From c1ce8b4688b319dda65649e9d370dd7f8170bfbc Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@docker.com>
Date: Thu, 11 May 2017 18:40:03 +0100
Subject: [PATCH] Consolidate metadata ISO writing into a single function

Used by both `metadata create` and the hyperkit runner.

Signed-off-by: Ian Campbell <ian.campbell@docker.com>
---
 src/cmd/linuxkit/metadata.go     | 22 +++++++++++++---------
 src/cmd/linuxkit/run_hyperkit.go | 13 ++-----------
 2 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/src/cmd/linuxkit/metadata.go b/src/cmd/linuxkit/metadata.go
index 82ac21a70..286c62b8a 100644
--- a/src/cmd/linuxkit/metadata.go
+++ b/src/cmd/linuxkit/metadata.go
@@ -9,6 +9,17 @@ import (
 	"github.com/rneugeba/iso9660wrap"
 )
 
+// WriteMetadataISO writes a metadata ISO file in a format usable by pkg/metadata
+func WriteMetadataISO(path string, content []byte) error {
+	outfh, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer outfh.Close()
+
+	return iso9660wrap.WriteBuffer(outfh, content, "config")
+}
+
 func metadataCreateUsage() {
 	invoked := filepath.Base(os.Args[0])
 	fmt.Printf("USAGE: %s metadata create [file.iso] [metadata]\n\n", invoked)
@@ -32,15 +43,8 @@ func metadataCreate(args []string) {
 	isoImage := args[0]
 	metadata := args[1]
 
-	outfh, err := os.OpenFile(isoImage, os.O_CREATE|os.O_WRONLY, 0644)
-	if err != nil {
-		log.Fatal("Cannot create user data ISOs", "err", err)
-	}
-	defer outfh.Close()
-
-	err = iso9660wrap.WriteBuffer(outfh, []byte(metadata), "config")
-	if err != nil {
-		log.Fatal("Cannot write user data ISO", "err", err)
+	if err := WriteMetadataISO(isoImage, []byte(metadata)); err != nil {
+		log.Fatal("Failed to write user data ISO: ", err)
 	}
 }
 
diff --git a/src/cmd/linuxkit/run_hyperkit.go b/src/cmd/linuxkit/run_hyperkit.go
index f1459c98f..17ae46d90 100644
--- a/src/cmd/linuxkit/run_hyperkit.go
+++ b/src/cmd/linuxkit/run_hyperkit.go
@@ -10,7 +10,6 @@ import (
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/moby/hyperkit/go"
-	"github.com/rneugeba/iso9660wrap"
 	"github.com/satori/go.uuid"
 )
 
@@ -56,16 +55,8 @@ func runHyperKit(args []string) {
 			}
 		}
 		isoPath = prefix + "-data.iso"
-		outfh, err := os.OpenFile(isoPath, os.O_CREATE|os.O_WRONLY, 0644)
-		if err != nil {
-			log.Fatalf("Cannot create user data ISO: %v", err)
-		}
-		err = iso9660wrap.WriteBuffer(outfh, d, "config")
-		if err != nil {
-			log.Fatalf("Cannot write user data ISO: %v", err)
-		}
-		if err = outfh.Close(); err != nil {
-			log.Fatalf("Cannot close output ISO: %v", err)
+		if err := WriteMetadataISO(isoPath, d); err != nil {
+			log.Fatalf("Cannot write user data ISO: %s", err)
 		}
 	}