container: move volume chown after spec generation

move the chown for newly created volumes after the spec generation so
the correct UID/GID are known.

Closes: https://github.com/containers/libpod/issues/5698

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

5 files changed, 103 insertions, 7 deletions

diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index e86512569..7a547e565 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -1015,6 +1015,12 @@ func (c *Container) init(ctx context.Context, retainRetries bool) error {
 		return err
 	}
 
+	for _, v := range c.config.NamedVolumes {
+		if err := c.chownVolume(v.Name); err != nil {
+			return err
+		}
+	}
+
 	// With the spec complete, do an OCI create
 	if err := c.ociRuntime.CreateContainer(c, nil); err != nil {
 		// Fedora 31 is carrying a patch to display improved error
@@ -1508,6 +1514,48 @@ func (c *Container) mountNamedVolume(v *ContainerNamedVolume, mountpoint string)
 	return vol, nil
 }
 
+// Chown the specified volume if necessary.
+func (c *Container) chownVolume(volumeName string) error {
+	vol, err := c.runtime.state.Volume(volumeName)
+	if err != nil {
+		return errors.Wrapf(err, "error retrieving named volume %s for container %s", volumeName, c.ID())
+	}
+
+	uid := int(c.config.Spec.Process.User.UID)
+	gid := int(c.config.Spec.Process.User.GID)
+
+	vol.lock.Lock()
+	defer vol.lock.Unlock()
+
+	// The volume may need a copy-up. Check the state.
+	if err := vol.update(); err != nil {
+		return err
+	}
+
+	if vol.state.NeedsChown {
+		vol.state.NeedsChown = false
+		vol.state.UIDChowned = uid
+		vol.state.GIDChowned = gid
+
+		if err := vol.save(); err != nil {
+			return err
+		}
+		err := filepath.Walk(vol.MountPoint(), func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if err := os.Chown(path, uid, gid); err != nil {
+				return err
+			}
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 // cleanupStorage unmounts and cleans up the container's root filesystem
 func (c *Container) cleanupStorage() error {
 	if !c.state.Mounted {
diff --git a/libpod/options.go b/libpod/options.go
index 573806308..3120a35d7 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -1485,6 +1485,19 @@ func WithVolumeGID(gid int) VolumeCreateOption {
 	}
 }
 
+// WithVolumeNeedsChown sets the NeedsChown flag for the volume.
+func WithVolumeNeedsChown() VolumeCreateOption {
+	return func(volume *Volume) error {
+		if volume.valid {
+			return define.ErrVolumeFinalized
+		}
+
+		volume.state.NeedsChown = true
+
+		return nil
+	}
+}
+
 // withSetAnon sets a bool notifying libpod that this volume is anonymous and
 // should be removed when containers using it are removed and volumes are
 // specified for removal.
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index 4010c9bea..c073aabb5 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -309,7 +309,7 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 		logrus.Debugf("Creating new volume %s for container", vol.Name)
 
 		// The volume does not exist, so we need to create it.
-		volOptions := []VolumeCreateOption{WithVolumeName(vol.Name), WithVolumeUID(ctr.RootUID()), WithVolumeGID(ctr.RootGID())}
+		volOptions := []VolumeCreateOption{WithVolumeName(vol.Name), WithVolumeUID(ctr.RootUID()), WithVolumeGID(ctr.RootGID()), WithVolumeNeedsChown()}
 		if isAnonymous {
 			volOptions = append(volOptions, withSetAnon())
 		}
diff --git a/libpod/volume.go b/libpod/volume.go
index 72b080d1a..438957086 100644
--- a/libpod/volume.go
+++ b/libpod/volume.go
@@ -64,6 +64,14 @@ type VolumeState struct {
 	// create time, then cleared after the copy up is done and never set
 	// again.
 	NeedsCopyUp bool `json:"notYetMounted,omitempty"`
+	// NeedsChown indicates that the next time the volume is mounted into
+	// a container, the container will chown the volume to the container process
+	// UID/GID.
+	NeedsChown bool `json:"notYetChowned,omitempty"`
+	// UIDChowned is the UID the volume was chowned to.
+	UIDChowned int `json:"uidChowned,omitempty"`
+	// GIDChowned is the GID the volume was chowned to.
+	GIDChowned int `json:"gidChowned,omitempty"`
 }
 
 // Name retrieves the volume's name
@@ -113,13 +121,33 @@ func (v *Volume) Anonymous() bool {
 }
 
 // UID returns the UID the volume will be created as.
-func (v *Volume) UID() int {
-	return v.config.UID
+func (v *Volume) UID() (int, error) {
+	v.lock.Lock()
+	defer v.lock.Unlock()
+
+	if !v.valid {
+		return -1, define.ErrVolumeRemoved
+	}
+
+	if v.state.UIDChowned > 0 {
+		return v.state.UIDChowned, nil
+	}
+	return v.config.UID, nil
 }
 
 // GID returns the GID the volume will be created as.
-func (v *Volume) GID() int {
-	return v.config.GID
+func (v *Volume) GID() (int, error) {
+	v.lock.Lock()
+	defer v.lock.Unlock()
+
+	if !v.valid {
+		return -1, define.ErrVolumeRemoved
+	}
+
+	if v.state.GIDChowned > 0 {
+		return v.state.GIDChowned, nil
+	}
+	return v.config.GID, nil
 }
 
 // CreatedTime returns the time the volume was created at. It was not tracked
diff --git a/libpod/volume_inspect.go b/libpod/volume_inspect.go
index 5258792eb..85848f84f 100644
--- a/libpod/volume_inspect.go
+++ b/libpod/volume_inspect.go
@@ -65,8 +65,15 @@ func (v *Volume) Inspect() (*InspectVolumeData, error) {
 	for k, v := range v.config.Options {
 		data.Options[k] = v
 	}
-	data.UID = v.config.UID
-	data.GID = v.config.GID
+	var err error
+	data.UID, err = v.UID()
+	if err != nil {
+		return nil, err
+	}
+	data.GID, err = v.GID()
+	if err != nil {
+		return nil, err
+	}
 	data.Anonymous = v.config.IsAnon
 
 	return data, nil