Merge pull request #36586 from kolyshkin/do-not-panic

ExportContainer: do not panic

container/archive.go

@@ -6,6 +6,7 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/system"
+	"github.com/pkg/errors"
 )
 
 // ResolvePath resolves the given path in the container to a resource on the
@@ -13,6 +14,9 @@ import (
 // the absolute path to the resource relative to the container's rootfs, and
 // an error if the path points to outside the container's rootfs.
 func (container *Container) ResolvePath(path string) (resolvedPath, absPath string, err error) {
+	if container.BaseFS == nil {
+		return "", "", errors.New("ResolvePath: BaseFS of container " + container.ID + " is unexpectedly nil")
+	}
 	// Check if a drive letter supplied, it must be the system drive. No-op except on Windows
 	path, err = system.CheckSystemDriveAndRemoveDriveLetter(path, container.BaseFS)
 	if err != nil {
@@ -45,6 +49,9 @@ func (container *Container) ResolvePath(path string) (resolvedPath, absPath stri
 // resolved to a path on the host corresponding to the given absolute path
 // inside the container.
 func (container *Container) StatPath(resolvedPath, absPath string) (stat *types.ContainerPathStat, err error) {
+	if container.BaseFS == nil {
+		return nil, errors.New("StatPath: BaseFS of container " + container.ID + " is unexpectedly nil")
+	}
 	driver := container.BaseFS
 
 	lstat, err := driver.Lstat(resolvedPath)

container/container.go

@@ -311,6 +311,9 @@ func (container *Container) SetupWorkingDirectory(rootIDs idtools.IDPair) error
 //       symlinking to a different path) between using this method and using the
 //       path. See symlink.FollowSymlinkInScope for more details.
 func (container *Container) GetResourcePath(path string) (string, error) {
+	if container.BaseFS == nil {
+		return "", errors.New("GetResourcePath: BaseFS of container " + container.ID + " is unexpectedly nil")
+	}
 	// IMPORTANT - These are paths on the OS where the daemon is running, hence
 	// any filepath operations must be done in an OS agnostic way.
 	r, e := container.BaseFS.ResolveScopedPath(path, false)

daemon/export.go

@@ -61,12 +61,12 @@ func (daemon *Daemon) containerExport(container *container.Container) (arch io.R
 		}
 	}()
 
-	_, err = rwlayer.Mount(container.GetMountLabel())
+	basefs, err := rwlayer.Mount(container.GetMountLabel())
 	if err != nil {
 		return nil, err
 	}
 
-	archive, err := archivePath(container.BaseFS, container.BaseFS.Path(), &archive.TarOptions{
+	archive, err := archivePath(basefs, basefs.Path(), &archive.TarOptions{
 		Compression: archive.Uncompressed,
 		UIDMaps:     daemon.idMappings.UIDs(),
 		GIDMaps:     daemon.idMappings.GIDs(),

daemon/oci_linux.go

@@ -705,6 +705,9 @@ func setMounts(daemon *Daemon, s *specs.Spec, c *container.Container, mounts []c
 }
 
 func (daemon *Daemon) populateCommonSpec(s *specs.Spec, c *container.Container) error {
+	if c.BaseFS == nil {
+		return errors.New("populateCommonSpec: BaseFS of container " + c.ID + " is unexpectedly nil")
+	}
 	linkedEnv, err := daemon.setupLinkedContainers(c)
 	if err != nil {
 		return err

daemon/oci_windows.go

@@ -221,6 +221,9 @@ func (daemon *Daemon) createSpec(c *container.Container) (*specs.Spec, error) {
 
 // Sets the Windows-specific fields of the OCI spec
 func (daemon *Daemon) createSpecWindowsFields(c *container.Container, s *specs.Spec, isHyperV bool) error {
+	if c.BaseFS == nil {
+		return errors.New("createSpecWindowsFields: BaseFS of container " + c.ID + " is unexpectedly nil")
+	}
 	if len(s.Process.Cwd) == 0 {
 		// We default to C:\ to workaround the oddity of the case that the
 		// default directory for cmd running as LocalSystem (or