feat(flux get): add --output flag, yaml only

cmd/flux/get.go

@@ -68,6 +68,7 @@ type GetFlags struct {
 	statusSelector string
 	labelSelector  string
 	watch          bool
+	outputFormat   string
 }
 
 var getArgs GetFlags
@@ -81,6 +82,7 @@ func init() {
 		"specify the status condition name and the desired state to filter the get result, e.g. ready=false")
 	getCmd.PersistentFlags().StringVarP(&getArgs.labelSelector, "label-selector", "l", "",
 		"filter objects by label selector")
+	getCmd.PersistentFlags().StringVarP(&getArgs.outputFormat, "output", "o", "table", "Output format. One of: (table, yaml), default: table")
 	rootCmd.AddCommand(getCmd)
 }
 
@@ -168,6 +170,26 @@ func (get getCommand) run(cmd *cobra.Command, args []string) error {
 		})
 	}
 
+	outputFormat := getArgs.outputFormat
+
+	switch outputFormat {
+	case "yaml":
+	case "table":
+	case "":
+		outputFormat = "table"
+	default:
+		return fmt.Errorf("unknown output format: '%s'", outputFormat)
+	}
+
+	if outputFormat != "table" {
+		if getArgs.noHeader {
+			return fmt.Errorf("cannot set no-header in %s output", outputFormat)
+		}
+		if getArgs.watch {
+			return fmt.Errorf("cannot set watch mode in %s output", outputFormat)
+		}
+	}
+
 	getAll := cmd.Use == "all"
 
 	if getArgs.watch {
@@ -198,25 +220,31 @@ func (get getCommand) run(cmd *cobra.Command, args []string) error {
 		return nil
 	}
 
+	displayNamespaces := getArgs.allNamespaces || outputFormat != "table"
+
 	var header []string
 	if !getArgs.noHeader {
-		header = get.list.headers(getArgs.allNamespaces)
+		header = get.list.headers(displayNamespaces)
 	}
 
-	rows, err := getRowsToPrint(getAll, get.list)
+	rows, err := getRowsToPrint(getAll, displayNamespaces, get.list)
 	if err != nil {
 		return err
 	}
 
-	err = printers.TablePrinter(header).Print(cmd.OutOrStdout(), rows)
+	switch outputFormat {
+	case "yaml":
+		err = printers.YamlPrinter(header).Print(cmd.OutOrStdout(), rows)
+	case "table":
+		err = printers.TablePrinter(header).Print(cmd.OutOrStdout(), rows)
+		if getAll && err != nil {
+			fmt.Println()
+		}
+	}
 	if err != nil {
 		return err
 	}
 
-	if getAll {
-		fmt.Println()
-	}
-
 	return nil
 }
 
@@ -227,7 +255,7 @@ func namespaceNameOrAny(allNamespaces bool, namespaceName string) string {
 	return fmt.Sprintf("%q", namespaceName)
 }
 
-func getRowsToPrint(getAll bool, list summarisable) ([][]string, error) {
+func getRowsToPrint(getAll bool, displayNamespace bool, list summarisable) ([][]string, error) {
 	noFilter := true
 	var conditionType, conditionStatus string
 	if getArgs.statusSelector != "" {
@@ -242,7 +270,7 @@ func getRowsToPrint(getAll bool, list summarisable) ([][]string, error) {
 	var rows [][]string
 	for i := 0; i < list.len(); i++ {
 		if noFilter || list.statusSelectorMatches(i, conditionType, conditionStatus) {
-			row := list.summariseItem(i, getArgs.allNamespaces, getAll)
+			row := list.summariseItem(i, displayNamespace, getAll)
 			rows = append(rows, row)
 		}
 	}
@@ -277,7 +305,7 @@ func watchUntil(ctx context.Context, w watch.Interface, get *getCommand) (bool,
 		if !getArgs.noHeader {
 			header = sink.headers(getArgs.allNamespaces)
 		}
-		rows, err := getRowsToPrint(false, sink)
+		rows, err := getRowsToPrint(false, getArgs.allNamespaces, sink)
 		if err != nil {
 			return false, err
 		}

cmd/flux/get_test.go

@@ -49,6 +49,11 @@ func Test_GetCmd(t *testing.T) {
 			args:     `-l "sharding.fluxcd.io/key notin (shard1, shard2)"`,
 			expected: "testdata/get/get_label_two.golden",
 		},
+		{
+			name:     "yaml output",
+			args:     `--output yaml`,
+			expected: "testdata/get/get_yaml.golden",
+		},
 	}
 
 	for _, tt := range tests {

cmd/flux/testdata/get/get_yaml.golden

@@ -0,0 +1,18 @@
+- Message: 'Fetched revision: main@sha1:696f056d'
+  Name: podinfo
+  Namespace: flux-system-15
+  Ready: true
+  Revision: main@sha1:696f056d
+  Suspended: false
+- Message: 'Fetched revision: main@sha1:696f056d'
+  Name: podinfo-shard1
+  Namespace: flux-system-15
+  Ready: true
+  Revision: main@sha1:696f056d
+  Suspended: false
+- Message: 'Fetched revision: main@sha1:696f056d'
+  Name: podinfo-shard2
+  Namespace: flux-system-15
+  Ready: true
+  Revision: main@sha1:696f056d
+  Suspended: false

pkg/printers/yaml_printer.go

@@ -0,0 +1,70 @@
+/*
+Copyright 2022 The Flux 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 printers
+
+import (
+	"fmt"
+	"io"
+
+	"sigs.k8s.io/yaml"
+)
+
+// YamlPrinter is a printer that prints Flux cmd outputs as yaml.
+func YamlPrinter(header []string) PrinterFunc {
+	return func(w io.Writer, args ...interface{}) error {
+		// args is 2d array of string
+		// headers is 1d array of string
+		var rows [][]string
+		for _, arg := range args {
+			switch arg := arg.(type) {
+			case []interface{}:
+				for _, v := range arg {
+					s, ok := v.([][]string)
+					if !ok {
+						return fmt.Errorf("unsupported type %T", v)
+					}
+					rows = append(rows, s...)
+				}
+			default:
+				return fmt.Errorf("unsupported type %T", arg)
+			}
+		}
+
+		var entries []map[string]interface{}
+		for _, row := range rows {
+			entry := make(map[string]interface{})
+			for j, h := range header {
+				if row[j] == "True" || row[j] == "False" {
+					entry[h] = row[j] == "True"
+				} else {
+					entry[h] = row[j]
+				}
+			}
+			entries = append(entries, entry)
+		}
+
+		if len(entries) > 0 {
+			y, err := yaml.Marshal(entries)
+			if err != nil {
+				return fmt.Errorf("error marshalling yaml %w", err)
+			}
+			fmt.Fprint(w, string(y))
+		}
+
+		return nil
+	}
+}