2 files changed, 92 insertions, 18 deletions
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index b41a3fa38..6c9489a08 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -174,25 +174,60 @@ func (c *Container) prepare() error {
 		return err
 	}
 
-	// Ensure container entrypoint is created (if required)
-	if c.config.CreateWorkingDir {
-		workdir, err := securejoin.SecureJoin(c.state.Mountpoint, c.WorkingDir())
-		if err != nil {
-			return errors.Wrapf(err, "error creating path to container %s working dir", c.ID())
-		}
-		rootUID := c.RootUID()
-		rootGID := c.RootGID()
+	// Make sure the workdir exists
+	if err := c.resolveWorkDir(); err != nil {
+		return err
+	}
 
-		if err := os.MkdirAll(workdir, 0755); err != nil {
-			if os.IsExist(err) {
-				return nil
+	return nil
+}
+
+// resolveWorkDir resolves the container's workdir and, depending on the
+// configuration, will create it, or error out if it does not exist.
+// Note that the container must be mounted before.
+func (c *Container) resolveWorkDir() error {
+	workdir := c.WorkingDir()
+
+	// If the specified workdir is a subdir of a volume or mount,
+	// we don't need to do anything.  The runtime is taking care of
+	// that.
+	if isPathOnVolume(c, workdir) || isPathOnBindMount(c, workdir) {
+		logrus.Debugf("Workdir %q resolved to a volume or mount", workdir)
+		return nil
+	}
+
+	_, resolvedWorkdir, err := c.resolvePath(c.state.Mountpoint, workdir)
+	if err != nil {
+		return err
+	}
+	logrus.Debugf("Workdir %q resolved to host path %q", workdir, resolvedWorkdir)
+
+	// No need to create it (e.g., `--workdir=/foo`), so let's make sure
+	// the path exists on the container.
+	if !c.config.CreateWorkingDir {
+		if _, err := os.Stat(resolvedWorkdir); err != nil {
+			if os.IsNotExist(err) {
+				return errors.Errorf("workdir %q does not exist on container %s", workdir, c.ID())
 			}
-			return errors.Wrapf(err, "error creating container %s working dir", c.ID())
+			// This might be a serious error (e.g., permission), so
+			// we need to return the full error.
+			return errors.Wrapf(err, "error detecting workdir %q on container %s", workdir, c.ID())
 		}
+	}
+
+	// Ensure container entrypoint is created (if required).
+	rootUID := c.RootUID()
+	rootGID := c.RootGID()
 
-		if err := os.Chown(workdir, rootUID, rootGID); err != nil {
-			return errors.Wrapf(err, "error chowning container %s working directory to container root", c.ID())
+	if err := os.MkdirAll(resolvedWorkdir, 0755); err != nil {
+		if os.IsExist(err) {
+			return nil
 		}
+		return errors.Wrapf(err, "error creating container %s workdir", c.ID())
+	}
+
+	if err := os.Chown(resolvedWorkdir, rootUID, rootGID); err != nil {
+		return errors.Wrapf(err, "error chowning container %s workdir to container root", c.ID())
 	}
 
 	return nil
diff --git a/libpod/container_path_resolution.go b/libpod/container_path_resolution.go
index 68f174278..805b3b947 100644
--- a/libpod/container_path_resolution.go
+++ b/libpod/container_path_resolution.go
@@ -13,6 +13,11 @@ import (
 // resolveContainerPaths resolves the container's mount point and the container
 // path as specified by the user.  Both may resolve to paths outside of the
 // container's mount point when the container path hits a volume or bind mount.
+//
+// It returns a bool, indicating whether containerPath resolves outside of
+// mountPoint (e.g., via a mount or volume), the resolved root (e.g., container
+// mount, bind mount or volume) and the resolved path on the root (absolute to
+// the host).
 func (container *Container) resolvePath(mountPoint string, containerPath string) (string, string, error) {
 	// Let's first make sure we have a path relative to the mount point.
 	pathRelativeToContainerMountPoint := containerPath
@@ -97,8 +102,8 @@ func (container *Container) resolvePath(mountPoint string, containerPath string)
 	return mountPoint, resolvedPathOnTheContainerMountPoint, nil
 }
 
-// findVolume checks if the specified container path matches a volume inside
-// the container.  It returns a matching volume or nil.
+// findVolume checks if the specified containerPath matches the destination
+// path of a Volume.  Returns a matching Volume or nil.
 func findVolume(c *Container, containerPath string) (*Volume, error) {
 	runtime := c.Runtime()
 	cleanedContainerPath := filepath.Clean(containerPath)
@@ -110,8 +115,25 @@ func findVolume(c *Container, containerPath string) (*Volume, error) {
 	return nil, nil
 }
 
-// findBindMount checks if the specified container path matches a bind mount
-// inside the container.  It returns a matching mount or nil.
+// isPathOnVolume returns true if the specified containerPath is a subdir of any
+// Volume's destination.
+func isPathOnVolume(c *Container, containerPath string) bool {
+	cleanedContainerPath := filepath.Clean(containerPath)
+	for _, vol := range c.Config().NamedVolumes {
+		if cleanedContainerPath == filepath.Clean(vol.Dest) {
+			return true
+		}
+		for dest := vol.Dest; dest != "/"; dest = filepath.Dir(dest) {
+			if cleanedContainerPath == dest {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// findBindMounts checks if the specified containerPath matches the destination
+// path of a Mount.  Returns a matching Mount or nil.
 func findBindMount(c *Container, containerPath string) *specs.Mount {
 	cleanedPath := filepath.Clean(containerPath)
 	for _, m := range c.Config().Spec.Mounts {
@@ -125,3 +147,20 @@ func findBindMount(c *Container, containerPath string) *specs.Mount {
 	}
 	return nil
 }
+
+/// isPathOnBindMount returns true if the specified containerPath is a subdir of any
+// Mount's destination.
+func isPathOnBindMount(c *Container, containerPath string) bool {
+	cleanedContainerPath := filepath.Clean(containerPath)
+	for _, m := range c.Config().Spec.Mounts {
+		if cleanedContainerPath == filepath.Clean(m.Destination) {
+			return true
+		}
+		for dest := m.Destination; dest != "/"; dest = filepath.Dir(dest) {
+			if cleanedContainerPath == dest {
+				return true
+			}
+		}
+	}
+	return false
+}