can now also merge resources and do a symmetric diff.

cmd/yamltool/diff.go

@@ -1,54 +1,13 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
-	yaml "github.com/goccy/go-yaml"
+	"github.com/goccy/go-yaml"
 	"github.com/spf13/cobra"
 	"os"
 	"reflect"
 )
 
-var VERBOSITY = 2
-
-func read(file string) []byte {
-	data, err := os.ReadFile(file)
-	if err != nil {
-		panic(err)
-	}
-	return data
-}
-
-func parse(data []byte) yaml.MapSlice {
-	var result yaml.MapSlice
-	decoder := yaml.NewDecoder(bytes.NewReader(data),
-		yaml.UseOrderedMap())
-	err := decoder.Decode(&result)
-	if err != nil {
-		panic(err)
-	}
-	return result
-}
-
-type TypeId int
-
-const (
-	Map TypeId = iota
-	Slice
-	Scalar
-)
-
-func Type(elem any) TypeId {
-	switch elem.(type) {
-	case yaml.MapSlice:
-		return Map
-	case []any:
-		return Slice
-	default:
-		return Scalar
-	}
-}
-
 // hack to be able to compare slices and dictionires that cannot be put into a map.
 func strval(v any) string {
 	return fmt.Sprintf("%v", v)
@@ -108,44 +67,41 @@ func subtract(yaml2 yaml.MapSlice, yaml1 yaml.MapSlice) yaml.MapSlice {
 	return res
 }
 
-func execute(cmd *cobra.Command, args []string) error {
+func diff(cmd *cobra.Command, args []string) error {
 	if len(args) != 2 {
-		return fmt.Errorf("Parameters expected")
+		return fmt.Errorf("Expected 2 files")
 	}
-	if VERBOSITY < 1 || VERBOSITY > 3 {
+	if VERBOSITY < 0 || VERBOSITY > 3 {
 		return fmt.Errorf("Array verbosity out of range")
 	}
-	file1 := os.Args[1]
-	file2 := os.Args[2]
+	file1 := args[0]
+	file2 := args[1]
 
 	yaml1 := parse(read(file1))
 	yaml2 := parse(read(file2))
 
-	yaml2 = subtract(yaml2, yaml1)
-
-	enc := yaml.NewEncoder(os.Stdout,
-		yaml.UseLiteralStyleIfMultiline(true),
-		yaml.Indent(2), // Set indentation
-		//yaml.UseOrderedMap(), // Preserve map order
-	)
-	err := enc.Encode(yaml2)
-	return err
-}
-
-func main() {
-
-	cmd := &cobra.Command{
-		Use:   "yamldiff <file1> <file2>",
-		Short: "Shows one-way difference between yaml files",
-		Long: `
-Shows the changes in <file2> compared to <file1>`,
-		RunE: func(cmd *cobra.Command, args []string) error {
-			return execute(cmd, args)
-		},
+	diff1 := subtract(yaml2, yaml1)
+	diff2 := make(yaml.MapSlice, 0)
+	if SYMMETRIC_DIFF {
+		diff2 = subtract(yaml1, yaml2)
 	}
 
-	cmd.PersistentFlags().IntVarP(&VERBOSITY, "array-output-level",
-		"v", 1, "Array output level: , 1: only show changed/added values, 2 show identical as <UNMODIFIED>, 3: show all values")
+	diff := diff1
+	if SYMMETRIC_DIFF {
+		diff = make(yaml.MapSlice, 0)
+		diff = append(diff,
+			yaml.MapItem{Key: "forward", Value: diff1},
+			yaml.MapItem{Key: "backward", Value: diff2},
+		)
+	}
 
-	cmd.Execute()
+	if VERBOSITY > 0 {
+		if err := encode(os.Stdout, diff); err != nil {
+			return err
+		}
+	}
+	if len(diff1) > 0 || len(diff2) > 0 {
+		os.Exit(1)
+	}
+	return nil
 }

cmd/yamltool/encode.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"github.com/goccy/go-yaml"
+	"io"
+	"os"
+)
+
+func encode(writer io.Writer, data any) error {
+	enc := yaml.NewEncoder(os.Stdout,
+		yaml.UseLiteralStyleIfMultiline(true),
+		yaml.Indent(2), // Set indentation
+		//yaml.UseOrderedMap(), // Preserve map order
+	)
+	return enc.Encode(data)
+}

cmd/yamltool/merge.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"github.com/goccy/go-yaml"
+	"github.com/spf13/cobra"
+	"os"
+	"reflect"
+)
+
+type MyMap yaml.MapSlice
+
+func (m *MyMap) Set(key any, value any) {
+	for i := range len(*m) {
+		if (*m)[i].Key == key {
+			(*m)[i].Value = value
+			return
+		}
+	}
+	*m = append(*m, yaml.MapItem{Key: key, Value: value})
+}
+
+func (m MyMap) Get(key any) any {
+	for _, item := range m {
+		if item.Key == key {
+			return item.Value
+		}
+	}
+	return nil
+}
+
+func mergeMap(yaml1 yaml.MapSlice, yaml2 yaml.MapSlice) yaml.MapSlice {
+	res := MyMap(yaml1)
+
+	for _, item := range yaml2 {
+		initialValue := res.Get(item.Key)
+		value := item.Value
+		switch {
+		case initialValue != nil:
+			if reflect.TypeOf(initialValue) == reflect.TypeOf(yaml.MapSlice{}) &&
+				reflect.TypeOf(value) == reflect.TypeOf(yaml.MapSlice{}) {
+				mergedMap := mergeMap(initialValue.(yaml.MapSlice), value.(yaml.MapSlice))
+				res.Set(item.Key, mergedMap)
+			} else {
+				res.Set(item.Key, item.Value)
+			}
+		default:
+			res.Set(item.Key, item.Value)
+		}
+	}
+	return yaml.MapSlice(res)
+}
+
+func merge(cmd *cobra.Command, args []string) error {
+	res := make(yaml.MapSlice, 0)
+	for _, arg := range args {
+		config := parse(read(arg))
+		res = mergeMap(res, config)
+	}
+	encode(os.Stdout, res)
+	return nil
+}

cmd/yamltool/parse.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"bytes"
+	"github.com/goccy/go-yaml"
+	"os"
+)
+
+func read(file string) []byte {
+	data, err := os.ReadFile(file)
+	if err != nil {
+		panic(err)
+	}
+	return data
+}
+
+func parse(data []byte) yaml.MapSlice {
+	var result yaml.MapSlice
+	decoder := yaml.NewDecoder(bytes.NewReader(data),
+		yaml.UseOrderedMap())
+	err := decoder.Decode(&result)
+	if err != nil {
+		panic(err)
+	}
+	return result
+}

cmd/yamltool/yamltool.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	yaml "github.com/goccy/go-yaml"
+	"github.com/spf13/cobra"
+)
+
+var VERBOSITY = 3
+var SYMMETRIC_DIFF = false
+
+type TypeId int
+
+const (
+	Map TypeId = iota
+	Slice
+	Scalar
+)
+
+func Type(elem any) TypeId {
+	switch elem.(type) {
+	case yaml.MapSlice:
+		return Map
+	case []any:
+		return Slice
+	default:
+		return Scalar
+	}
+}
+
+func main() {
+
+	cmd := &cobra.Command{
+		Use:   "yamltool",
+		Short: "Shows one-way difference between yaml files",
+		Long: `
+Shows the changes in <file2> compared to <file1>`,
+	}
+
+	diff := &cobra.Command{
+		Use:   "diff [file1] [file2]",
+		Short: "Shows one-way difference between yaml files",
+		Long: `
+Shows the additions and modifications in <file2> compared to <file1>`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return diff(cmd, args)
+		},
+	}
+	cmd.AddCommand(diff)
+
+	merge := &cobra.Command{
+		Use:   "merge [file1] ... [fileN]",
+		Short: "Merge yaml files.",
+		Long:  `Changes will be merged into the first file, so later files override earlier ones`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return merge(cmd, args)
+		},
+	}
+	cmd.AddCommand(merge)
+
+	diff.PersistentFlags().IntVarP(&VERBOSITY, "array-output-level",
+		"v", 3, `Array output level: ,
+	0: no output, only exit status,
+	1: only show changed/added values, 
+	2: show identical as <UNMODIFIED>, 
+	3: show all values`)
+	diff.Flags().BoolVarP(&SYMMETRIC_DIFF, "symmetric-diff",
+		"s", false, `Symmetric difference, compare in both directions`)
+
+	cmd.Execute()
+}

go.mod

@@ -1,6 +1,6 @@
 module git.wamblee.org/public/gotools
 
-go 1.23.3
+go 1.23.4
 
 require (
 	github.com/goccy/go-yaml v1.15.13