[#666] cmd/neofs-adm: Initial app structure with `config init` command

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

cmd/neofs-adm/internal/modules/config/config.go

@@ -0,0 +1,124 @@
+package config
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"text/template"
+
+	"github.com/nspcc-dev/neofs-node/pkg/innerring"
+	"github.com/spf13/cobra"
+)
+
+type configTemplate struct {
+	Endpoint      string
+	AlphabetDir   string
+	MaxObjectSize int
+	EpochDuration int
+	Glagolitics   []string
+}
+
+const configTxtTemplate = `rpc-endpoint: {{ .Endpoint}}
+alphabet-wallets: {{ .AlphabetDir}}
+network:
+  max_object_size: {{ .MaxObjectSize}}
+  epoch_duration: {{ .EpochDuration}}
+# if credentials section is omitted, then neofs-adm will require manual password input
+credentials:{{ range.Glagolitics}}
+  {{.}}: password{{end}}
+`
+
+func initConfig(cmd *cobra.Command, args []string) error {
+	configPath, err := readConfigPathFromArgs(cmd)
+	if err != nil {
+		return nil
+	}
+
+	pathDir := path.Dir(configPath)
+	err = os.MkdirAll(pathDir, 0700)
+	if err != nil {
+		return fmt.Errorf("create dir %s: %w", pathDir, err)
+	}
+
+	f, err := os.OpenFile(configPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC|os.O_SYNC, 0600)
+	if err != nil {
+		return fmt.Errorf("open %s: %w", configPath, err)
+	}
+	defer f.Close()
+
+	configText, err := generateConfigExample(pathDir, 7)
+	if err != nil {
+		return err
+	}
+
+	_, err = f.WriteString(configText)
+	if err != nil {
+		return fmt.Errorf("writing to %s: %w", configPath, err)
+	}
+
+	cmd.Printf("Initial config file saved to %s\n", configPath)
+
+	return nil
+}
+
+func readConfigPathFromArgs(cmd *cobra.Command) (string, error) {
+	configPath, err := cmd.Flags().GetString(configPathFlag)
+	if err != nil {
+		return "", err
+	}
+
+	if configPath != "" {
+		return configPath, nil
+	}
+
+	return defaultConfigPath()
+}
+
+func defaultConfigPath() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("getting home dir path: %w", err)
+	}
+
+	return path.Join(home, ".neofs", "adm", "config.yml"), nil
+}
+
+// generateConfigExample builds .yml representation of the config file. It is
+// easier to build it manually with template instead of using viper, because we
+// want to order records in specific order in file and, probably, provide
+// some comments as well.
+func generateConfigExample(appDir string, credSize int) (string, error) {
+	input := configTemplate{
+		Endpoint:      "https://neo.rpc.node:30333",
+		MaxObjectSize: 67108864, // 64 MiB
+		EpochDuration: 240,      // 1 hour with 15s per block
+		Glagolitics:   make([]string, 0, credSize),
+	}
+
+	appDir, err := filepath.Abs(appDir)
+	if err != nil {
+		return "", fmt.Errorf("making absolute path for %s: %w", appDir, err)
+	}
+	input.AlphabetDir = path.Join(appDir, "alphabet-wallets")
+
+	var i innerring.GlagoliticLetter
+	for i = 0; i < innerring.GlagoliticLetter(credSize); i++ {
+		input.Glagolitics = append(input.Glagolitics, i.String())
+	}
+
+	t, err := template.New("config.yml").Parse(configTxtTemplate)
+	if err != nil {
+		return "", fmt.Errorf("parsing config template: %w", err)
+	}
+
+	buf := bytes.NewBuffer(nil)
+
+	err = t.Execute(buf, input)
+	if err != nil {
+		return "", fmt.Errorf("generating config from tempalte: %w", err)
+	}
+
+	return buf.String(), nil
+}

cmd/neofs-adm/internal/modules/config/config_test.go

@@ -0,0 +1,40 @@
+package config
+
+import (
+	"bytes"
+	"path"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-node/pkg/innerring"
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGenerateConfigExample(t *testing.T) {
+	const (
+		n      = 10
+		appDir = "/home/example/.neofs"
+	)
+
+	configText, err := generateConfigExample(appDir, n)
+	require.NoError(t, err)
+
+	v := viper.New()
+	v.SetConfigType("yml")
+
+	require.NoError(t, v.ReadConfig(bytes.NewBufferString(configText)))
+
+	require.Equal(t, "https://neo.rpc.node:30333", v.GetString("rpc-endpoint"))
+	require.Equal(t, path.Join(appDir, "alphabet-wallets"), v.GetString("alphabet-wallets"))
+	require.Equal(t, 67108864, v.GetInt("network.max_object_size"))
+	require.Equal(t, 240, v.GetInt("network.epoch_duration"))
+
+	var i innerring.GlagoliticLetter
+	for i = 0; i < innerring.GlagoliticLetter(n); i++ {
+		key := "credentials." + i.String()
+		require.Equal(t, "password", v.GetString(key))
+	}
+
+	key := "credentials." + i.String()
+	require.Equal(t, "", v.GetString(key))
+}

cmd/neofs-adm/internal/modules/config/root.go

@@ -0,0 +1,29 @@
+package config
+
+import (
+	"github.com/spf13/cobra"
+)
+
+const configPathFlag = "path"
+
+var (
+	// RootCmd is a root command of config section.
+	RootCmd = &cobra.Command{
+		Use:   "config",
+		Short: "Section for neofs-adm config related commands.",
+	}
+
+	initCmd = &cobra.Command{
+		Use:   "init",
+		Short: "Initialize basic neofs-adm configuration file.",
+		Example: `neofs-adm config init
+neofs-adm config init --path .config/neofs-adm.yml`,
+		RunE: initConfig,
+	}
+)
+
+func init() {
+	RootCmd.AddCommand(initCmd)
+
+	initCmd.Flags().String(configPathFlag, "", "path to config (default ~/.neofs/adm/config.yml)")
+}

cmd/neofs-adm/internal/modules/root.go

@@ -0,0 +1,63 @@
+package modules
+
+import (
+	"fmt"
+
+	"github.com/nspcc-dev/neofs-node/cmd/neofs-adm/internal/modules/config"
+	"github.com/nspcc-dev/neofs-node/misc"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var (
+	rootCmd = &cobra.Command{
+		Use:   "neofs-adm",
+		Short: "NeoFS Administrative Tool",
+		Long: `NeoFS Administrative Tool provides functions to setup and
+manage NeoFS network deployment.`,
+		RunE:         entryPoint,
+		SilenceUsage: true,
+	}
+
+	configFlag = "config"
+)
+
+func init() {
+	cobra.OnInitialize(func() { initConfig(rootCmd) })
+	// we need to init viper config to bind viper and cobra configurations for
+	// rpc endpoint, alphabet wallet dir, key credentials, etc.
+
+	rootCmd.PersistentFlags().StringP(configFlag, "c", "", "config file")
+	rootCmd.Flags().Bool("version", false, "application version")
+
+	rootCmd.AddCommand(config.RootCmd)
+}
+
+func Execute() error {
+	return rootCmd.Execute()
+}
+
+func entryPoint(cmd *cobra.Command, args []string) error {
+	printVersion, err := cmd.Flags().GetBool("version")
+	if err == nil && printVersion {
+		fmt.Printf("Version: %s \nBuild: %s \nDebug: %s\n",
+			misc.Version,
+			misc.Build,
+			misc.Debug,
+		)
+		return nil
+	}
+
+	return cmd.Usage()
+}
+
+func initConfig(cmd *cobra.Command) {
+	configFile, err := cmd.Flags().GetString(configFlag)
+	if err != nil || configFile == "" {
+		return
+	}
+
+	viper.SetConfigType("yml")
+	viper.SetConfigFile(configFile)
+	_ = viper.ReadInConfig() // if config file is set but unavailable, ignore it
+}

cmd/neofs-adm/main.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"os"
+
+	"github.com/nspcc-dev/neofs-node/cmd/neofs-adm/internal/modules"
+)
+
+func main() {
+	if err := modules.Execute(); err != nil {
+		os.Exit(1)
+	}
+}