutdown error: %s\n", err.Error())
}

Impact

• Severity: HIGH
• Active HTTP requests are terminated immediately
• No graceful connection draining
• Poor experience in container/Kubernetes environments
• Shutdown timeout configuration is unused

Root Cause

ListenAndServe() blocks until the server stops. Any error that isn't http.ErrServerClosed causes log.Fatalf() to exit the program, making lines 274-278 unreachable.

Recommended Fix

Implement proper signal handling with goroutines:

func main() {
    var h helloWorldhandler
    server := &http.Server{
        Addr:           ":8080",
        Handler:        h,
        ReadTimeout:    readTimeout,
        WriteTimeout:   writeTimeout,
        IdleTimeout:    idleTimeout,
        MaxHeaderBytes: maxHeaderBytes,
    }

    // Start server in goroutine
    go func() {
        log.Println("Starting server on :8080")
        if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
            log.Fatalf("Could not start server: %s\n", err.Error())
        }
    }()

    // Wait for interrupt signal
    quit := make(chan os.Signal, 1)
    signal.Notify(quit, os.Interrupt, syscall.SIGTERM)
    <-quit

    log.Println("Shutdown signal received, shutting down gracefully...")
    ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
    defer cancel()
    if err := server.Shutdown(ctx); err != nil {
        log.Printf("Server shutdown error: %s\n", err.Error())
    }
    log.Println("Server stopped")
}

Note: Add "os/signal" and "syscall" to imports.

Testing

• Start the server and send SIGTERM: kill -TERM <pid>
• Verify graceful shutdown message appears
• Confirm active requests complete before shutdown
• Test in Docker/Kubernetes with terminationGracePeriodSeconds

Priority

Critical - Essential for production deployments, especially in containerized environments.