From ef4e7c2da8f7b77a3c30d8a350b8f9948367c3f1 Mon Sep 17 00:00:00 2001
From: y_uuki <yuki.tsubo@gmail.com>
Date: Sun, 16 Jul 2017 02:24:54 +0900
Subject: [PATCH] Use Env of docker image insetad of printenv to generate
 drootenv

---
 docker/docker.go      | 17 +++++++++++++----
 docker/docker_test.go |  7 +++++++
 docker/testing.go     | 15 ++++++++++-----
 3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/docker/docker.go b/docker/docker.go
index f6bacd9..1e6bbfa 100644
--- a/docker/docker.go
+++ b/docker/docker.go
@@ -1,20 +1,22 @@
 package docker
 
 import (
+	"fmt"
 	"io"
+	"strings"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/network"
 	"github.com/docker/docker/client"
 	"github.com/pkg/errors"
-	"golang.org/x/net/context" // docker/docker don't use 'context' as standard package.
-
 	"github.com/yuuki/droot/environ"
+	"golang.org/x/net/context" // docker/docker don't use 'context' as standard package.
 )
 
 // dockerAPI is an interface for stub testing.
 type dockerAPI interface {
+	ImageInspectWithRaw(ctx context.Context, imageID string) (types.ImageInspect, []byte, error)
 	ContainerCreate(ctx context.Context, config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, containerName string) (container.ContainerCreateCreatedBody, error)
 	ContainerStart(ctx context.Context, containerID string, options types.ContainerStartOptions) error
 	ContainerWait(ctx context.Context, containerID string) (int64, error)
@@ -44,10 +46,17 @@ func New() (*Client, error) {
 func (c *Client) ExportImage(imageID string) (io.ReadCloser, error) {
 	ctx := context.Background()
 
+	image, _, err := c.docker.ImageInspectWithRaw(ctx, imageID)
+	if err != nil {
+		return nil, errors.Wrapf(err, "Failed to inspect image imageID:%s", imageID)
+	}
+
+	//Put drootenv file into the filesystem.
+	cmd := fmt.Sprintf("echo \"%s\" > %s", strings.Join(image.ContainerConfig.Env, "\n"), environ.DROOT_ENV_FILE_PATH)
 	container, err := c.docker.ContainerCreate(ctx, &container.Config{
 		Image:      imageID,
-		Entrypoint: []string{"/bin/sh"}, // Clear the exising entrypoint
-		Cmd:        []string{"-c", "printenv", ">", environ.DROOT_ENV_FILE_PATH},
+		Entrypoint: []string{""}, // Clear the exising entrypoint
+		Cmd:        []string{"/bin/sh", "-c", cmd},
 	}, nil, nil, "")
 	if err != nil {
 		return nil, errors.Wrapf(err, "Failed to create container imageID:%s", imageID)
diff --git a/docker/docker_test.go b/docker/docker_test.go
index e7208bb..c155142 100644
--- a/docker/docker_test.go
+++ b/docker/docker_test.go
@@ -17,6 +17,13 @@ func TestExportImage(t *testing.T) {
 	containerID := "container ID"
 
 	fakeClient := &fakeDocker{
+		FakeImageInspectWithRaw: func(ctx context.Context, imageID string) (types.ImageInspect, []byte, error) {
+			return types.ImageInspect{
+				ContainerConfig: &container.Config{
+					Env: []string{"PATH=/usr/bin:/sbin:/bin"},
+				},
+			}, []byte{}, nil
+		},
 		FakeContainerCreate: func(ctx context.Context, config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, containerName string) (container.ContainerCreateCreatedBody, error) {
 			return container.ContainerCreateCreatedBody{ID: containerID}, nil
 		},
diff --git a/docker/testing.go b/docker/testing.go
index 8b7a1a7..5ef2fae 100644
--- a/docker/testing.go
+++ b/docker/testing.go
@@ -11,11 +11,16 @@ import (
 
 type fakeDocker struct {
 	dockerAPI
-	FakeContainerCreate func(ctx context.Context, config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, containerName string) (container.ContainerCreateCreatedBody, error)
-	FakeContainerStart  func(ctx context.Context, containerID string, options types.ContainerStartOptions) error
-	FakeContainerWait   func(ctx context.Context, containerID string) (int64, error)
-	FakeContainerExport func(ctx context.Context, containerID string) (io.ReadCloser, error)
-	FakeContainerRemove func(ctx context.Context, containerID string, options types.ContainerRemoveOptions) error
+	FakeImageInspectWithRaw func(ctx context.Context, imageID string) (types.ImageInspect, []byte, error)
+	FakeContainerCreate     func(ctx context.Context, config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig, containerName string) (container.ContainerCreateCreatedBody, error)
+	FakeContainerStart      func(ctx context.Context, containerID string, options types.ContainerStartOptions) error
+	FakeContainerWait       func(ctx context.Context, containerID string) (int64, error)
+	FakeContainerExport     func(ctx context.Context, containerID string) (io.ReadCloser, error)
+	FakeContainerRemove     func(ctx context.Context, containerID string, options types.ContainerRemoveOptions) error
+}
+
+func (d *fakeDocker) ImageInspectWithRaw(ctx context.Context, imageID string) (types.ImageInspect, []byte, error) {
+	return d.FakeImageInspectWithRaw(ctx, imageID)
 }
 
 func (d *fakeDocker) ContainerRemove(ctx context.Context, containerID string, options types.ContainerRemoveOptions) error {