From 8a626bf1ec40cd2599f13931166c4908c4d55ea9 Mon Sep 17 00:00:00 2001
From: Tom Prince <tprince@mozilla.com>
Date: Sun, 5 Jul 2020 21:07:30 -0600
Subject: [PATCH] [FIXME: revendor] Add support for squashing images.

---
 .../pkg/v1/mutate/mutate.go                   | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/vendor/github.com/google/go-containerregistry/pkg/v1/mutate/mutate.go b/vendor/github.com/google/go-containerregistry/pkg/v1/mutate/mutate.go
index cbb1bd806e..0010f868cf 100644
--- a/vendor/github.com/google/go-containerregistry/pkg/v1/mutate/mutate.go
+++ b/vendor/github.com/google/go-containerregistry/pkg/v1/mutate/mutate.go
@@ -342,6 +342,42 @@ func layerTime(layer v1.Layer, t time.Time) (v1.Layer, error) {
 	return layer, nil
 }
 
+// Squash squashes the image to a single layer
+func Squash(img v1.Image) (v1.Image, error) {
+	newImage := empty.Image
+
+	tar := Extract(img)
+	layer, err := tarball.LayerFromReader(tar)
+	if err != nil {
+		return nil, fmt.Errorf("error squashing layers: %v", err)
+	}
+
+	newImage, err = AppendLayers(newImage, layer)
+	if err != nil {
+		return nil, fmt.Errorf("appending layers: %v", err)
+	}
+
+	ocf, err := img.ConfigFile()
+	if err != nil {
+		return nil, fmt.Errorf("getting original config file: %v", err)
+	}
+
+	cf, err := newImage.ConfigFile()
+	if err != nil {
+		return nil, fmt.Errorf("setting config file: %v", err)
+	}
+
+	cfg := cf.DeepCopy()
+
+	// Copy basic config over
+	cfg.Architecture = ocf.Architecture
+	cfg.OS = ocf.OS
+	cfg.OSVersion = ocf.OSVersion
+	cfg.Config = ocf.Config
+
+	return ConfigFile(newImage, cfg)
+}
+
 // Canonical is a helper function to combine Time and configFile
 // to remove any randomness during a docker build.
 func Canonical(img v1.Image) (v1.Image, error) {