Add initial cluster config parser / converter

.gitignore

@@ -0,0 +1 @@
+.idea

rke-cluster-parser/cmd/parser/main.go

@@ -0,0 +1,188 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	rkecluster "github.com/rancher/rke/cluster"
+	rketypes "github.com/rancher/rke/types"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
+)
+
+func main() {
+	rootCmd := &cobra.Command{
+		Use:   "rcp",
+		Short: "rke-cluster-parser converts RKE cluster configs between JSON and YAML",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return cmd.Help()
+		},
+	}
+
+	toJSONOpts := toJSONOptions{}
+
+	toJSONCmd := &cobra.Command{
+		Use:   "to-json cluster.yaml [-o cluster.json]",
+		Short: "convert an RKE cluster config from YAML to JSON",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 1 {
+				return errors.New("only expected one input file argument")
+			}
+
+			inputPath, err := filepath.Abs(args[0])
+			if err != nil {
+				return fmt.Errorf("parse input file path: %v", err)
+			}
+			toJSONOpts.InputFile = inputPath
+
+			var src io.Reader
+			var dst io.Writer
+
+			if toJSONOpts.InputFile == "-" {
+				src = os.Stdin
+			} else {
+				if clusterFile, err := os.Open(toJSONOpts.InputFile); err != nil {
+					return fmt.Errorf("failed opening input file %s: %v", toJSONOpts.InputFile, err)
+				} else {
+					defer clusterFile.Close()
+					src = clusterFile
+				}
+			}
+
+			if toJSONOpts.OutputFile == "-" {
+				dst = os.Stdout
+			} else {
+				outputFile, err := os.Create(toJSONOpts.OutputFile)
+				if err != nil {
+					return fmt.Errorf("failed opening output file %s: %v", toJSONOpts.OutputFile, err)
+				}
+				defer outputFile.Close()
+				dst = outputFile
+			}
+
+			clusterYAML, err := ioutil.ReadAll(src)
+			if err != nil {
+				return fmt.Errorf("failed reading YAML contents: %v", err)
+			}
+
+			cluster, err := rkecluster.ParseConfig(string(clusterYAML))
+			if err != nil {
+				return fmt.Errorf("failed parsing YAML: %v", err)
+			}
+
+			clusterJSON, err := json.Marshal(cluster)
+			if err != nil {
+				return fmt.Errorf("failed converting cluster to JSON: %v", err)
+			}
+
+			if _, err := io.Copy(dst, bytes.NewBuffer(clusterJSON)); err != nil {
+				return fmt.Errorf("failed writing to output: %v", err)
+			}
+
+			return nil
+		},
+	}
+
+	toJSONCmd.Flags().StringVarP(
+		&toJSONOpts.OutputFile,
+		"output",
+		"o",
+		"-",
+		"specify output file; '-' outputs to stdout",
+	)
+
+	toYAMLOpts := toYAMLOptions{}
+
+	toYAMLCmd := &cobra.Command{
+		Use:     "to-yaml cluster.json [-o cluster.]",
+		Short:   "convert a cluster config from JSON to YAML",
+		Example: "to-yaml cluster.json",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 1 {
+				return errors.New("only expected one input file argument")
+			}
+
+			inputPath, err := filepath.Abs(args[0])
+			if err != nil {
+				return fmt.Errorf("parse input file path: %v", err)
+			}
+			toYAMLOpts.InputFile = inputPath
+
+			var src io.Reader
+			var dst io.Writer
+
+			if toYAMLOpts.InputFile == "-" {
+				src = os.Stdin
+			} else {
+				if clusterFile, err := os.Open(toYAMLOpts.InputFile); err != nil {
+					return fmt.Errorf("failed opening input file %s: %v", toJSONOpts.InputFile, err)
+				} else {
+					defer clusterFile.Close()
+					src = clusterFile
+				}
+			}
+
+			if toYAMLOpts.OutputFile == "-" {
+				dst = os.Stdout
+			} else {
+				outputFile, err := os.Create(toYAMLOpts.OutputFile)
+				if err != nil {
+					return fmt.Errorf("failed opening output file %s: %v", toYAMLOpts.OutputFile, err)
+				}
+				defer outputFile.Close()
+				dst = outputFile
+			}
+
+			clusterJSON, err := ioutil.ReadAll(src)
+			if err != nil {
+				return fmt.Errorf("failed reading JSON contents: %v", err)
+			}
+
+			cluster := &rketypes.RancherKubernetesEngineConfig{}
+			if err := json.Unmarshal(clusterJSON, &cluster); err != nil {
+				return fmt.Errorf("failed parsing JSON: %v", err)
+			}
+
+			clusterYAML, err := yaml.Marshal(cluster)
+			if err != nil {
+				return fmt.Errorf("failed converting cluster to YAML: %v", err)
+			}
+
+			if _, err := io.Copy(dst, bytes.NewBuffer(clusterYAML)); err != nil {
+				return fmt.Errorf("failed writing to output: %v", err)
+			}
+
+			return nil
+		},
+	}
+
+	toYAMLCmd.Flags().StringVarP(
+		&toYAMLOpts.OutputFile,
+		"output",
+		"o",
+		"-",
+		"specify output file; '-' outputs to stdout",
+	)
+
+	rootCmd.AddCommand(toJSONCmd, toYAMLCmd)
+
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println("error: " + err.Error())
+	}
+}
+
+type toJSONOptions struct {
+	InputFile  string
+	OutputFile string
+}
+
+type toYAMLOptions struct {
+	InputFile  string
+	OutputFile string
+}

rke-cluster-parser/go.mod

@@ -0,0 +1,11 @@
+module github.com/nikkelma/rke-rke2-migration/rke-cluster-parser
+
+go 1.15
+
+require (
+	github.com/rancher/rke v1.2.8
+	github.com/spf13/cobra v1.1.3
+	gopkg.in/yaml.v2 v2.4.0
+)
+
+replace k8s.io/client-go => k8s.io/client-go v0.20.0