cluster/tools/kartongips: init

This forks bitnami/kubecfg into kartongips. The rationale is that we
want to implement hscloud-specific functionality that wouldn't really be
upstreamable into kubecfg (like secret support, mulit-cluster support).

We forked off from github.com/q3k/kubecfg at commit b6817a94492c561ed61a44eeea2d92dcf2e6b8c0.

Change-Id: If5ba513905e0a86f971576fe7061a471c1d8b398
diff --git a/cluster/tools/kartongips/cmd/completion.go b/cluster/tools/kartongips/cmd/completion.go
new file mode 100644
index 0000000..eb0f3ce
--- /dev/null
+++ b/cluster/tools/kartongips/cmd/completion.go
@@ -0,0 +1,75 @@
+// Copyright 2018 The kubecfg authors
+//
+//
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"unicode"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	flagShell = "shell"
+)
+
+func guessShell(path string) string {
+	ret := filepath.Base(path)
+	ret = strings.TrimRightFunc(ret, unicode.IsNumber)
+	return ret
+}
+
+func init() {
+	RootCmd.AddCommand(completionCmd)
+	completionCmd.PersistentFlags().String(flagShell, "", "Shell variant for which to generate completions.  Supported values are bash,zsh")
+}
+
+var completionCmd = &cobra.Command{
+	Use:   "completion",
+	Short: "Generate shell completions for kubecfg",
+	Args:  cobra.NoArgs,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		flags := cmd.Flags()
+
+		shell, err := flags.GetString(flagShell)
+		if err != nil {
+			return err
+		}
+		if shell == "" {
+			shell = guessShell(os.Getenv("SHELL"))
+		}
+
+		out := cmd.OutOrStdout()
+
+		switch shell {
+		case "bash":
+			if err := RootCmd.GenBashCompletion(out); err != nil {
+				return err
+			}
+		case "zsh":
+			if err := RootCmd.GenZshCompletion(out); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("Unknown shell %q, try --%s", shell, flagShell)
+		}
+
+		return nil
+	},
+}