diff --git a/cmd/d2vm/build.go b/cmd/d2vm/build.go
index fcf5bad..521d035 100644
--- a/cmd/d2vm/build.go
+++ b/cmd/d2vm/build.go
@@ -39,15 +39,9 @@ var (
 			if err != nil {
 				return err
 			}
-			if debug {
-				exec.Run = exec.RunStdout
-			}
+			exec.SetDebug(debug)
 			logrus.Infof("building docker image from %s", file)
-			dargs := []string{"build", "-t", tag, "-f", file, args[0]}
-			for _, v := range buildArgs {
-				dargs = append(dargs, "--build-arg", v)
-			}
-			if err := docker.Cmd(cmd.Context(), dargs...); err != nil {
+			if err := docker.Build(cmd.Context(), tag, file, args[0], buildArgs...); err != nil {
 				return err
 			}
 			return d2vm.Convert(cmd.Context(), tag, size, password, output, format)
diff --git a/cmd/d2vm/convert.go b/cmd/d2vm/convert.go
index d3b8781..9d309ea 100644
--- a/cmd/d2vm/convert.go
+++ b/cmd/d2vm/convert.go
@@ -51,9 +51,7 @@ var (
 					return fmt.Errorf("%s already exists", output)
 				}
 			}
-			if debug {
-				exec.Run = exec.RunStdout
-			}
+			exec.SetDebug(debug)
 			if _, err := os.Stat(output); err == nil || !os.IsNotExist(err) {
 				if !force {
 					return fmt.Errorf("%s already exists", output)
@@ -61,18 +59,18 @@ var (
 			}
 			found := false
 			if !pull {
-				o, _, err := docker.CmdOut(cmd.Context(), "image", "ls", "--format={{ .Repository }}:{{ .Tag }}", img)
+				imgs, err := docker.ImageList(cmd.Context(), img)
 				if err != nil {
 					return err
 				}
-				found = strings.TrimSuffix(o, "\n") == fmt.Sprintf("%s:%s", img, tag)
+				found = len(imgs) == 1 && imgs[0] == fmt.Sprintf("%s:%s", img, tag)
 				if found {
 					logrus.Infof("using local image %s:%s", img, tag)
 				}
 			}
 			if pull || !found {
 				logrus.Infof("pulling image %s", img)
-				if err := docker.Cmd(cmd.Context(), "image", "pull", img); err != nil {
+				if err := docker.Pull(cmd.Context(), img); err != nil {
 					return err
 				}
 			}
diff --git a/convert.go b/convert.go
index 8ecad8a..8852979 100644
--- a/convert.go
+++ b/convert.go
@@ -56,10 +56,10 @@ func Convert(ctx context.Context, img string, size int64, password string, outpu
 		return err
 	}
 	logrus.Infof("building kernel enabled image")
-	if err := docker.Cmd(ctx, "image", "build", "-t", imgUUID, "-f", p, dir); err != nil {
+	if err := docker.Build(ctx, imgUUID, p, dir); err != nil {
 		return err
 	}
-	defer docker.Cmd(ctx, "image", "rm", imgUUID)
+	defer docker.Remove(ctx, imgUUID)
 
 	logrus.Infof("creating vm image")
 	b, err := NewBuilder(ctx, tmpPath, imgUUID, "", size, r, format)
diff --git a/docker_image_test.go b/docker_image_test.go
index 4a7d5da..e8a6265 100644
--- a/docker_image_test.go
+++ b/docker_image_test.go
@@ -132,7 +132,7 @@ COPY hostname /etc/
 RUN rm -rf /etc/apk
 `
 	)
-	exec.Run = exec.RunStdout
+	exec.SetDebug(true)
 	tmp := filepath.Join(os.TempDir(), "d2vm-tests", "image-flatten")
 	require.NoError(t, os.MkdirAll(tmp, perm))
 	defer os.RemoveAll(tmp)
@@ -140,12 +140,9 @@ RUN rm -rf /etc/apk
 	require.NoError(t, os.WriteFile(filepath.Join(tmp, "hostname"), []byte("d2vm-flatten-test"), perm))
 	require.NoError(t, os.WriteFile(filepath.Join(tmp, "resolv.conf"), []byte("nameserver 8.8.8.8"), perm))
 	require.NoError(t, os.WriteFile(filepath.Join(tmp, "Dockerfile"), []byte(dockerfile), perm))
-	require.NoError(t, docker.Cmd(ctx, "image", "build", "-t", img, tmp))
-	defer docker.Cmd(ctx, "image", "rm", img)
+	require.NoError(t, docker.Build(ctx, img, "", tmp))
+	defer docker.Remove(ctx, img)
 
-	// imgTar := filepath.Join(tmp, img+".tar")
-	// require.NoError(t, docker.Cmd(ctx, "image", "save", img, "-o", imgTar))
-	//
 	imgTmp := filepath.Join(tmp, "image")
 
 	i, err := NewImage(ctx, img, imgTmp)
diff --git a/pkg/docker/docker.go b/pkg/docker/docker.go
index 1ea32ee..6b44a62 100644
--- a/pkg/docker/docker.go
+++ b/pkg/docker/docker.go
@@ -15,8 +15,10 @@
 package docker
 
 import (
+	"bufio"
 	"context"
 	_ "embed"
+	"path/filepath"
 	"strings"
 
 	"go.linka.cloud/d2vm/pkg/exec"
@@ -35,3 +37,36 @@ func Cmd(ctx context.Context, args ...string) error {
 func CmdOut(ctx context.Context, args ...string) (string, string, error) {
 	return exec.RunOut(ctx, "docker", args...)
 }
+
+func Build(ctx context.Context, tag, dockerfile, dir string, buildArgs ...string) error {
+	if dockerfile == "" {
+		dockerfile = filepath.Join(dir, "Dockerfile")
+	}
+	args := []string{"image", "build", "-t", tag, "-f", dockerfile}
+	for _, v := range buildArgs {
+		args = append(args, "--build-arg", v)
+	}
+	args = append(args, dir)
+	return Cmd(ctx, args...)
+}
+
+func Remove(ctx context.Context, tag string) error {
+	return Cmd(ctx, "image", "rm", tag)
+}
+
+func ImageList(ctx context.Context, tag string) ([]string, error) {
+	o, _, err := CmdOut(ctx, "image", "ls", "--format={{ .Repository }}:{{ .Tag }}", tag)
+	if err != nil {
+		return nil, err
+	}
+	s := bufio.NewScanner(strings.NewReader(o))
+	var imgs []string
+	for s.Scan() {
+		imgs = append(imgs, s.Text())
+	}
+	return imgs, s.Err()
+}
+
+func Pull(ctx context.Context, tag string) error {
+	return Cmd(ctx, "image", "pull", tag)
+}
diff --git a/pkg/exec/exec.go b/pkg/exec/exec.go
index 5231cb9..35b33fb 100644
--- a/pkg/exec/exec.go
+++ b/pkg/exec/exec.go
@@ -29,6 +29,14 @@ var (
 	CommandContext = exec.CommandContext
 )
 
+func SetDebug(debug bool) {
+	if debug {
+		Run = RunStdout
+	} else {
+		Run = RunNoOut
+	}
+}
+
 func RunStdout(ctx context.Context, c string, args ...string) error {
 	cmd := exec.CommandContext(ctx, c, args...)
 	cmd.Stdout = os.Stdout