feat: better error handling for sys kill signals

errors/errors.go

@@ -3,6 +3,15 @@ package errors
 import (
 	"errors"
 	"fmt"
+	"os"
+	"syscall"
+)
+
+const (
+	ExitCodeSigTerm = 128 + int(syscall.SIGTERM)
+	ExitCodeSighup  = 128 + int(syscall.SIGHUP)
+	ExitCodeSigint  = 128 + int(syscall.SIGINT)
+	ExitCodeSigquit = 128 + int(syscall.SIGQUIT)
 )
 
 var (
@@ -22,6 +31,10 @@ var (
 	ErrInvalidRequestParams = errors.New("invalid request params")
 	ErrSourceIsParent       = errors.New("source is parent")
 	ErrRootUserDeletion     = errors.New("user with id 1 can't be deleted")
+	ErrSigTerm              = errors.New("exit on signal: sigterm")
+	ErrSighup               = errors.New("exit on signal: sighup")
+	ErrSigint               = errors.New("exit on signal: sigint")
+	ErrSigquit              = errors.New("exit on signal: sigquit")
 )
 
 type ErrShortPassword struct {
@@ -31,3 +44,44 @@ type ErrShortPassword struct {
 func (e ErrShortPassword) Error() string {
 	return fmt.Sprintf("password is too short, minimum length is %d", e.MinimumLength)
 }
+
+// GetExitCode returns the exit code for a given error.
+func GetExitCode(err error) int {
+	if err == nil {
+		return 0
+	}
+
+	exitCodeMap := map[error]int{
+		ErrSigTerm: ExitCodeSigTerm,
+		ErrSighup:  ExitCodeSighup,
+		ErrSigint:  ExitCodeSigint,
+		ErrSigquit: ExitCodeSigquit,
+	}
+
+	for e, code := range exitCodeMap {
+		if errors.Is(err, e) {
+			return code
+		}
+	}
+
+	if exitErr, ok := err.(interface{ ExitCode() int }); ok {
+		return exitErr.ExitCode()
+	}
+
+	var pathErr *os.PathError
+	if errors.As(err, &pathErr) {
+		return 1
+	}
+
+	var syscallErr *os.SyscallError
+	if errors.As(err, &syscallErr) {
+		return 1
+	}
+
+	var errno syscall.Errno
+	if errors.As(err, &errno) {
+		return 1
+	}
+
+	return 1
+}