rewrite podman-cp

* Add a new `pkg/copy` to centralize all container-copy related code.

* The new code is based on Buildah's `copier` package.

* The compat `/archive` endpoints use the new `copy` package.

* Update docs and an several new tests.

* Includes many fixes, most notably, the look-up of volumes and mounts.

Breaking changes:

 * Podman is now expecting that container-destination paths exist.
   Before, Podman created the paths if needed.  Docker does not do
   that and I believe Podman should not either as it's a recipe for
   masking errors.  These errors may be user induced (e.g., a path
   typo), or internal typos (e.g., when the destination may be a
   mistakenly unmounted volume).  Let's keep the magic low for such
   a security sensitive feature.

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

2 files changed, 5 insertions, 7 deletions

diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index 3fd7c79f4..39d679eaf 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -403,16 +403,14 @@ type ContainerPortReport struct {
 	Ports []ocicni.PortMapping
 }
 
-// ContainerCpOptions describes input options for cp
+// ContainerCpOptions describes input options for cp.
 type ContainerCpOptions struct {
-	Pause   bool
+	// Pause the container while copying.
+	Pause bool
+	// Extract the tarfile into the destination directory.
 	Extract bool
 }
 
-// ContainerCpReport describes the output from a cp operation
-type ContainerCpReport struct {
-}
-
 // ContainerStatsOptions describes input options for getting
 // stats on containers
 type ContainerStatsOptions struct {
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index df7da616a..e1f40e307 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -16,7 +16,7 @@ type ContainerEngine interface {
 	ContainerCheckpoint(ctx context.Context, namesOrIds []string, options CheckpointOptions) ([]*CheckpointReport, error)
 	ContainerCleanup(ctx context.Context, namesOrIds []string, options ContainerCleanupOptions) ([]*ContainerCleanupReport, error)
 	ContainerCommit(ctx context.Context, nameOrID string, options CommitOptions) (*CommitReport, error)
-	ContainerCp(ctx context.Context, source, dest string, options ContainerCpOptions) (*ContainerCpReport, error)
+	ContainerCp(ctx context.Context, source, dest string, options ContainerCpOptions) error
 	ContainerCreate(ctx context.Context, s *specgen.SpecGenerator) (*ContainerCreateReport, error)
 	ContainerDiff(ctx context.Context, nameOrID string, options DiffOptions) (*DiffReport, error)
 	ContainerExec(ctx context.Context, nameOrID string, options ExecOptions, streams define.AttachStreams) (int, error)