Add support for overlay volume mounts in podman.

Add support -v for overlay volume mounts in podman.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Signed-off-by: Qi Wang <qiwan@redhat.com>

7 files changed, 78 insertions, 11 deletions

diff --git a/libpod/container.go b/libpod/container.go
index 1ca38ae7e..fda018640 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -262,6 +262,8 @@ type ContainerConfig struct {
 	Mounts []string `json:"mounts,omitempty"`
 	// NamedVolumes lists the named volumes to mount into the container.
 	NamedVolumes []*ContainerNamedVolume `json:"namedVolumes,omitempty"`
+	// OverlayVolumes lists the overlay volumes to mount into the container.
+	OverlayVolumes []*ContainerOverlayVolume `json:"overlayVolumes,omitempty"`
 
 	// Security Config
 
@@ -449,6 +451,15 @@ type ContainerNamedVolume struct {
 	Options []string `json:"options,omitempty"`
 }
 
+// ContainerOverlayVolume is a overlay volume that will be mounted into the
+// container. Each volume is a libpod Volume present in the state.
+type ContainerOverlayVolume struct {
+	// Destination is the absolute path where the mount will be placed in the container.
+	Dest string `json:"dest"`
+	// Source specifies the source path of the mount.
+	Source string `json:"source,omitempty"`
+}
+
 // Config accessors
 // Unlocked
 
diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index a79b9e5a8..b2e23b3a8 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -1588,6 +1588,12 @@ func (c *Container) cleanupStorage() error {
 		}
 	}
 
+	if err := c.cleanupOverlayMounts(); err != nil {
+		// If the container can't remove content report the error
+		logrus.Errorf("Failed to cleanup overlay mounts for %s: %v", c.ID(), err)
+		cleanupErr = err
+	}
+
 	if c.config.Rootfs != "" {
 		return cleanupErr
 	}
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index 255505416..1c21f2ff9 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -20,6 +20,7 @@ import (
 
 	cnitypes "github.com/containernetworking/cni/pkg/types/current"
 	"github.com/containernetworking/plugins/pkg/ns"
+	"github.com/containers/buildah/pkg/overlay"
 	"github.com/containers/buildah/pkg/secrets"
 	"github.com/containers/common/pkg/apparmor"
 	"github.com/containers/common/pkg/config"
@@ -319,6 +320,19 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
 		}
 	}
 
+	// Add overlay volumes
+	for _, overlayVol := range c.config.OverlayVolumes {
+		contentDir, err := overlay.TempDir(c.config.StaticDir, c.RootUID(), c.RootGID())
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to create TempDir in the %s directory", c.config.StaticDir)
+		}
+		overlayMount, err := overlay.Mount(contentDir, overlayVol.Source, overlayVol.Dest, c.RootUID(), c.RootGID(), c.runtime.store.GraphOptions())
+		if err != nil {
+			return nil, errors.Wrapf(err, "creating overlay failed %q", overlayVol.Source)
+		}
+		g.AddMount(overlayMount)
+	}
+
 	hasHomeSet := false
 	for _, s := range c.config.Spec.Process.Env {
 		if strings.HasPrefix(s, "HOME=") {
@@ -1642,3 +1656,7 @@ func (c *Container) copyTimezoneFile(zonePath string) (string, error) {
 	}
 	return localtimeCopy, err
 }
+
+func (c *Container) cleanupOverlayMounts() error {
+	return overlay.CleanupContent(c.config.StaticDir)
+}
diff --git a/libpod/container_internal_unsupported.go b/libpod/container_internal_unsupported.go
index e6d94104c..b58a5116b 100644
--- a/libpod/container_internal_unsupported.go
+++ b/libpod/container_internal_unsupported.go
@@ -46,6 +46,10 @@ func (c *Container) getOCICgroupPath() (string, error) {
 	return "", define.ErrNotImplemented
 }
 
+func (c *Container) cleanupOverlayMounts() error {
+	return nil
+}
+
 func (c *Container) getUserOverrides() *lookup.Overrides {
 	return nil
 }
diff --git a/libpod/container_validate.go b/libpod/container_validate.go
index c02833359..666ad0aca 100644
--- a/libpod/container_validate.go
+++ b/libpod/container_validate.go
@@ -99,5 +99,24 @@ 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
+	destinations := make(map[string]bool)
+	for _, vol := range c.config.NamedVolumes {
+		// 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
+	}
+	for _, vol := range c.config.OverlayVolumes {
+		// 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
 }
diff --git a/libpod/options.go b/libpod/options.go
index 32748a3c1..40cf452db 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -1380,17 +1380,7 @@ func WithNamedVolumes(volumes []*ContainerNamedVolume) CtrCreateOption {
 			return define.ErrCtrFinalized
 		}
 
-		destinations := make(map[string]bool)
-
 		for _, vol := range volumes {
-			// 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
-
 			mountOpts, err := util.ProcessOptions(vol.Options, false, "")
 			if err != nil {
 				return errors.Wrapf(err, "error processing options for named volume %q mounted at %q", vol.Name, vol.Dest)
@@ -1407,6 +1397,25 @@ func WithNamedVolumes(volumes []*ContainerNamedVolume) CtrCreateOption {
 	}
 }
 
+// WithOverlayVolumes adds the given overlay volumes to the container.
+func WithOverlayVolumes(volumes []*ContainerOverlayVolume) CtrCreateOption {
+	return func(ctr *Container) error {
+		if ctr.valid {
+			return define.ErrCtrFinalized
+		}
+
+		for _, vol := range volumes {
+
+			ctr.config.OverlayVolumes = append(ctr.config.OverlayVolumes, &ContainerOverlayVolume{
+				Dest:   vol.Dest,
+				Source: vol.Source,
+			})
+		}
+
+		return nil
+	}
+}
+
 // WithHealthCheck adds the healthcheck to the container config
 func WithHealthCheck(healthCheck *manifest.Schema2HealthConfig) CtrCreateOption {
 	return func(ctr *Container) error {
diff --git a/libpod/runtime.go b/libpod/runtime.go
index 0075c0e13..b30933b0c 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -577,7 +577,7 @@ func (r *Runtime) Shutdown(force bool) error {
 	}
 
 	var lastError error
-	// If no store was requested, it can bew nil and there is no need to
+	// If no store was requested, it can be nil and there is no need to
 	// attempt to shut it down
 	if r.store != nil {
 		if _, err := r.store.Shutdown(force); err != nil {