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>

3 files changed, 45 insertions, 2 deletions

diff --git a/pkg/api/handlers/compat/changes.go b/pkg/api/handlers/compat/changes.go
index c442abbf9..dfe656755 100644
--- a/pkg/api/handlers/compat/changes.go
+++ b/pkg/api/handlers/compat/changes.go
@@ -4,14 +4,39 @@ import (
 	"net/http"
 
 	"github.com/containers/podman/v3/libpod"
+	"github.com/containers/podman/v3/libpod/define"
 	"github.com/containers/podman/v3/pkg/api/handlers/utils"
+	"github.com/gorilla/schema"
+	"github.com/pkg/errors"
 )
 
 func Changes(w http.ResponseWriter, r *http.Request) {
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
 	runtime := r.Context().Value("runtime").(*libpod.Runtime)
 
+	query := struct {
+		Parent   string `schema:"parent"`
+		DiffType string `schema:"diffType"`
+	}{}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, "Something went wrong.", http.StatusBadRequest, errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+	var diffType define.DiffType
+	switch query.DiffType {
+	case "", "all":
+		diffType = define.DiffAll
+	case "container":
+		diffType = define.DiffContainer
+	case "image":
+		diffType = define.DiffImage
+	default:
+		utils.Error(w, "Something went wrong.", http.StatusBadRequest, errors.Errorf("invalid diffType value %q", query.DiffType))
+		return
+	}
+
 	id := utils.GetName(r)
-	changes, err := runtime.GetDiff("", id)
+	changes, err := runtime.GetDiff(query.Parent, id, diffType)
 	if err != nil {
 		utils.InternalServerError(w, err)
 		return
diff --git a/pkg/api/server/register_containers.go b/pkg/api/server/register_containers.go
index 88ebb4df5..50e059ecc 100644
--- a/pkg/api/server/register_containers.go
+++ b/pkg/api/server/register_containers.go
@@ -1505,6 +1505,15 @@ func (s *APIServer) registerContainersHandlers(r *mux.Router) error {
 	//    type: string
 	//    required: true
 	//    description: the name or id of the container
+	//  - in: query
+	//    name: parent
+	//    type: string
+	//    description: specify a second layer which is used to compare against it instead of the parent layer
+	//  - in: query
+	//    name: diffType
+	//    type: string
+	//    enum: [all, container, image]
+	//    description: select what you want to match, default is all
 	// responses:
 	//   200:
 	//     description: Array of Changes
diff --git a/pkg/api/server/register_images.go b/pkg/api/server/register_images.go
index 3410c53cd..2103c093c 100644
--- a/pkg/api/server/register_images.go
+++ b/pkg/api/server/register_images.go
@@ -1286,7 +1286,16 @@ func (s *APIServer) registerImagesHandlers(r *mux.Router) error {
 	//    name: name
 	//    type: string
 	//    required: true
-	//    description: the name or id of the container
+	//    description: the name or id of the image
+	//  - in: query
+	//    name: parent
+	//    type: string
+	//    description: specify a second layer which is used to compare against it instead of the parent layer
+	//  - in: query
+	//    name: diffType
+	//    type: string
+	//    enum: [all, container, image]
+	//    description: select what you want to match, default is all
 	// responses:
 	//   200:
 	//     description: Array of Changes