diff for Kubernetes Resources

main.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"os"

	"github.com/Cside/jsondiff"
	k8syaml "k8s.io/apimachinery/pkg/util/yaml"
	"sigs.k8s.io/yaml"
)

func readYaml(filename string) (map[string][]byte, error) {
	f, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	result := make(map[string][]byte)
	reader := k8syaml.NewYAMLReader(bufio.NewReader(f))
	for {
		data, err := reader.Read()
		if err == io.EOF {
			break
		} else if err != nil {
			return nil, err
		}

		var res struct {
			Kind     string `json:"kind"`
			Metadata struct {
				Name      string `json:"name"`
				Namespace string `json:"namespace"`
			} `json:"metadata"`
		}
		err = yaml.Unmarshal(data, &res)
		if err != nil {
			return nil, err
		}
		result[fmt.Sprintf("%s:%s:%s", res.Kind, res.Metadata.Namespace, res.Metadata.Name)] = data
	}
	return result, nil
}

func printDiff(data1, data2 map[string][]byte) error {
	for k, v1 := range data1 {
		if v2, ok := data2[k]; ok {
			j1, err := yaml.YAMLToJSON(v1)
			if err != nil {
				return err
			}
			j2, err := yaml.YAMLToJSON(v2)
			if err != nil {
				return err
			}
			if diff := jsondiff.Diff(j1, j2); diff != "" {
				fmt.Printf("diff: %s\n%s\n", k, diff)
			}
			delete(data1, k)
			delete(data2, k)
		}
	}
	for k, v1 := range data1 {
		j1, err := yaml.YAMLToJSON(v1)
		if err != nil {
			return err
		}
		if diff := jsondiff.Diff(j1, []byte("{}")); diff != "" {
			fmt.Printf("diff: %s\n%s\n", k, diff)
		}
	}
	for k, v2 := range data2 {
		j2, err := yaml.YAMLToJSON(v2)
		if err != nil {
			return err
		}
		if diff := jsondiff.Diff([]byte("{}"), j2); diff != "" {
			fmt.Printf("diff: %s\n%s\n", k, diff)
		}
	}
	return nil
}

func main() {
	if len(os.Args) != 3 {
		fmt.Println("usage: kdiff src dst")
		os.Exit(1)
	}
	data1, err := readYaml(os.Args[1])
	if err != nil {
		log.Fatal(err)
		os.Exit(1)
	}
	data2, err := readYaml(os.Args[2])
	if err != nil {
		log.Fatal(err)
		os.Exit(1)
	}

	err = printDiff(data1, data2)
	if err != nil {
		log.Fatal(err)
		os.Exit(1)
	}
}