migration: add possibility to restore a container with a new name

The option to restore a container from an external checkpoint archive
(podman container restore -i /tmp/checkpoint.tar.gz) restores a
container with the same name and same ID as id had before checkpointing.

This commit adds the option '--name,-n' to 'podman container restore'.
With this option the restored container gets the name specified after
'--name,-n' and a new ID. This way it is possible to restore one
container multiple times.

If a container is restored with a new name Podman will not try to
request the same IP address for the container as it had during
checkpointing. This implicitly assumes that if a container is restored
from a checkpoint archive with a different name, that it will be
restored multiple times and restoring a container multiple times with
the same IP address will fail as each IP address can only be used once.

Signed-off-by: Adrian Reber <areber@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index d471d4191..4acc77afa 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -681,7 +681,13 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 	// Read network configuration from checkpoint
 	// Currently only one interface with one IP is supported.
 	networkStatusFile, err := os.Open(filepath.Join(c.bundlePath(), "network.status"))
-	if err == nil {
+	// If the restored container should get a new name, the IP address of
+	// the container will not be restored. This assumes that if a new name is
+	// specified, the container is restored multiple times.
+	// TODO: This implicit restoring with or without IP depending on an
+	//       unrelated restore parameter (--name) does not seem like the
+	//       best solution.
+	if err == nil && options.Name == "" {
 		// The file with the network.status does exist. Let's restore the
 		// container with the same IP address as during checkpointing.
 		defer networkStatusFile.Close()