From a5e5d42368c38724088247761910580d8420f9c3 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ijc@docker.com>
Date: Mon, 20 Nov 2017 15:14:58 +0000
Subject: [PATCH] Move metadata ISO creation to common code

This code was identical in the QEMU and HyperKit cases. Move it to util.go and
wrap it in a function, with minimal changes for returning an error.

Signed-off-by: Ian Campbell <ijc@docker.com>
---
 src/cmd/linuxkit/run_hyperkit.go | 19 ++++---------------
 src/cmd/linuxkit/run_qemu.go     | 19 ++++---------------
 src/cmd/linuxkit/util.go         | 24 ++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/src/cmd/linuxkit/run_hyperkit.go b/src/cmd/linuxkit/run_hyperkit.go
index c684158c2..2b3657766 100644
--- a/src/cmd/linuxkit/run_hyperkit.go
+++ b/src/cmd/linuxkit/run_hyperkit.go
@@ -141,22 +141,11 @@ func runHyperKit(args []string) {
 		log.Fatalf("Could not create state directory: %v", err)
 	}
 
-	if *data != "" {
-		var d []byte
-		if _, err := os.Stat(*data); os.IsNotExist(err) {
-			d = []byte(*data)
-		} else {
-			d, err = ioutil.ReadFile(*data)
-			if err != nil {
-				log.Fatalf("Cannot read user data: %v", err)
-			}
-		}
-		isoPath := filepath.Join(*state, "data.iso")
-		if err := WriteMetadataISO(isoPath, d); err != nil {
-			log.Fatalf("Cannot write user data ISO: %v", err)
-		}
-		isoPaths = append(isoPaths, isoPath)
+	metadataPaths, err := CreateMetadataISO(*state, *data)
+	if err != nil {
+		log.Fatalf("%v", err)
 	}
+	isoPaths = append(isoPaths, metadataPaths...)
 
 	// Create UUID for VPNKit or reuse an existing one from state dir. IP addresses are
 	// assigned to the UUID, so to get the same IP we have to store the initial UUID. If
diff --git a/src/cmd/linuxkit/run_qemu.go b/src/cmd/linuxkit/run_qemu.go
index 5510c3042..91ca75d8e 100644
--- a/src/cmd/linuxkit/run_qemu.go
+++ b/src/cmd/linuxkit/run_qemu.go
@@ -223,22 +223,11 @@ func runQemu(args []string) {
 		isoPaths = append(isoPaths, path)
 	}
 
-	if *data != "" {
-		var d []byte
-		if _, err := os.Stat(*data); os.IsNotExist(err) {
-			d = []byte(*data)
-		} else {
-			d, err = ioutil.ReadFile(*data)
-			if err != nil {
-				log.Fatalf("Cannot read user data: %v", err)
-			}
-		}
-		isoPath := filepath.Join(*state, "data.iso")
-		if err := WriteMetadataISO(isoPath, d); err != nil {
-			log.Fatalf("Cannot write user data ISO: %v", err)
-		}
-		isoPaths = append(isoPaths, isoPath)
+	metadataPaths, err := CreateMetadataISO(*state, *data)
+	if err != nil {
+		log.Fatalf("%v", err)
 	}
+	isoPaths = append(isoPaths, metadataPaths...)
 
 	for i, d := range disks {
 		id := ""
diff --git a/src/cmd/linuxkit/util.go b/src/cmd/linuxkit/util.go
index 33c665486..c47d7cefd 100644
--- a/src/cmd/linuxkit/util.go
+++ b/src/cmd/linuxkit/util.go
@@ -3,7 +3,9 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
@@ -252,3 +254,25 @@ func NewPublishedPort(publish string) (PublishedPort, error) {
 	p.Protocol = protocol
 	return p, nil
 }
+
+// CreateMetadataISO writes the provided meta data to an iso file in the given state directory
+func CreateMetadataISO(state, data string) ([]string, error) {
+	if data == "" {
+		return []string{}, nil
+	}
+
+	var d []byte
+	if _, err := os.Stat(data); os.IsNotExist(err) {
+		d = []byte(data)
+	} else {
+		d, err = ioutil.ReadFile(data)
+		if err != nil {
+			return nil, fmt.Errorf("Cannot read user data: %v", err)
+		}
+	}
+	isoPath := filepath.Join(state, "data.iso")
+	if err := WriteMetadataISO(isoPath, d); err != nil {
+		return nil, fmt.Errorf("Cannot write user data ISO: %v", err)
+	}
+	return []string{isoPath}, nil
+}