From 1aee0c3d30424c4fffe2a39ce6e2599756d0bf41 Mon Sep 17 00:00:00 2001
From: Rolf Neugebauer <rolf.neugebauer@docker.com>
Date: Wed, 4 Oct 2017 17:59:02 +0100
Subject: [PATCH] Update Image strings before writing them out

If the YAML file contains:
  - path: etc/linuxkit.yml
    metadata: yaml
in the fil section, the image was build with content trust,
then the linuxkit.yml file image contains fully qualified
image references (including the sha256).

Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
---
 src/moby/build.go  |  2 ++
 src/moby/config.go | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/src/moby/build.go b/src/moby/build.go
index 9b5da1a9d..ef8e60ea7 100644
--- a/src/moby/build.go
+++ b/src/moby/build.go
@@ -388,6 +388,8 @@ func tarAppend(iw *tar.Writer, tr *tar.Reader) error {
 
 // this allows inserting metadata into a file in the image
 func metadata(m Moby, md string) ([]byte, error) {
+	// Make sure the Image strings are update to date with the refs
+	updateImages(&m)
 	switch md {
 	case "json":
 		return json.MarshalIndent(m, "", "    ")
diff --git a/src/moby/config.go b/src/moby/config.go
index 13a0cb0dc..49172574e 100644
--- a/src/moby/config.go
+++ b/src/moby/config.go
@@ -197,6 +197,31 @@ func extractReferences(m *Moby) error {
 	return nil
 }
 
+func updateImages(m *Moby) error {
+	if m.Kernel.ref != nil {
+		m.Kernel.Image = m.Kernel.ref.String()
+	}
+	for i, ii := range m.initRefs {
+		m.Init[i] = ii.String()
+	}
+	for _, image := range m.Onboot {
+		if image.ref != nil {
+			image.Image = image.ref.String()
+		}
+	}
+	for _, image := range m.Onshutdown {
+		if image.ref != nil {
+			image.Image = image.ref.String()
+		}
+	}
+	for _, image := range m.Services {
+		if image.ref != nil {
+			image.Image = image.ref.String()
+		}
+	}
+	return nil
+}
+
 // NewConfig parses a config file
 func NewConfig(config []byte) (Moby, error) {
 	m := Moby{}