LXC: Fix lxc image list --all-projects (#14833)

#14563 attempted to fix
#14561 by adding
`GetImagesAllProjects` and `GetImagesAllProjectsWithFilter` functions to
`client/simplestreams_images.go`, and moving their method signatures to
the `ImageServer` interface. Instead, we should only expand the
`InstanceServer` interface and correctly use the client functions when
`--all-projects` is set.

client/interfaces.go

@@ -50,8 +50,6 @@ type ImageServer interface {
 	GetImages() (images []api.Image, err error)
 	GetImageFingerprints() (fingerprints []string, err error)
 	GetImagesWithFilter(filters []string) (images []api.Image, err error)
-	GetImagesAllProjects() (images []api.Image, err error)
-	GetImagesAllProjectsWithFilter(filters []string) (images []api.Image, err error)
 
 	GetImage(fingerprint string) (image *api.Image, ETag string, err error)
 	GetImageFile(fingerprint string, req ImageFileRequest) (resp *ImageFileResponse, err error)
@@ -245,6 +243,8 @@ type InstanceServer interface {
 	UpdateImageAlias(name string, alias api.ImageAliasesEntryPut, ETag string) (err error)
 	RenameImageAlias(name string, alias api.ImageAliasesEntryPost) (err error)
 	DeleteImageAlias(name string) (err error)
+	GetImagesAllProjects() (images []api.Image, err error)
+	GetImagesAllProjectsWithFilter(filters []string) (images []api.Image, err error)
 
 	// Network functions ("network" API extension)
 	GetNetworkNames() (names []string, err error)

client/simplestreams_images.go

@@ -23,11 +23,6 @@ func (r *ProtocolSimpleStreams) GetImages() ([]api.Image, error) {
 	return r.ssClient.ListImages()
 }
 
-// GetImagesAllProjects returns a list of available images as Image structs.
-func (r *ProtocolSimpleStreams) GetImagesAllProjects() ([]api.Image, error) {
-	return r.GetImages()
-}
-
 // GetImageFingerprints returns a list of available image fingerprints.
 func (r *ProtocolSimpleStreams) GetImageFingerprints() ([]string, error) {
 	// Get all the images from simplestreams
@@ -50,11 +45,6 @@ func (r *ProtocolSimpleStreams) GetImagesWithFilter(filters []string) ([]api.Ima
 	return nil, fmt.Errorf("GetImagesWithFilter is not supported by the simplestreams protocol")
 }
 
-// GetImagesAllProjectsWithFilter returns an error indicating compatibility with the simplestreams protocol.
-func (r *ProtocolSimpleStreams) GetImagesAllProjectsWithFilter(filters []string) ([]api.Image, error) {
-	return nil, fmt.Errorf("GetImagesAllProjectsWithFilter is not supported by the simplestreams protocol")
-}
-
 // GetImage returns an Image struct for the provided fingerprint.
 func (r *ProtocolSimpleStreams) GetImage(fingerprint string) (*api.Image, string, error) {
 	image, err := r.ssClient.GetImage(fingerprint)

lxc/image.go

@@ -1373,9 +1373,14 @@ func (c *cmdImageList) run(cmd *cobra.Command, args []string) error {
 
 	var allImages []api.Image
 	if c.flagAllProjects {
-		allImages, err = remoteServer.GetImagesAllProjectsWithFilter(serverFilters)
+		instanceServer, ok := remoteServer.(lxd.InstanceServer)
+		if !ok {
+			return fmt.Errorf("--all-projects flag is not supported for this server")
+		}
+
+		allImages, err = instanceServer.GetImagesAllProjectsWithFilter(serverFilters)
 		if err != nil {
-			allImages, err = remoteServer.GetImagesAllProjects()
+			allImages, err = instanceServer.GetImagesAllProjects()
 			if err != nil {
 				return err
 			}