Fix owner of files uploaded to docker container run as non-root.

builder/docker/communicator.go

@@ -23,6 +23,7 @@ type Communicator struct {
 	ContainerDir  string
 	Version       *version.Version
 	Config        *Config
+	containerUser *string
 	lock          sync.Mutex
 }
 
@@ -154,6 +155,10 @@ func (c *Communicator) uploadFile(dst string, src io.Reader, fi *os.FileInfo) er
 		return fmt.Errorf("Failed to upload to '%s' in container: %s. %s.", dst, stderrOut, err)
 	}
 
+	if err := c.fixDestinationOwner(dst); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -207,6 +212,10 @@ func (c *Communicator) UploadDir(dst string, src string, exclude []string) error
 		return fmt.Errorf("Failed to upload to '%s' in container: %s. %s.", dst, stderrOut, err)
 	}
 
+	if err := c.fixDestinationOwner(dst); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -310,3 +319,70 @@ func (c *Communicator) run(cmd *exec.Cmd, remote *packer.RemoteCmd, stdin io.Wri
 	// Set the exit status which triggers waiters
 	remote.SetExited(exitStatus)
 }
+
+// TODO Workaround for #5307. Remove once #5409 is fixed.
+func (c *Communicator) fixDestinationOwner(destination string) error {
+	if c.containerUser == nil {
+		containerUser, err := c.discoverContainerUser()
+		if err != nil {
+			return err
+		}
+		c.containerUser = &containerUser
+	}
+
+	if *c.containerUser != "" {
+		chownArgs := []string{
+			"docker", "exec", "--user", "root", c.ContainerID, "/bin/sh", "-c",
+			fmt.Sprintf("chown -R %s %s", *c.containerUser, destination),
+		}
+		if _, err := c.runLocalCommand(chownArgs[0], chownArgs[1:]...); err != nil {
+			return fmt.Errorf("Failed to set owner of the uploaded file: %s", err)
+		}
+	}
+
+	return nil
+}
+
+func (c *Communicator) discoverContainerUser() (string, error) {
+	var err error
+	var stdout []byte
+	inspectArgs := []string{"docker", "inspect", "--format", "{{.Config.User}}", c.ContainerID}
+	if stdout, err = c.runLocalCommand(inspectArgs[0], inspectArgs[1:]...); err != nil {
+		return "", fmt.Errorf("Failed to inspect the container: %s", err)
+	}
+	return strings.TrimSpace(string(stdout)), nil
+}
+
+func (c *Communicator) runLocalCommand(name string, arg ...string) (stdout []byte, err error) {
+	localCmd := exec.Command(name, arg...)
+
+	stdoutP, err := localCmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("failed to open stdout pipe, %s", err)
+	}
+
+	stderrP, err := localCmd.StderrPipe()
+	if err != nil {
+		return nil, fmt.Errorf("failed to open stderr pipe, %s", err)
+	}
+
+	if err = localCmd.Start(); err != nil {
+		return nil, fmt.Errorf("failed to start command, %s", err)
+	}
+
+	stdout, err = ioutil.ReadAll(stdoutP)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read from stdout pipe, %s", err)
+	}
+
+	stderr, err := ioutil.ReadAll(stderrP)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read from stderr pipe, %s", err)
+	}
+
+	if err := localCmd.Wait(); err != nil {
+		return nil, fmt.Errorf("%s, %s", stderr, err)
+	}
+
+	return stdout, nil
+}

builder/docker/communicator_test.go

@@ -209,6 +209,82 @@ func TestLargeDownload(t *testing.T) {
 
 }
 
+// TestUploadOwner verifies that owner of uploaded files is the user the container is running as.
+func TestUploadOwner(t *testing.T) {
+	ui := packer.TestUi(t)
+	cache := &packer.FileCache{CacheDir: os.TempDir()}
+
+	tpl, err := template.Parse(strings.NewReader(testUploadOwnerTemplate))
+	if err != nil {
+		t.Fatalf("Unable to parse config: %s", err)
+	}
+
+	if os.Getenv("PACKER_ACC") == "" {
+		t.Skip("This test is only run with PACKER_ACC=1")
+	}
+	cmd := exec.Command("docker", "-v")
+	cmd.Run()
+	if !cmd.ProcessState.Success() {
+		t.Error("docker command not found; please make sure docker is installed")
+	}
+
+	// Setup the builder
+	builder := &Builder{}
+	warnings, err := builder.Prepare(tpl.Builders["docker"].Config)
+	if err != nil {
+		t.Fatalf("Error preparing configuration %s", err)
+	}
+	if len(warnings) > 0 {
+		t.Fatal("Encountered configuration warnings; aborting")
+	}
+
+	// Setup the provisioners
+	fileProvisioner := &file.Provisioner{}
+	err = fileProvisioner.Prepare(tpl.Provisioners[0].Config)
+	if err != nil {
+		t.Fatalf("Error preparing single file upload provisioner: %s", err)
+	}
+
+	dirProvisioner := &file.Provisioner{}
+	err = dirProvisioner.Prepare(tpl.Provisioners[1].Config)
+	if err != nil {
+		t.Fatalf("Error preparing directory upload provisioner: %s", err)
+	}
+
+	shellProvisioner := &shell.Provisioner{}
+	err = shellProvisioner.Prepare(tpl.Provisioners[2].Config)
+	if err != nil {
+		t.Fatalf("Error preparing shell provisioner: %s", err)
+	}
+
+	verifyProvisioner := &shell.Provisioner{}
+	err = verifyProvisioner.Prepare(tpl.Provisioners[3].Config)
+	if err != nil {
+		t.Fatalf("Error preparing verification provisioner: %s", err)
+	}
+
+	// Add hooks so the provisioners run during the build
+	hooks := map[string][]packer.Hook{}
+	hooks[packer.HookProvision] = []packer.Hook{
+		&packer.ProvisionHook{
+			Provisioners: []packer.Provisioner{
+				fileProvisioner,
+				dirProvisioner,
+				shellProvisioner,
+				verifyProvisioner,
+			},
+			ProvisionerTypes: []string{"", "", "", ""},
+		},
+	}
+	hook := &packer.DispatchHook{Mapping: hooks}
+
+	artifact, err := builder.Run(ui, hook, cache)
+	if err != nil {
+		t.Fatalf("Error running build %s", err)
+	}
+	defer artifact.Destroy()
+}
+
 const dockerBuilderConfig = `
 {
   "builders": [
@@ -269,3 +345,40 @@ const dockerLargeBuilderConfig = `
   ]
 }
 `
+
+const testUploadOwnerTemplate = `
+{
+  "builders": [
+    {
+      "type": "docker",
+      "image": "ubuntu",
+      "discard": true,
+      "run_command": ["-d", "-i", "-t", "-u", "42", "{{.Image}}", "/bin/sh"]
+    }
+  ],
+  "provisioners": [
+    {
+      "type": "file",
+      "source": "test-fixtures/onecakes/strawberry",
+      "destination": "/tmp/strawberry-cake"
+    },
+    {
+      "type": "file",
+      "source": "test-fixtures/manycakes",
+      "destination": "/tmp/"
+    },
+    {
+      "type": "shell",
+      "inline": "touch /tmp/testUploadOwner"
+    },
+    {
+      "type": "shell",
+      "inline": [
+        "[ $(stat -c %u /tmp/strawberry-cake) -eq 42 ] || (echo 'Invalid owner of /tmp/strawberry-cake' && exit 1)",
+        "[ $(stat -c %u /tmp/testUploadOwner) -eq 42 ] || (echo 'Invalid owner of /tmp/testUploadOwner' && exit 1)",
+        "find /tmp/manycakes | xargs -n1 -IFILE /bin/sh -c '[ $(stat -c %u FILE) -eq 42 ] || (echo \"Invalid owner of FILE\" && exit 1)'"
+      ]
+    }
+  ]
+}
+`