volumes: Add support for exporting volumes to external tar

Adds support for transferring data between systems and backing up systems.
Use cases: recover from disasters or move data between machines.

Signed-off-by: flouthoc <flouthoc.git@gmail.com>

3 files changed, 23 insertions, 0 deletions

diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index d573e4704..5d3c9480e 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -92,6 +92,7 @@ type ContainerEngine interface {
 	Version(ctx context.Context) (*SystemVersionReport, error)
 	VolumeCreate(ctx context.Context, opts VolumeCreateOptions) (*IDOrNameResponse, error)
 	VolumeExists(ctx context.Context, namesOrID string) (*BoolReport, error)
+	VolumeMounted(ctx context.Context, namesOrID string) (*BoolReport, error)
 	VolumeInspect(ctx context.Context, namesOrIds []string, opts InspectOptions) ([]*VolumeInspectReport, []error, error)
 	VolumeList(ctx context.Context, opts VolumeListOptions) ([]*VolumeListReport, error)
 	VolumePrune(ctx context.Context, options VolumePruneOptions) ([]*reports.PruneReport, error)
diff --git a/pkg/domain/infra/abi/volumes.go b/pkg/domain/infra/abi/volumes.go
index e077b10ea..1610c0b48 100644
--- a/pkg/domain/infra/abi/volumes.go
+++ b/pkg/domain/infra/abi/volumes.go
@@ -162,3 +162,19 @@ func (ic *ContainerEngine) VolumeExists(ctx context.Context, nameOrID string) (*
 	}
 	return &entities.BoolReport{Value: exists}, nil
 }
+
+// Volumemounted check if a given volume using plugin or filesystem is mounted or not.
+func (ic *ContainerEngine) VolumeMounted(ctx context.Context, nameOrID string) (*entities.BoolReport, error) {
+	vol, err := ic.Libpod.LookupVolume(nameOrID)
+	if err != nil {
+		return nil, err
+	}
+	mountCount, err := vol.MountCount()
+	if err != nil {
+		return &entities.BoolReport{Value: false}, nil
+	}
+	if mountCount > 0 {
+		return &entities.BoolReport{Value: true}, nil
+	}
+	return &entities.BoolReport{Value: false}, nil
+}
diff --git a/pkg/domain/infra/tunnel/volumes.go b/pkg/domain/infra/tunnel/volumes.go
index 2d231bad6..2b2b2c2a1 100644
--- a/pkg/domain/infra/tunnel/volumes.go
+++ b/pkg/domain/infra/tunnel/volumes.go
@@ -91,3 +91,9 @@ func (ic *ContainerEngine) VolumeExists(ctx context.Context, nameOrID string) (*
 		Value: exists,
 	}, nil
 }
+
+// Volumemounted check if a given volume using plugin or filesystem is mounted or not.
+// TODO: Not used and exposed to tunnel. Will be used by `export` command which is unavailable to `podman-remote`
+func (ic *ContainerEngine) VolumeMounted(ctx context.Context, nameOrID string) (*entities.BoolReport, error) {
+	return nil, errors.New("not implemented")
+}