How do you handle errors in Go in a production-ready application?

In Go, error handling is based on explicit checking of the returned error value after function calls. In production-ready applications, it is important to:

• Always check errors immediately after calling a function.
• Use error wrapping (fmt.Errorf with %w) to preserve context.
• Log errors with sufficient detail, including call stacks if necessary.
• For critical errors, apply retry strategies or fallback.
• In HTTP services, return correct status codes and understandable messages.

Example of error handling with wrapping and logging:

package main

import (
    "errors"
    "fmt"
    "log"
)

func doSomething() error {
    return errors.New("original error")
}

func main() {
    err := doSomething()
    if err != nil {
        wrappedErr := fmt.Errorf("error in doSomething: %w", err)
        log.Printf("An error occurred: %v", wrappedErr)
        // Additional handling, e.g., returning the error upwards
    }
}