feat(clients/zbctl): add command to generate shell completion

clients/zbctl/cmd/completion.go

@@ -0,0 +1,51 @@
+// Copyright © 2018 Camunda Services GmbH (info@camunda.com)
+//
+// 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"
+	"github.com/zeebe-io/zeebe/clients/zbctl/utils"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var completionShellFlag string
+
+// completionCmd represents the completion command
+var completionCmd = &cobra.Command{
+	Use:   "completion",
+	Short: "Generate shell completion for zbctl",
+	Args: cobra.NoArgs,
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Println("completion called")
+		switch completionShellFlag {
+		case "bash":
+			rootCmd.GenBashCompletion(os.Stdout)
+			break
+		case "zsh":
+			rootCmd.GenZshCompletion(os.Stdout)
+			break
+		default:
+			fmt.Println("Unsupported shell for completion generation", completionShellFlag)
+			os.Exit(utils.ExitCodeConfigurationError)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(completionCmd)
+    completionCmd.Flags().StringVar(&completionShellFlag, "shell", "bash", "Shell to generate completion for")
+}