Implement image preseeding

This pulls in the infrastructure to build OCI bundles with Bazel and adds a loader to
load them into containerd at runtime.

Test Plan: New E2E test using a simple hello world Go image.

Bug: T793

X-Origin-Diff: phab/D585
GitOrigin-RevId: 3bc5e35a89a80a9683778ced72cc79e2d0b684ed
diff --git a/core/tests/e2e/main_test.go b/core/tests/e2e/main_test.go
index faae520..99cfdff 100644
--- a/core/tests/e2e/main_test.go
+++ b/core/tests/e2e/main_test.go
@@ -171,6 +171,37 @@
 					return fmt.Errorf("pod is not ready: %v", events.Items[0].Message)
 				}
 			})
+			testEventual(t, "Pod with preseeded image", ctx, smallTestTimeout, func(ctx context.Context) error {
+				_, err := clientSet.CoreV1().Pods("default").Create(ctx, &corev1.Pod{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "preseed-test-1",
+					},
+					Spec: corev1.PodSpec{
+						Containers: []corev1.Container{{
+							Name:            "preseed-test-1",
+							ImagePullPolicy: corev1.PullNever,
+							Image:           "bazel/core/tests/e2e/preseedtest:preseedtest",
+						}},
+						RestartPolicy: corev1.RestartPolicyNever,
+					},
+				}, metav1.CreateOptions{})
+				return err
+			})
+			testEventual(t, "Pod with preseeded image is completed", ctx, largeTestTimeout, func(ctx context.Context) error {
+				pod, err := clientSet.CoreV1().Pods("default").Get(ctx, "preseed-test-1", metav1.GetOptions{})
+				if err != nil {
+					return fmt.Errorf("failed to get pod: %w", err)
+				}
+				if pod.Status.Phase == corev1.PodSucceeded {
+					return nil
+				}
+				events, err := clientSet.CoreV1().Events("default").List(ctx, metav1.ListOptions{FieldSelector: fmt.Sprintf("involvedObject.name=%s,involvedObject.namespace=default", pod.Name)})
+				if err != nil || len(events.Items) == 0 {
+					return fmt.Errorf("pod is not ready: %v", pod.Status.Phase)
+				} else {
+					return fmt.Errorf("pod is not ready: %v", events.Items[len(events.Items)-1].Message)
+				}
+			})
 		})
 	})
 
diff --git a/core/tests/e2e/preseedtest/BUILD.bazel b/core/tests/e2e/preseedtest/BUILD.bazel
new file mode 100644
index 0000000..9536846
--- /dev/null
+++ b/core/tests/e2e/preseedtest/BUILD.bazel
@@ -0,0 +1,16 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_docker//go:image.bzl", "go_image")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/core/tests/e2e/preseedtest",
+    visibility = ["//visibility:private"],
+)
+
+go_image(
+    name = "preseedtest",
+    embed = [":go_default_library"],
+    pure = "on",
+    visibility = ["//visibility:public"],
+)
diff --git a/core/tests/e2e/preseedtest/main.go b/core/tests/e2e/preseedtest/main.go
new file mode 100644
index 0000000..ceb3898
--- /dev/null
+++ b/core/tests/e2e/preseedtest/main.go
@@ -0,0 +1,23 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello world from preseeded image")
+}