fix podman container exists and diff for storage containers

Current these commands only check if a container exists in libpod. With
this fix, the commands will also check if they are in containers/storage.

This allows users to look at differences within a buildah or CRI-O container.

Currently buildah diff does not exists, so this helps out in that situation
as well as in CRI-O since the cri does not implement a diff command.

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

2 files changed, 20 insertions, 5 deletions

diff --git a/pkg/api/handlers/libpod/containers.go b/pkg/api/handlers/libpod/containers.go
index 7dde51102..8068ea1b8 100644
--- a/pkg/api/handlers/libpod/containers.go
+++ b/pkg/api/handlers/libpod/containers.go
@@ -11,6 +11,7 @@ import (
 	"github.com/containers/podman/v2/pkg/api/handlers/compat"
 	"github.com/containers/podman/v2/pkg/api/handlers/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/containers/podman/v2/pkg/domain/infra/abi"
 	"github.com/containers/podman/v2/pkg/ps"
 	"github.com/gorilla/schema"
 	"github.com/pkg/errors"
@@ -19,8 +20,12 @@ import (
 
 func ContainerExists(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	// Now use the ABI implementation to prevent us from having duplicate
+	// code.
+	containerEngine := abi.ContainerEngine{Libpod: runtime}
+
 	name := utils.GetName(r)
-	_, err := runtime.LookupContainer(name)
+	report, err := containerEngine.ContainerExists(r.Context(), name)
 	if err != nil {
 		if errors.Cause(err) == define.ErrNoSuchCtr {
 			utils.ContainerNotFound(w, name, err)
@@ -30,7 +35,11 @@ func ContainerExists(w http.ResponseWriter, r *http.Request) {
 		return
 
 	}
-	utils.WriteResponse(w, http.StatusNoContent, "")
+	if report.Value {
+		utils.WriteResponse(w, http.StatusNoContent, "")
+	} else {
+		utils.ContainerNotFound(w, name, define.ErrNoSuchCtr)
+	}
 }
 
 func ListContainers(w http.ResponseWriter, r *http.Request) {
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index 614fd5fe0..191ad8eec 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -74,11 +74,17 @@ func getContainersByContext(all, latest bool, names []string, runtime *libpod.Ru
 	return
 }
 
-// TODO: Should return *entities.ContainerExistsReport, error
+// ContainerExists returns whether the container exists in container storage
 func (ic *ContainerEngine) ContainerExists(ctx context.Context, nameOrID string) (*entities.BoolReport, error) {
 	_, err := ic.Libpod.LookupContainer(nameOrID)
-	if err != nil && errors.Cause(err) != define.ErrNoSuchCtr {
-		return nil, err
+	if err != nil {
+		if errors.Cause(err) != define.ErrNoSuchCtr {
+			return nil, err
+		}
+		// Check if container exists in storage
+		if _, storageErr := ic.Libpod.StorageContainer(nameOrID); storageErr == nil {
+			err = nil
+		}
 	}
 	return &entities.BoolReport{Value: err == nil}, nil
 }