@@ -2,7 +2,12 @@ package main

 import (

 	"fmt"

+	"io/ioutil"

+	"net/http"

+	"net/http/httptest"

+	"os"

 	"os/exec"

+	"path"

 	"strconv"

 	"strings"

 	"testing"

@@ -97,3 +102,120 @@ func getContainerCount() (int, error) {

 	}

 	return 0, fmt.Errorf("couldn't find the Container count in the output")

 }

+

+type FakeContext struct {

+	Dir string

+}

+

+func (f *FakeContext) Add(file, content string) error {

+	filepath := path.Join(f.Dir, file)

+	dirpath := path.Dir(filepath)

+	if dirpath != "." {

+		if err := os.MkdirAll(dirpath, 0755); err != nil {

+			return err

+		}

+	}

+	return ioutil.WriteFile(filepath, []byte(content), 0644)

+}

+

+func (f *FakeContext) Delete(file string) error {

+	filepath := path.Join(f.Dir, file)

+	return os.RemoveAll(filepath)

+}

+

+func (f *FakeContext) Close() error {

+	return os.RemoveAll(f.Dir)

+}

+

+func fakeContext(dockerfile string, files map[string]string) (*FakeContext, error) {

+	tmp, err := ioutil.TempDir("", "fake-context")

+	if err != nil {

+		return nil, err

+	}

+	ctx := &FakeContext{tmp}

+	for file, content := range files {

+		if err := ctx.Add(file, content); err != nil {

+			ctx.Close()

+			return nil, err

+		}

+	}

+	if err := ctx.Add("Dockerfile", dockerfile); err != nil {

+		ctx.Close()

+		return nil, err

+	}

+	return ctx, nil

+}

+

+type FakeStorage struct {

+	*FakeContext

+	*httptest.Server

+}

+

+func (f *FakeStorage) Close() error {

+	f.Server.Close()

+	return f.FakeContext.Close()

+}

+

+func fakeStorage(files map[string]string) (*FakeStorage, error) {

+	tmp, err := ioutil.TempDir("", "fake-storage")

+	if err != nil {

+		return nil, err

+	}

+	ctx := &FakeContext{tmp}

+	for file, content := range files {

+		if err := ctx.Add(file, content); err != nil {

+			ctx.Close()

+			return nil, err

+		}

+	}

+	handler := http.FileServer(http.Dir(ctx.Dir))

+	server := httptest.NewServer(handler)

+	return &FakeStorage{

+		FakeContext: ctx,

+		Server:      server,

+	}, nil

+}

+

+func inspectField(name, field string) (string, error) {

+	format := fmt.Sprintf("{{.%s}}", field)

+	inspectCmd := exec.Command(dockerBinary, "inspect", "-f", format, name)

+	out, exitCode, err := runCommandWithOutput(inspectCmd)

+	if err != nil || exitCode != 0 {

+		return "", fmt.Errorf("failed to inspect %s: %s", name, out)

+	}

+	return strings.TrimSpace(out), nil

+}

+

+func getIDByName(name string) (string, error) {

+	return inspectField(name, "Id")

+}

+

+func buildImage(name, dockerfile string, useCache bool) (string, error) {

+	args := []string{"build", "-t", name}

+	if !useCache {

+		args = append(args, "--no-cache")

+	}

+	args = append(args, "-")

+	buildCmd := exec.Command(dockerBinary, args...)

+	buildCmd.Stdin = strings.NewReader(dockerfile)

+	out, exitCode, err := runCommandWithOutput(buildCmd)

+	if err != nil || exitCode != 0 {

+		return "", fmt.Errorf("failed to build the image: %s", out)

+	}

+	return getIDByName(name)

+}

+

+func buildImageFromContext(name string, ctx *FakeContext, useCache bool) (string, error) {

+	args := []string{"build", "-t", name}

+	if !useCache {

+		args = append(args, "--no-cache")

+	}

+	args = append(args, ".")

+	buildCmd := exec.Command(dockerBinary, args...)

+	buildCmd.Dir = ctx.Dir

+	out, exitCode, err := runCommandWithOutput(buildCmd)

+	if err != nil || exitCode != 0 {

+		return "", fmt.Errorf("failed to build the image: %s", out)

+	}

+	return getIDByName(name)

+}