[c] Add unregister cmd

dfssc/cmd/root.go

@@ -58,6 +58,6 @@ func init() {
 	_ = viper.BindPFlag("timeout", RootCmd.PersistentFlags().Lookup("timeout"))
 
 	// Bind subcommands to root
-	RootCmd.AddCommand(dfss.VersionCmd, registerCmd, authCmd, newCmd, showCmd, fetchCmd, importCmd, exportCmd, signCmd)
+	RootCmd.AddCommand(dfss.VersionCmd, registerCmd, authCmd, newCmd, showCmd, fetchCmd, importCmd, exportCmd, signCmd, unregisterCmd)
 
 }

dfssc/cmd/unregister.go

+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"dfss/dfssc/security"
+	"dfss/dfssc/user"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var unregisterCmd = &cobra.Command{
+	Use:   "unregister",
+	Short: "delete current client information on platform",
+	Run: func(cmd *cobra.Command, args []string) {
+		// Read info from provided certificate
+		cert, err := security.GetCertificate(viper.GetString("file_cert"))
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "An error occurred:", err.Error())
+			os.Exit(2)
+		}
+
+		// Confirmation
+		var ready string
+		readStringParam("Do you REALLY want to delete "+cert.Subject.CommonName+"? Type 'yes' to confirm", "", &ready)
+		if ready != "yes" {
+			fmt.Println("Unregistering aborted!")
+			os.Exit(1)
+		}
+
+		err = user.Unregister()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "Error: cannot unregister:", err.Error())
+			os.Exit(2)
+		}
+	},
+}

dfssc/user/unregister.go

+package user
+
+import (
+	"errors"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+
+	pb "dfss/dfssp/api"
+	"dfss/net"
+)
+
+// Unregister a user from the platform
+func Unregister() error {
+	client, err := connect()
+	if err != nil {
+		return err
+	}
+
+	// Stop the context if it takes too long for the platform to answer
+	ctx, cancel := context.WithTimeout(context.Background(), net.DefaultTimeout)
+	defer cancel()
+	response, err := client.Unregister(ctx, &pb.Empty{})
+	if err != nil {
+		return errors.New(grpc.ErrorDesc(err))
+	}
+	if response.Code != pb.ErrorCode_SUCCESS {
+		return errors.New(response.Message)
+	}
+
+	return nil
+}