Kill Firecracker if SendCtrlAltDel failed

infrastructure/firecracker/provider.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/url"
+	"os"
 
 	"github.com/go-openapi/strfmt"
 	"github.com/sirupsen/logrus"
@@ -155,22 +156,26 @@ func (p *fcProvider) Delete(ctx context.Context, id string) error {
 	_, err = client.CreateSyncAction(ctx, &fcmodels.InstanceActionInfo{
 		ActionType: firecracker.String("SendCtrlAltDel"),
 	})
-	if err != nil {
-		// What errors do we want to ignore?
-		// Example:
-		// * net/url.Error happens if the VM is not running or the socket file
-		//   is not there, so we can delete the VM.
-		if errors.Is(err, &url.Error{}) {
-			logger.Info("microvm is not running")
-		} else {
+	if err == nil {
+		return nil
+	}
+
+	// What errors do we want to ignore?
+	// Example:
+	// * net/url.Error happens if the VM is not running or the socket file
+	//   is not there, so we can delete the VM.
+	if errors.Is(err, &url.Error{}) {
+		logger.Info("microvm is not running")
+	} else if pid, pidErr := vmState.PID(); pidErr != nil {
+		logger.Infof("sending SIGINT to %d", pid)
+
+		if sigErr := process.SendSignal(pid, os.Interrupt); sigErr != nil {
 			return fmt.Errorf("failed to create halt action: %w", err)
 		}
+	} else {
+		return fmt.Errorf("failed to create halt action: %w", err)
 	}
 
-	// It's strange to call it delete, it terminates the vm, but by the nature of
-	// firecracker, if it's terminated, it's not there anymore, only the
-	// resources we created before, but we have steps for them.
-
 	logger.Info("deleted microvm")
 
 	return nil

pkg/process/process.go

@@ -42,3 +42,21 @@ func Exists(pid int) (bool, error) {
 
 	return exists, nil
 }
+
+// SendSignal sends a 'sig' signal to 'pid' process.
+func SendSignal(pid int, sig os.Signal) error {
+	proc, err := os.FindProcess(pid)
+	if err != nil {
+		return fmt.Errorf("unable to find process (%d): %w", pid, err)
+	}
+
+	if err := proc.Signal(os.Interrupt); err != nil {
+		return fmt.Errorf(
+			"unable to send signal to process (%s): %w",
+			sig.String(),
+			err,
+		)
+	}
+
+	return nil
+}