Add Server.Version and cmd/client test code

Signed-off-by: Haiyan Meng <hmeng@redhat.com>

server/exec.go

@@ -0,0 +1,31 @@
+package server
+
+import (
+	"bytes"
+	"os/exec"
+	"strings"
+)
+
+func execCmd(name string, args ...string) (string, error) {
+	cmd := exec.Command(name, args...)
+	var out bytes.Buffer
+	cmd.Stdout = &out
+
+	err := cmd.Run()
+	if err != nil {
+		return "", err
+	}
+
+	return out.String(), nil
+}
+
+func execRuncVersion(name string, args ...string) (string, error) {
+	out, err := execCmd(name, args...)
+	if err != nil {
+		return "", err
+	}
+
+	firstLine := out[:strings.Index(out, "\n")]
+	v := firstLine[strings.LastIndex(firstLine, " ")+1:]
+	return v, nil
+}

server/server.go

@@ -1,6 +1,9 @@
 package server
 
 import (
+	"errors"
+	"strings"
+
 	pb "github.com/kubernetes/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
 	"golang.org/x/net/context"
 )
@@ -9,8 +12,36 @@ import (
 type Server struct{}
 
 // Version returns the runtime name, runtime version and runtime API version
-func (s *Server) Version(context.Context, *pb.VersionRequest) (*pb.VersionResponse, error) {
-	return nil, nil
+func (s *Server) Version(ctx context.Context, req *pb.VersionRequest) (*pb.VersionResponse, error) {
+	var err error
+
+	version, err := getGPRCVersion()
+	if err != nil {
+		return nil, nil
+	}
+
+	// FIXME: the logic here may need to be changed. How to determine whether the client/server APIs are compatible?
+	if strings.Compare(version, *req.Version) != 0 {
+		return &pb.VersionResponse{
+			Version: &version,
+		}, errors.New("The version of the gRPC server API is different from the version of the gRPC client API.")
+	}
+
+	runtimeName := "runc"
+
+	runtimeVersion, err := execRuncVersion("runc", "-v")
+	if err != nil {
+		return nil, nil
+	}
+
+	runtimeApiVersion := "v1alpha1"
+
+	return &pb.VersionResponse{
+		Version:           &version,
+		RuntimeName:       &runtimeName,
+		RuntimeVersion:    &runtimeVersion,
+		RuntimeApiVersion: &runtimeApiVersion,
+	}, nil
 }
 
 // CreatePodSandbox creates a pod-level sandbox.

server/utils.go

@@ -0,0 +1,27 @@
+package server
+
+import (
+	"errors"
+	"fmt"
+	"path/filepath"
+	"runtime"
+)
+
+func getGPRCVersion() (string, error) {
+	_, file, _, ok := runtime.Caller(0)
+	if !ok {
+		return "", errors.New("Failed to recover the caller information.")
+	}
+
+	ocidRoot := filepath.Dir(filepath.Dir(file))
+	p := filepath.Join(ocidRoot, "Godeps/Godeps.json")
+
+	grepCmd := fmt.Sprintf(`grep -r "\"google.golang.org/grpc\"" %s -A 1 | grep "\"Rev\"" | cut -d: -f2 | tr -d ' "\n'`, p)
+
+	out, err := execCmd("bash", "-c", grepCmd)
+	if err != nil {
+		return "", err
+	}
+
+	return out, err
+}