new "image" mount type

Add a new "image" mount type to `--mount`.  The source of the mount is
the name or ID of an image.  The destination is the path inside the
container.  Image mounts further support an optional `rw,readwrite`
parameter which if set to "true" will yield the mount writable inside
the container.  Note that no changes are propagated to the image mount
on the host (which in any case is read only).

Mounts are overlay mounts.  To support read-only overlay mounts, vendor
a non-release version of Buildah.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/libpod/container_validate.go b/libpod/container_validate.go
index b78168cd1..68cc095b7 100644
--- a/libpod/container_validate.go
+++ b/libpod/container_validate.go
@@ -88,7 +88,7 @@ func (c *Container) validate() error {
 		return errors.Wrapf(define.ErrInvalidArg, "cannot add to /etc/hosts if using image's /etc/hosts")
 	}
 
-	// Check named volume and overlay volumes destination conflits
+	// Check named volume, overlay volume and image volume destination conflits
 	destinations := make(map[string]bool)
 	for _, vol := range c.config.NamedVolumes {
 		// Don't check if they already exist.
@@ -106,6 +106,14 @@ func (c *Container) validate() error {
 		}
 		destinations[vol.Dest] = true
 	}
+	for _, vol := range c.config.ImageVolumes {
+		// Don't check if they already exist.
+		// If they don't we will automatically create them.
+		if _, ok := destinations[vol.Dest]; ok {
+			return errors.Wrapf(define.ErrInvalidArg, "two volumes found with destination %s", vol.Dest)
+		}
+		destinations[vol.Dest] = true
+	}
 
 	return nil
 }