new service: version

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

cmd/ctr/version.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	gocontext "context"
+	"fmt"
+	"os"
+
+	"github.com/containerd/containerd/version"
+	empty "github.com/golang/protobuf/ptypes/empty"
+	"github.com/urfave/cli"
+)
+
+var versionCommand = cli.Command{
+	Name:  "version",
+	Usage: "print the version",
+	Action: func(context *cli.Context) error {
+		if context.NArg() > 0 {
+			return fmt.Errorf("no argument expected")
+		}
+		fmt.Println("Client:")
+		fmt.Printf("  Version: %s\n", version.Version)
+		fmt.Printf("  Revision: %s\n", version.Revision)
+		fmt.Println("")
+		vs, err := getVersionService(context)
+		if err != nil {
+			return err
+		}
+		v, err := vs.Version(gocontext.Background(), &empty.Empty{})
+		if err != nil {
+			return err
+		}
+		fmt.Println("Server:")
+		fmt.Printf("  Version: %s\n", v.Version)
+		fmt.Printf("  Revision: %s\n", v.Revision)
+		if v.Version != version.Version {
+			fmt.Fprintf(os.Stderr, "WARNING: version mismatch\n")
+		}
+		if v.Revision != version.Revision {
+			fmt.Fprintf(os.Stderr, "WARNING: revision mismatch\n")
+		}
+		return nil
+	},
+}