V2 podman diff(changes) support

* Ported CLI command
* Added API endpoint
* Added bindings
* Updated swagger (TODO: n endpoints, one handler)

Signed-off-by: Jhon Honce <jhonce@redhat.com>

13 files changed, 205 insertions, 13 deletions

diff --git a/pkg/api/handlers/compat/changes.go b/pkg/api/handlers/compat/changes.go
new file mode 100644
index 000000000..6907c487e
--- /dev/null
+++ b/pkg/api/handlers/compat/changes.go
@@ -0,0 +1,20 @@
+package compat
+
+import (
+	"net/http"
+
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/pkg/api/handlers/utils"
+)
+
+func Changes(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+
+	id := utils.GetName(r)
+	changes, err := runtime.GetDiff("", id)
+	if err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+	utils.WriteJSON(w, 200, changes)
+}
diff --git a/pkg/api/handlers/compat/swagger.go b/pkg/api/handlers/compat/swagger.go
index cbd8e61fb..f1aabf987 100644
--- a/pkg/api/handlers/compat/swagger.go
+++ b/pkg/api/handlers/compat/swagger.go
@@ -2,6 +2,7 @@ package compat
 
 import (
 	"github.com/containers/libpod/pkg/api/handlers/utils"
+	"github.com/containers/storage/pkg/archive"
 )
 
 // Create container
@@ -25,3 +26,12 @@ type swagCtrWaitResponse struct {
 		}
 	}
 }
+
+// Object Changes
+// swagger:response Changes
+type swagChangesResponse struct {
+	// in:body
+	Body struct {
+		Changes []archive.Change
+	}
+}
diff --git a/pkg/api/server/register_containers.go b/pkg/api/server/register_containers.go
index f126112d0..150cca872 100644
--- a/pkg/api/server/register_containers.go
+++ b/pkg/api/server/register_containers.go
@@ -1377,5 +1377,40 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: "#/responses/InternalError"
 	r.HandleFunc(VersionedPath("/libpod/containers/{name}/restore"), s.APIHandler(libpod.Restore)).Methods(http.MethodPost)
+
+	// swagger:operation GET /containers/{name}/changes libpod libpodChangesContainer
+	// swagger:operation GET /libpod/containers/{name}/changes compat changesContainer
+	// ---
+	// tags:
+	//   - containers
+	//   - containers (compat)
+	// summary: Report on changes to container's filesystem; adds, deletes or modifications.
+	// description: |
+	//   Returns which files in a container's filesystem have been added, deleted, or modified. The Kind of modification can be one of:
+	//
+	//   0: Modified
+	//   1: Added
+	//   2: Deleted
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or id of the container
+	// responses:
+	//   200:
+	//     description: Array of Changes
+	//     content:
+	//       application/json:
+	//       schema:
+	//         $ref: "#/responses/Changes"
+	//   404:
+	//     $ref: "#/responses/NoSuchContainer"
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/containers/{name}/changes"), s.APIHandler(compat.Changes))
+	r.HandleFunc("/containers/{name}/changes", s.APIHandler(compat.Changes))
+	r.HandleFunc(VersionedPath("/libpod/containers/{name}/changes"), s.APIHandler(compat.Changes))
+
 	return nil
 }
diff --git a/pkg/api/server/register_images.go b/pkg/api/server/register_images.go
index d45423096..77560e789 100644
--- a/pkg/api/server/register_images.go
+++ b/pkg/api/server/register_images.go
@@ -1125,5 +1125,36 @@ func (s *APIServer) registerImagesHandlers(r *mux.Router) error {
 	//   500:
 	//     $ref: '#/responses/InternalError'
 	r.Handle(VersionedPath("/libpod/images/{name:.*}/untag"), s.APIHandler(libpod.UntagImage)).Methods(http.MethodPost)
+
+	// swagger:operation GET /libpod/images/{name}/changes libpod libpodChangesImages
+	// ---
+	// tags:
+	//   - images
+	// summary: Report on changes to images's filesystem; adds, deletes or modifications.
+	// description: |
+	//   Returns which files in a images's filesystem have been added, deleted, or modified. The Kind of modification can be one of:
+	//
+	//   0: Modified
+	//   1: Added
+	//   2: Deleted
+	// parameters:
+	//  - in: path
+	//    name: name
+	//    type: string
+	//    required: true
+	//    description: the name or id of the container
+	// responses:
+	//   200:
+	//     description: Array of Changes
+	//     content:
+	//       application/json:
+	//       schema:
+	//         $ref: "#/responses/Changes"
+	//   404:
+	//     $ref: "#/responses/NoSuchContainer"
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/images/{name}/changes"), s.APIHandler(compat.Changes))
+
 	return nil
 }
diff --git a/pkg/bindings/containers/diff.go b/pkg/bindings/containers/diff.go
new file mode 100644
index 000000000..82070ca9a
--- /dev/null
+++ b/pkg/bindings/containers/diff.go
@@ -0,0 +1,24 @@
+package containers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/containers/libpod/pkg/bindings"
+	"github.com/containers/storage/pkg/archive"
+)
+
+// Diff provides the changes between two container layers
+func Diff(ctx context.Context, nameOrId string) ([]archive.Change, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	response, err := conn.DoRequest(nil, http.MethodGet, "/containers/%s/changes", nil, nameOrId)
+	if err != nil {
+		return nil, err
+	}
+	var changes []archive.Change
+	return changes, response.Process(&changes)
+}
diff --git a/pkg/bindings/images/diff.go b/pkg/bindings/images/diff.go
new file mode 100644
index 000000000..cfdd06a97
--- /dev/null
+++ b/pkg/bindings/images/diff.go
@@ -0,0 +1,24 @@
+package images
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/containers/libpod/pkg/bindings"
+	"github.com/containers/storage/pkg/archive"
+)
+
+// Diff provides the changes between two container layers
+func Diff(ctx context.Context, nameOrId string) ([]archive.Change, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	response, err := conn.DoRequest(nil, http.MethodGet, "/images/%s/changes", nil, nameOrId)
+	if err != nil {
+		return nil, err
+	}
+	var changes []archive.Change
+	return changes, response.Process(&changes)
+}
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index 576ce1658..e7fa67209 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -9,18 +9,19 @@ import (
 
 type ContainerEngine interface {
 	ContainerAttach(ctx context.Context, nameOrId string, options AttachOptions) error
-	ContainerCommit(ctx context.Context, nameOrId string, options CommitOptions) (*CommitReport, error)
 	ContainerCheckpoint(ctx context.Context, namesOrIds []string, options CheckpointOptions) ([]*CheckpointReport, error)
-	ContainerRestore(ctx context.Context, namesOrIds []string, options RestoreOptions) ([]*RestoreReport, error)
+	ContainerCommit(ctx context.Context, nameOrId string, options CommitOptions) (*CommitReport, 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) (int, error)
 	ContainerExists(ctx context.Context, nameOrId string) (*BoolReport, error)
-	ContainerInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]*ContainerInspectReport, error)
 	ContainerExport(ctx context.Context, nameOrId string, options ContainerExportOptions) error
+	ContainerInspect(ctx context.Context, namesOrIds []string, options InspectOptions) ([]*ContainerInspectReport, error)
 	ContainerKill(ctx context.Context, namesOrIds []string, options KillOptions) ([]*KillReport, error)
-	ContainerPause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
 	ContainerList(ctx context.Context, options ContainerListOptions) ([]ListContainer, error)
+	ContainerPause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
 	ContainerRestart(ctx context.Context, namesOrIds []string, options RestartOptions) ([]*RestartReport, error)
+	ContainerRestore(ctx context.Context, namesOrIds []string, options RestoreOptions) ([]*RestoreReport, error)
 	ContainerRm(ctx context.Context, namesOrIds []string, options RmOptions) ([]*RmReport, error)
 	ContainerStart(ctx context.Context, namesOrIds []string, options ContainerStartOptions) ([]*ContainerStartReport, error)
 	ContainerRun(ctx context.Context, opts ContainerRunOptions) (*ContainerRunReport, error)
@@ -29,9 +30,9 @@ type ContainerEngine interface {
 	ContainerUnpause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
 	ContainerWait(ctx context.Context, namesOrIds []string, options WaitOptions) ([]WaitReport, error)
 	HealthCheckRun(ctx context.Context, nameOrId string, options HealthCheckOptions) (*define.HealthCheckResults, error)
-
 	PodCreate(ctx context.Context, opts PodCreateOptions) (*PodCreateReport, error)
 	PodExists(ctx context.Context, nameOrId string) (*BoolReport, error)
+	PodInspect(ctx context.Context, options PodInspectOptions) (*PodInspectReport, error)
 	PodKill(ctx context.Context, namesOrIds []string, options PodKillOptions) ([]*PodKillReport, error)
 	PodPause(ctx context.Context, namesOrIds []string, options PodPauseOptions) ([]*PodPauseReport, error)
 	PodPs(ctx context.Context, options PodPSOptions) ([]*ListPodsReport, error)
@@ -41,8 +42,6 @@ type ContainerEngine interface {
 	PodStop(ctx context.Context, namesOrIds []string, options PodStopOptions) ([]*PodStopReport, error)
 	PodTop(ctx context.Context, options PodTopOptions) (*StringSliceReport, error)
 	PodUnpause(ctx context.Context, namesOrIds []string, options PodunpauseOptions) ([]*PodUnpauseReport, error)
-	PodInspect(ctx context.Context, options PodInspectOptions) (*PodInspectReport, error)
-
 	VolumeCreate(ctx context.Context, opts VolumeCreateOptions) (*IdOrNameResponse, error)
 	VolumeInspect(ctx context.Context, namesOrIds []string, opts VolumeInspectOptions) ([]*VolumeInspectReport, error)
 	VolumeList(ctx context.Context, opts VolumeListOptions) ([]*VolumeListReport, error)
diff --git a/pkg/domain/entities/engine_image.go b/pkg/domain/entities/engine_image.go
index a28bfc548..16b96e9ef 100644
--- a/pkg/domain/entities/engine_image.go
+++ b/pkg/domain/entities/engine_image.go
@@ -6,16 +6,17 @@ import (
 
 type ImageEngine interface {
 	Delete(ctx context.Context, nameOrId []string, opts ImageDeleteOptions) (*ImageDeleteReport, error)
+	Diff(ctx context.Context, nameOrId string, options DiffOptions) (*DiffReport, error)
 	Exists(ctx context.Context, nameOrId string) (*BoolReport, error)
 	History(ctx context.Context, nameOrId string, opts ImageHistoryOptions) (*ImageHistoryReport, error)
+	Import(ctx context.Context, opts ImageImportOptions) (*ImageImportReport, error)
 	Inspect(ctx context.Context, names []string, opts InspectOptions) (*ImageInspectReport, error)
 	List(ctx context.Context, opts ImageListOptions) ([]*ImageSummary, error)
+	Load(ctx context.Context, opts ImageLoadOptions) (*ImageLoadReport, error)
 	Prune(ctx context.Context, opts ImagePruneOptions) (*ImagePruneReport, error)
 	Pull(ctx context.Context, rawImage string, opts ImagePullOptions) (*ImagePullReport, error)
-	Tag(ctx context.Context, nameOrId string, tags []string, options ImageTagOptions) error
-	Untag(ctx context.Context, nameOrId string, tags []string, options ImageUntagOptions) error
-	Load(ctx context.Context, opts ImageLoadOptions) (*ImageLoadReport, error)
-	Import(ctx context.Context, opts ImageImportOptions) (*ImageImportReport, error)
 	Push(ctx context.Context, source string, destination string, opts ImagePushOptions) error
 	Save(ctx context.Context, nameOrId string, tags []string, options ImageSaveOptions) error
+	Tag(ctx context.Context, nameOrId string, tags []string, options ImageTagOptions) error
+	Untag(ctx context.Context, nameOrId string, tags []string, options ImageUntagOptions) error
 }
diff --git a/pkg/domain/entities/types.go b/pkg/domain/entities/types.go
index dd7aaa07f..7e35957f4 100644
--- a/pkg/domain/entities/types.go
+++ b/pkg/domain/entities/types.go
@@ -4,6 +4,7 @@ import (
 	"net"
 
 	"github.com/containers/libpod/pkg/specgen"
+	"github.com/containers/storage/pkg/archive"
 	"github.com/cri-o/ocicni/pkg/ocicni"
 )
 
@@ -49,3 +50,15 @@ type InspectOptions struct {
 	Latest bool   `json:",omitempty"`
 	Size   bool   `json:",omitempty"`
 }
+
+// All API and CLI diff commands and diff sub-commands use the same options
+type DiffOptions struct {
+	Format  string `json:",omitempty"` // CLI only
+	Latest  bool   `json:",omitempty"` // API and CLI, only supported by containers
+	Archive bool   `json:",omitempty"` // CLI only
+}
+
+// DiffReport provides changes for object
+type DiffReport struct {
+	Changes []archive.Change
+}
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index 828ee56f0..ccbe6d4fd 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -599,9 +599,9 @@ func (ic *ContainerEngine) ContainerStart(ctx context.Context, namesOrIds []stri
 				ExitCode: 125,
 			}
 			if err := ctr.Start(ctx, ctr.PodID() != ""); err != nil {
-				//if lastError != nil {
+				// if lastError != nil {
 				//	fmt.Fprintln(os.Stderr, lastError)
-				//}
+				// }
 				report.Err = err
 				if errors.Cause(err) == define.ErrWillDeadlock {
 					report.Err = errors.Wrapf(err, "please run 'podman system renumber' to resolve deadlocks")
@@ -623,6 +623,19 @@ func (ic *ContainerEngine) ContainerList(ctx context.Context, options entities.C
 	return ps.GetContainerLists(ic.Libpod, options)
 }
 
+// ContainerDiff provides changes to given container
+func (ic *ContainerEngine) ContainerDiff(ctx context.Context, nameOrId string, opts entities.DiffOptions) (*entities.DiffReport, error) {
+	if opts.Latest {
+		ctnr, err := ic.Libpod.GetLatestContainer()
+		if err != nil {
+			return nil, errors.Wrap(err, "unable to get latest container")
+		}
+		nameOrId = ctnr.ID()
+	}
+	changes, err := ic.Libpod.GetDiff("", nameOrId)
+	return &entities.DiffReport{Changes: changes}, err
+}
+
 func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.ContainerRunOptions) (*entities.ContainerRunReport, error) {
 	var (
 		joinPod bool
diff --git a/pkg/domain/infra/abi/images.go b/pkg/domain/infra/abi/images.go
index 9d706a112..2edef2723 100644
--- a/pkg/domain/infra/abi/images.go
+++ b/pkg/domain/infra/abi/images.go
@@ -413,3 +413,11 @@ func (ir *ImageEngine) Save(ctx context.Context, nameOrId string, tags []string,
 	}
 	return newImage.Save(ctx, nameOrId, options.Format, options.Output, tags, options.Quiet, options.Compress)
 }
+
+func (ir *ImageEngine) Diff(_ context.Context, nameOrId string, _ entities.DiffOptions) (*entities.DiffReport, error) {
+	changes, err := ir.Libpod.GetDiff("", nameOrId)
+	if err != nil {
+		return nil, err
+	}
+	return &entities.DiffReport{Changes: changes}, nil
+}
diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go
index e96200c5b..b22c6e3ba 100644
--- a/pkg/domain/infra/tunnel/containers.go
+++ b/pkg/domain/infra/tunnel/containers.go
@@ -324,3 +324,8 @@ func (ic *ContainerEngine) ContainerList(ctx context.Context, options entities.C
 func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.ContainerRunOptions) (*entities.ContainerRunReport, error) {
 	return nil, errors.New("not implemented")
 }
+
+func (ic *ContainerEngine) ContainerDiff(ctx context.Context, nameOrId string, _ entities.DiffOptions) (*entities.DiffReport, error) {
+	changes, err := containers.Diff(ic.ClientCxt, nameOrId)
+	return &entities.DiffReport{Changes: changes}, err
+}
diff --git a/pkg/domain/infra/tunnel/images.go b/pkg/domain/infra/tunnel/images.go
index 516914a68..66abd7f47 100644
--- a/pkg/domain/infra/tunnel/images.go
+++ b/pkg/domain/infra/tunnel/images.go
@@ -241,3 +241,12 @@ func (ir *ImageEngine) Save(ctx context.Context, nameOrId string, tags []string,
 	}
 	return utils2.UntarToFileSystem(options.Output, f, nil)
 }
+
+// Diff reports the changes to the given image
+func (ir *ImageEngine) Diff(ctx context.Context, nameOrId string, _ entities.DiffOptions) (*entities.DiffReport, error) {
+	changes, err := images.Diff(ir.ClientCxt, nameOrId)
+	if err != nil {
+		return nil, err
+	}
+	return &entities.DiffReport{Changes: changes}, nil
+}