From 45160b88a40171ff907224bb9fc8e7bde7b9a13e Mon Sep 17 00:00:00 2001
From: Evan Lezar <elezar@nvidia.com>
Date: Wed, 6 Apr 2022 16:18:56 +0200
Subject: [PATCH] Remove exsiting NVIDIA Container Runtime Hooks from the spec

Signed-off-by: Evan Lezar <elezar@nvidia.com>
---
 .../modifier/experimental_test.go                  | 14 ++++++--------
 .../modifier/hook_remover.go                       | 12 ++++++++++--
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/cmd/nvidia-container-runtime/modifier/experimental_test.go b/cmd/nvidia-container-runtime/modifier/experimental_test.go
index 9e09873a..34f83bf4 100644
--- a/cmd/nvidia-container-runtime/modifier/experimental_test.go
+++ b/cmd/nvidia-container-runtime/modifier/experimental_test.go
@@ -231,7 +231,7 @@ func TestExperimentalModifier(t *testing.T) {
 			},
 		},
 		{
-			description: "modification fails for existing nvidia-container-runtime-hook",
+			description: "modification removes existing nvidia-container-runtime-hook",
 			spec: &specs.Spec{
 				Hooks: &specs.Hooks{
 					Prestart: []specs.Hook{
@@ -254,20 +254,19 @@ func TestExperimentalModifier(t *testing.T) {
 					return hooks, nil
 				},
 			},
-			expectedError: fmt.Errorf("nvidia-container-runtime-hook already exists"),
 			expectedSpec: &specs.Spec{
 				Hooks: &specs.Hooks{
 					Prestart: []specs.Hook{
 						{
-							Path: "/path/to/nvidia-container-runtime-hook",
-							Args: []string{"/path/to/nvidia-container-runtime-hook", "prestart"},
+							Path: "/hook/b",
+							Args: []string{"/hook/b", "argb"},
 						},
 					},
 				},
 			},
 		},
 		{
-			description: "modification fails for existing nvidia-container-toolkit",
+			description: "modification removes existing nvidia-container-toolkit",
 			spec: &specs.Spec{
 				Hooks: &specs.Hooks{
 					Prestart: []specs.Hook{
@@ -290,13 +289,12 @@ func TestExperimentalModifier(t *testing.T) {
 					return hooks, nil
 				},
 			},
-			expectedError: fmt.Errorf("nvidia-container-toolkit already exists"),
 			expectedSpec: &specs.Spec{
 				Hooks: &specs.Hooks{
 					Prestart: []specs.Hook{
 						{
-							Path: "/path/to/nvidia-container-toolkit",
-							Args: []string{"/path/to/nvidia-container-toolkit", "prestart"},
+							Path: "/hook/b",
+							Args: []string{"/hook/b", "argb"},
 						},
 					},
 				},
diff --git a/cmd/nvidia-container-runtime/modifier/hook_remover.go b/cmd/nvidia-container-runtime/modifier/hook_remover.go
index 7df4b2f1..16fe82d4 100644
--- a/cmd/nvidia-container-runtime/modifier/hook_remover.go
+++ b/cmd/nvidia-container-runtime/modifier/hook_remover.go
@@ -17,7 +17,6 @@
 package modifier
 
 import (
-	"fmt"
 	"path/filepath"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
@@ -46,10 +45,19 @@ func (m nvidiaContainerRuntimeHookRemover) Modify(spec *specs.Spec) error {
 		return nil
 	}
 
+	var newPrestart []specs.Hook
+
 	for _, hook := range spec.Hooks.Prestart {
 		if isNVIDIAContainerRuntimeHook(&hook) {
-			return fmt.Errorf("spec already contains required 'prestart' hook")
+			m.logger.Debugf("Removing hook %v", hook)
+			continue
 		}
+		newPrestart = append(newPrestart, hook)
+	}
+
+	if len(newPrestart) != len(spec.Hooks.Prestart) {
+		m.logger.Debugf("Updating 'prestart' hooks to %v", newPrestart)
+		spec.Hooks.Prestart = newPrestart
 	}
 
 	return nil