Move version command into package

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

cmd/ctr/commands/version/version.go

@@ -0,0 +1,41 @@
+package version
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/containerd/containerd/cmd/ctr/commands"
+	"github.com/google/cadvisor/version"
+	"github.com/urfave/cli"
+)
+
+// Command is a cli ommand to output the client and containerd server version
+var Command = cli.Command{
+	Name:  "version",
+	Usage: "print the client and server versions",
+	Action: func(context *cli.Context) error {
+		fmt.Println("Client:")
+		fmt.Printf("  Version: %s\n", version.Version)
+		fmt.Printf("  Revision: %s\n", version.Revision)
+		fmt.Println("")
+		client, ctx, cancel, err := commands.NewClient(context)
+		if err != nil {
+			return err
+		}
+		defer cancel()
+		v, err := client.Version(ctx)
+		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
+	},
+}