add remote-client diff

the remote client now can run the diff command to report changes,
modifications, and deletions in an image or container.

Signed-off-by: baude <bbaude@redhat.com>

API.md

@@ -31,6 +31,8 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
 
 [func DeleteUnusedImages() []string](#DeleteUnusedImages)
 
+[func Diff(name: string) DiffInfo](#Diff)
+
 [func ExportContainer(name: string, path: string) string](#ExportContainer)
 
 [func ExportImage(name: string, destination: string, compress: bool, tags: []string) string](#ExportImage)
@@ -173,6 +175,8 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
 
 [type CreateResourceConfig](#CreateResourceConfig)
 
+[type DiffInfo](#DiffInfo)
+
 [type Event](#Event)
 
 [type IDMap](#IDMap)
@@ -388,6 +392,11 @@ $ varlink call -m unix:/run/podman/io.podman/io.podman.DeleteUnusedImages
   ]
 }
 ~~~
+### <a name="Diff"></a>func Diff
+<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
+
+method Diff(name: [string](https://godoc.org/builtin#string)) [DiffInfo](#DiffInfo)</div>
+
 ### <a name="ExportContainer"></a>func ExportContainer
 <div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
 
@@ -1431,6 +1440,13 @@ pids_limit [int](https://godoc.org/builtin#int)
 shm_size [int](https://godoc.org/builtin#int)
 
 ulimit [[]string](#[]string)
+### <a name="DiffInfo"></a>type DiffInfo
+
+
+
+path [string](https://godoc.org/builtin#string)
+
+changeType [string](https://godoc.org/builtin#string)
 ### <a name="Event"></a>type Event
 
 Event describes a libpod struct

cmd/podman/commands.go

@@ -14,7 +14,6 @@ func getMainCommands() []*cobra.Command {
 		_attachCommand,
 		_commitCommand,
 		_createCommand,
-		_diffCommand,
 		_execCommand,
 		_generateCommand,
 		_playCommand,
@@ -58,7 +57,6 @@ func getContainerSubCommands() []*cobra.Command {
 		_cleanupCommand,
 		_commitCommand,
 		_createCommand,
-		_diffCommand,
 		_execCommand,
 		_exportCommand,
 		_killCommand,

cmd/podman/container.go

@@ -52,6 +52,7 @@ var (
 	containerCommands = []*cobra.Command{
 		_containerExistsCommand,
 		_contInspectSubCommand,
+		_diffCommand,
 		_listSubCommand,
 		_logsCommand,
 	}

cmd/podman/diff.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"github.com/containers/buildah/pkg/formats"
 	"github.com/containers/libpod/cmd/podman/cliconfig"
-	"github.com/containers/libpod/cmd/podman/libpodruntime"
+	"github.com/containers/libpod/pkg/adapter"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -86,18 +86,17 @@ func diffCmd(c *cliconfig.DiffValues) error {
 		return errors.Errorf("container, image, or layer name must be specified: podman diff [options [...]] ID-NAME")
 	}
 
-	runtime, err := libpodruntime.GetRuntime(&c.PodmanCommand)
+	runtime, err := adapter.GetRuntime(&c.PodmanCommand)
 	if err != nil {
 		return errors.Wrapf(err, "could not get runtime")
 	}
 	defer runtime.Shutdown(false)
 
 	to := c.InputArgs[0]
-	changes, err := runtime.GetDiff("", to)
+	changes, err := runtime.Diff(c, to)
 	if err != nil {
 		return errors.Wrapf(err, "could not get changes for %q", to)
 	}
-
 	diffOutput := []diffOutputParams{}
 	outputFormat := c.Format
 

cmd/podman/main.go

@@ -36,6 +36,7 @@ var (
 // implemented.
 var mainCommands = []*cobra.Command{
 	_buildCommand,
+	_diffCommand,
 	_eventsCommand,
 	_exportCommand,
 	_historyCommand,

cmd/podman/varlink/io.podman.varlink

@@ -461,6 +461,13 @@ type Event(
     type: string
 )
 
+type DiffInfo(
+    # path that is different
+    path: string,
+    # Add, Delete, Modify
+    changeType: string
+)
+
 # GetVersion returns version and build information of the podman service
 method GetVersion() -> (
     version: string,
@@ -1154,6 +1161,8 @@ method LoadImage(name: string, inputFile: string, quiet: bool, deleteFile: bool)
 # GetEvents returns known libpod events filtered by the options provided.
 method GetEvents(filter: []string, since: string, until: string) -> (events: Event)
 
+method Diff(name: string) -> (diffs: []DiffInfo)
+
 # ImageNotFound means the image could not be found by the provided name or ID in local storage.
 error ImageNotFound (id: string, reason: string)
 

pkg/adapter/runtime.go

@@ -23,6 +23,7 @@ import (
 	"github.com/containers/libpod/libpod/events"
 	"github.com/containers/libpod/libpod/image"
 	"github.com/containers/libpod/pkg/rootless"
+	"github.com/containers/storage/pkg/archive"
 	"github.com/pkg/errors"
 )
 
@@ -430,3 +431,8 @@ func (r *LocalRuntime) Events(c *cliconfig.EventValues) error {
 	}
 	return nil
 }
+
+// Diff shows the difference in two objects
+func (r *LocalRuntime) Diff(c *cliconfig.DiffValues, to string) ([]archive.Change, error) {
+	return r.Runtime.GetDiff("", to)
+}

pkg/adapter/runtime_remote.go

@@ -831,3 +831,30 @@ func (r *LocalRuntime) Events(c *cliconfig.EventValues) error {
 	}
 	return nil
 }
+
+// Diff ...
+func (r *LocalRuntime) Diff(c *cliconfig.DiffValues, to string) ([]archive.Change, error) {
+	var changes []archive.Change
+	reply, err := iopodman.Diff().Call(r.Conn, to)
+	if err != nil {
+		return nil, err
+	}
+	for _, change := range reply {
+		changes = append(changes, archive.Change{Path: change.Path, Kind: stringToChangeType(change.ChangeType)})
+	}
+	return changes, nil
+}
+
+func stringToChangeType(change string) archive.ChangeType {
+	switch change {
+	case "A":
+		return archive.ChangeAdd
+	case "D":
+		return archive.ChangeDelete
+	default:
+		logrus.Errorf("'%s' is unknown archive type", change)
+		fallthrough
+	case "C":
+		return archive.ChangeModify
+	}
+}

pkg/varlinkapi/images.go

@@ -910,3 +910,16 @@ func (i *LibpodAPI) LoadImage(call iopodman.VarlinkCall, name, inputFile string,
 	}
 	return call.ReplyLoadImage(br)
 }
+
+// Diff ...
+func (i *LibpodAPI) Diff(call iopodman.VarlinkCall, name string) error {
+	var response []iopodman.DiffInfo
+	changes, err := i.Runtime.GetDiff("", name)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	for _, change := range changes {
+		response = append(response, iopodman.DiffInfo{Path: change.Path, ChangeType: change.Kind.String()})
+	}
+	return call.ReplyDiff(response)
+}