podman diff accept two images or containers

First, make podman diff accept optionally a second argument. This allows
the user to specify a second image/container to compare the first with.
If it is not set the parent layer will be used as before.

Second, podman container diff should only use containers and podman
image diff should only use images. Previously, podman container diff
would use the image when both an image and container with this name
exists.

To make this work two new parameters have been added to the api. If they
are not used the previous behaviour is used. The same applies to the
bindings.

Fixes #10649

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

7 files changed, 32 insertions, 29 deletions

diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index 4cd3cfd2a..ec17d7ce3 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -23,7 +23,6 @@ type ContainerEngine interface {
 	ContainerCopyFromArchive(ctx context.Context, nameOrID string, path string, reader io.Reader) (ContainerCopyFunc, error)
 	ContainerCopyToArchive(ctx context.Context, nameOrID string, path string, writer io.Writer) (ContainerCopyFunc, 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)
 	ContainerExecDetached(ctx context.Context, nameOrID string, options ExecOptions) (string, error)
 	ContainerExists(ctx context.Context, nameOrID string, options ContainerExistsOptions) (*BoolReport, error)
@@ -52,6 +51,7 @@ type ContainerEngine interface {
 	ContainerUnmount(ctx context.Context, nameOrIDs []string, options ContainerUnmountOptions) ([]*ContainerUnmountReport, error)
 	ContainerUnpause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
 	ContainerWait(ctx context.Context, namesOrIds []string, options WaitOptions) ([]WaitReport, error)
+	Diff(ctx context.Context, namesOrIds []string, options DiffOptions) (*DiffReport, error)
 	Events(ctx context.Context, opts EventsOptions) error
 	GenerateSystemd(ctx context.Context, nameOrID string, opts GenerateSystemdOptions) (*GenerateSystemdReport, error)
 	GenerateKube(ctx context.Context, nameOrIDs []string, opts GenerateKubeOptions) (*GenerateKubeReport, error)
diff --git a/pkg/domain/entities/engine_image.go b/pkg/domain/entities/engine_image.go
index 1b2de5d5e..b0f9ae408 100644
--- a/pkg/domain/entities/engine_image.go
+++ b/pkg/domain/entities/engine_image.go
@@ -10,7 +10,6 @@ import (
 type ImageEngine interface {
 	Build(ctx context.Context, containerFiles []string, opts BuildOptions) (*BuildReport, error)
 	Config(ctx context.Context) (*config.Config, 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)
diff --git a/pkg/domain/entities/types.go b/pkg/domain/entities/types.go
index 02e374111..9e25b7bf8 100644
--- a/pkg/domain/entities/types.go
+++ b/pkg/domain/entities/types.go
@@ -4,6 +4,7 @@ import (
 	"net"
 
 	buildahDefine "github.com/containers/buildah/define"
+	"github.com/containers/podman/v3/libpod/define"
 	"github.com/containers/podman/v3/libpod/events"
 	"github.com/containers/podman/v3/pkg/specgen"
 	"github.com/containers/storage/pkg/archive"
@@ -62,9 +63,10 @@ type InspectOptions struct {
 
 // 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
+	Format  string          `json:",omitempty"` // CLI only
+	Latest  bool            `json:",omitempty"` // API and CLI, only supported by containers
+	Archive bool            `json:",omitempty"` // CLI only
+	Type    define.DiffType // Type which should be compared
 }
 
 // DiffReport provides changes for object
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index 47fa553ce..2c5300ccb 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -858,16 +858,26 @@ func (ic *ContainerEngine) ContainerListExternal(ctx context.Context) ([]entitie
 	return ps.GetExternalContainerLists(ic.Libpod)
 }
 
-// ContainerDiff provides changes to given container
-func (ic *ContainerEngine) ContainerDiff(ctx context.Context, nameOrID string, opts entities.DiffOptions) (*entities.DiffReport, error) {
+// Diff provides changes to given container
+func (ic *ContainerEngine) Diff(ctx context.Context, namesOrIDs []string, opts entities.DiffOptions) (*entities.DiffReport, error) {
+	var (
+		base   string
+		parent string
+	)
 	if opts.Latest {
 		ctnr, err := ic.Libpod.GetLatestContainer()
 		if err != nil {
 			return nil, errors.Wrap(err, "unable to get latest container")
 		}
-		nameOrID = ctnr.ID()
+		base = ctnr.ID()
+	}
+	if len(namesOrIDs) > 0 {
+		base = namesOrIDs[0]
+		if len(namesOrIDs) > 1 {
+			parent = namesOrIDs[1]
+		}
 	}
-	changes, err := ic.Libpod.GetDiff("", nameOrID)
+	changes, err := ic.Libpod.GetDiff(parent, base, opts.Type)
 	return &entities.DiffReport{Changes: changes}, err
 }
 
diff --git a/pkg/domain/infra/abi/images.go b/pkg/domain/infra/abi/images.go
index 5992181d3..6d1acb590 100644
--- a/pkg/domain/infra/abi/images.go
+++ b/pkg/domain/infra/abi/images.go
@@ -403,14 +403,6 @@ func (ir *ImageEngine) Import(ctx context.Context, options entities.ImageImportO
 	return &entities.ImageImportReport{Id: imageID}, nil
 }
 
-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
-}
-
 func (ir *ImageEngine) Search(ctx context.Context, term string, opts entities.ImageSearchOptions) ([]entities.ImageSearchReport, error) {
 	filter, err := libimage.ParseSearchFilter(opts.Filters)
 	if err != nil {
diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go
index ccebfffa4..1bee521cf 100644
--- a/pkg/domain/infra/tunnel/containers.go
+++ b/pkg/domain/infra/tunnel/containers.go
@@ -765,8 +765,18 @@ func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.Conta
 	return &report, err
 }
 
-func (ic *ContainerEngine) ContainerDiff(ctx context.Context, nameOrID string, _ entities.DiffOptions) (*entities.DiffReport, error) {
-	changes, err := containers.Diff(ic.ClientCtx, nameOrID, nil)
+func (ic *ContainerEngine) Diff(ctx context.Context, namesOrIDs []string, opts entities.DiffOptions) (*entities.DiffReport, error) {
+	var base string
+	options := new(containers.DiffOptions).WithDiffType(opts.Type.String())
+	if len(namesOrIDs) > 0 {
+		base = namesOrIDs[0]
+		if len(namesOrIDs) > 1 {
+			options.WithParent(namesOrIDs[1])
+		}
+	} else {
+		return nil, errors.New("no arguments for diff")
+	}
+	changes, err := containers.Diff(ic.ClientCtx, base, options)
 	return &entities.DiffReport{Changes: changes}, err
 }
 
diff --git a/pkg/domain/infra/tunnel/images.go b/pkg/domain/infra/tunnel/images.go
index 42027a2dc..db4e14aba 100644
--- a/pkg/domain/infra/tunnel/images.go
+++ b/pkg/domain/infra/tunnel/images.go
@@ -299,16 +299,6 @@ func (ir *ImageEngine) Save(ctx context.Context, nameOrID string, tags []string,
 	return utils2.UntarToFileSystem(opts.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) {
-	options := new(images.DiffOptions)
-	changes, err := images.Diff(ir.ClientCtx, nameOrID, options)
-	if err != nil {
-		return nil, err
-	}
-	return &entities.DiffReport{Changes: changes}, nil
-}
-
 func (ir *ImageEngine) Search(ctx context.Context, term string, opts entities.ImageSearchOptions) ([]entities.ImageSearchReport, error) {
 	mappedFilters := make(map[string][]string)
 	filters, err := libimage.ParseSearchFilter(opts.Filters)