*: abstractions and ImageService

plus some fix here and there

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

server/server.go

@@ -1,113 +1,52 @@
 package server
 
-import (
-	"path/filepath"
-
-	pb "github.com/kubernetes/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
-	"github.com/opencontainers/ocitools/generate"
-	"golang.org/x/net/context"
+const (
+	runtimeAPIVersion = "v1alpha1"
 )
 
-// Server implements the RuntimeService
-type Server struct{}
+// Server implements the RuntimeService and ImageService
+type Server struct {
+	runtime ociRuntime
+}
 
-// Version returns the runtime name, runtime version and runtime API version
-func (s *Server) Version(ctx context.Context, req *pb.VersionRequest) (*pb.VersionResponse, error) {
-	var err error
-
-	version, err := getGPRCVersion()
-	if err != nil {
-		return nil, err
-	}
-
-	runtimeName := "runc"
-
-	runtimeVersion, err := execRuncVersion("runc", "-v")
-	if err != nil {
-		return nil, err
-	}
-
-	runtimeApiVersion := "v1alpha1"
-
-	return &pb.VersionResponse{
-		Version:           &version,
-		RuntimeName:       &runtimeName,
-		RuntimeVersion:    &runtimeVersion,
-		RuntimeApiVersion: &runtimeApiVersion,
+// New creates a new Server with options provided
+func New(runtimePath string) (*Server, error) {
+	// TODO(runcom): runtimePath arg is unused but it might be useful
+	// if we're willing to open the doors to other runtimes in the future.
+	r := &runcRuntime{}
+	return &Server{
+		runtime: r,
 	}, nil
 }
 
-// CreatePodSandbox creates a pod-level sandbox.
-// The definition of PodSandbox is at https://github.com/kubernetes/kubernetes/pull/25899
-func (s *Server) CreatePodSandbox(ctx context.Context, req *pb.CreatePodSandboxRequest) (*pb.CreatePodSandboxResponse, error) {
-	var err error
-
-	// TODO: Parametrize as a global argument to ocid
-	ocidSandboxDir := "/var/lib/ocid/sandbox"
-	podSandboxDir := filepath.Join(ocidSandboxDir, req.GetConfig().GetName())
-
-	g := generate.New()
-
-	// TODO: Customize the config per the settings in the req
-	err = g.SaveToFile(filepath.Join(podSandboxDir, "config.json"))
-
-	return nil, err
+// TODO(runcom): export? this is being done just because runc shows a 3 line version :/
+// but it might actually be a useful abstraction (?)
+type ociRuntime interface {
+	Name() string
+	Path() (string, error)
+	Version() (string, error)
 }
 
-// StopPodSandbox stops the sandbox. If there are any running containers in the
-// sandbox, they should be force terminated.
-func (s *Server) StopPodSandbox(context.Context, *pb.StopPodSandboxRequest) (*pb.StopPodSandboxResponse, error) {
-	return nil, nil
+type runcRuntime struct {
 }
 
-// DeletePodSandbox deletes the sandbox. If there are any running containers in the
-// sandbox, they should be force deleted.
-func (s *Server) DeletePodSandbox(context.Context, *pb.DeletePodSandboxRequest) (*pb.DeletePodSandboxResponse, error) {
-	return nil, nil
+func (r *runcRuntime) Name() string {
+	return "runc"
 }
 
-// PodSandboxStatus returns the Status of the PodSandbox.
-func (s *Server) PodSandboxStatus(context.Context, *pb.PodSandboxStatusRequest) (*pb.PodSandboxStatusResponse, error) {
-	return nil, nil
+func (r *runcRuntime) Path() (string, error) {
+	// TODO(runcom): we're saying runc is always in $PATH here for now
+	return "runc", nil
 }
 
-// ListPodSandbox returns a list of SandBox.
-func (s *Server) ListPodSandbox(context.Context, *pb.ListPodSandboxRequest) (*pb.ListPodSandboxResponse, error) {
-	return nil, nil
-}
-
-// CreateContainer creates a new container in specified PodSandbox
-func (s *Server) CreateContainer(context.Context, *pb.CreateContainerRequest) (*pb.CreateContainerResponse, error) {
-	return nil, nil
-}
-
-// StartContainer starts the container.
-func (s *Server) StartContainer(context.Context, *pb.StartContainerRequest) (*pb.StartContainerResponse, error) {
-	return nil, nil
-}
-
-// StopContainer stops a running container with a grace period (i.e., timeout).
-func (s *Server) StopContainer(context.Context, *pb.StopContainerRequest) (*pb.StopContainerResponse, error) {
-	return nil, nil
-}
-
-// RemoveContainer removes the container. If the container is running, the container
-// should be force removed.
-func (s *Server) RemoveContainer(context.Context, *pb.RemoveContainerRequest) (*pb.RemoveContainerResponse, error) {
-	return nil, nil
-}
-
-// ListContainers lists all containers by filters.
-func (s *Server) ListContainers(context.Context, *pb.ListContainersRequest) (*pb.ListContainersResponse, error) {
-	return nil, nil
-}
-
-// ContainerStatus returns status of the container.
-func (s *Server) ContainerStatus(context.Context, *pb.ContainerStatusRequest) (*pb.ContainerStatusResponse, error) {
-	return nil, nil
-}
-
-// Exec executes the command in the container.
-func (s *Server) Exec(pb.RuntimeService_ExecServer) error {
-	return nil
+func (r *runcRuntime) Version() (string, error) {
+	path, err := r.Path()
+	if err != nil {
+		return "", err
+	}
+	runtimeVersion, err := execRuncVersion(path, "-v")
+	if err != nil {
+		return "", err
+	}
+	return runtimeVersion, nil
 }