Add support for external container

External containers are containers created outside of Podman.
For example Buildah and CRI-O Containers.

$ buildah from alpine
alpine-working-container
$ buildah run alpine-working-container touch /test
$ podman container exists --external alpine-working-container

$ podman container diff alpine-working-container
C /etc
A /test

Added --external flag to refer to external containers, rather then --storage.

Added --external for podman container exists and modified podman ps to use
--external rather then --storage.  It was felt that --storage would confuse
the user into thinking about changing the storage driver or options.

--storage is still supported through the use of aliases.

Finally podman contianer diff, does not require the --external flag, since it
there is little change of users making the mistake, and would just be a pain
for the user to remember the flag.

podman container exists --external is required because it could fool scripts
that rely on the existance of a Podman container, and there is a potential
for a partial deletion of a container, which could mess up existing users.

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

2 files changed, 6 insertions, 1 deletions

diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index 3b6dd106f..46b169284 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -246,6 +246,11 @@ type ExecOptions struct {
 	WorkDir     string
 }
 
+// ContainerExistsOptions describes the cli values to check if a container exists
+type ContainerExistsOptions struct {
+	External bool
+}
+
 // ContainerStartOptions describes the val from the
 // CLI needed to start a container
 type ContainerStartOptions struct {
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index 803a59932..a20d3b404 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -21,7 +21,7 @@ type ContainerEngine interface {
 	ContainerDiff(ctx context.Context, nameOrID string, options DiffOptions) (*DiffReport, error)
 	ContainerExec(ctx context.Context, nameOrID string, options ExecOptions, streams define.AttachStreams) (int, error)
 	ContainerExecDetached(ctx context.Context, nameOrID string, options ExecOptions) (string, error)
-	ContainerExists(ctx context.Context, nameOrID string) (*BoolReport, error)
+	ContainerExists(ctx context.Context, nameOrID string, options ContainerExistsOptions) (*BoolReport, error)
 	ContainerExport(ctx context.Context, nameOrID string, options ContainerExportOptions) error
 	ContainerInit(ctx context.Context, namesOrIds []string, options ContainerInitOptions) ([]*ContainerInitReport, error)
 	ContainerInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]*ContainerInspectReport, []error, error)