Add experimental join command

Add `join` command to put YAML files together into one file with multiple documents.

internal/cmd/join.go

@@ -0,0 +1,91 @@
+// Copyright © 2020 The Homeport Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/gonvenience/ytbx"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v3"
+)
+
+var joinCmdSettings struct {
+	filename string
+	ending   bool
+}
+
+// joinCmd represents the get command
+var joinCmd = &cobra.Command{
+	Use:           "join <file> [<file>] [...]",
+	Aliases:       []string{"combine"},
+	Short:         "Joins multiple YAML files into a multi-document file",
+	Long:          "Joins multiple YAML files into a multi-document file.\n",
+	SilenceUsage:  true,
+	SilenceErrors: true,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		var buf bytes.Buffer
+
+		for _, location := range args {
+			location := filepath.Clean(location)
+
+			inputfile, err := ytbx.LoadFile(location)
+			if err != nil {
+				return err
+			}
+
+			for _, document := range inputfile.Documents {
+				out, err := yaml.Marshal(document)
+				if err != nil {
+					return err
+				}
+
+				fmt.Fprintf(&buf, "--- # file %s\n", location)
+				buf.Write(out)
+
+				if joinCmdSettings.ending {
+					fmt.Fprint(&buf, "...\n")
+				}
+			}
+		}
+
+		switch joinCmdSettings.filename {
+		case "-":
+			fmt.Print(buf.String())
+
+		default:
+			return ioutil.WriteFile(joinCmdSettings.filename, buf.Bytes(), os.FileMode(0644))
+		}
+
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(joinCmd)
+
+	joinCmd.PersistentFlags().StringVarP(&joinCmdSettings.filename, "name", "f", "", "Name of the target file")
+	joinCmd.PersistentFlags().BoolVarP(&joinCmdSettings.ending, "document-ending", "e", false, "Write YAML document ending ('...') after each document")
+}