feat: enrol nodes with a one-time setup token

cmd/init.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/netip"
 	"os"
+	"strings"
 
 	"github.com/encodeous/nylon/state"
 	"github.com/goccy/go-yaml"
@@ -28,6 +29,12 @@ type initOptions struct {
 	preDown          []string
 	postUp           []string
 	postDown         []string
+	serve            bool
+	connect          string
+	token            string
+	central          string
+	addresses        []string
+	prefixes         []string
 }
 
 func newInitCmd() *cobra.Command {
@@ -38,39 +45,19 @@ func newInitCmd() *cobra.Command {
 		GroupID: "init",
 		Args:    cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, _ []string) error {
-			cfg, err := buildNodeConfig(opts)
-			if err != nil {
-				return err
+			cmd.SilenceUsage = true
+			if opts.serve {
+				return runInitServe(cmd, opts)
 			}
-
-			data, err := yaml.Marshal(cfg)
-			if err != nil {
-				return fmt.Errorf("encode node config: %w", err)
+			if opts.connect != "" {
+				return runInitConnect(cmd, opts)
 			}
-
-			flags := os.O_WRONLY | os.O_CREATE
-			if opts.force {
-				flags |= os.O_TRUNC
-			} else {
-				flags |= os.O_EXCL
-			}
-			file, err := os.OpenFile(opts.output, flags, 0o600)
+			cfg, err := buildNodeConfig(opts)
 			if err != nil {
-				if errors.Is(err, os.ErrExist) {
-					return fmt.Errorf("%s already exists (use --force to overwrite)", opts.output)
-				}
-				return fmt.Errorf("create %s: %w", opts.output, err)
-			}
-			if err = file.Chmod(0o600); err != nil {
-				_ = file.Close()
-				return fmt.Errorf("secure %s: %w", opts.output, err)
-			}
-			if _, err = file.Write(data); err != nil {
-				_ = file.Close()
-				return fmt.Errorf("write %s: %w", opts.output, err)
+				return err
 			}
-			if err = file.Close(); err != nil {
-				return fmt.Errorf("close %s: %w", opts.output, err)
+			if err = writeNodeConfig(cfg, opts.output, opts.force); err != nil {
+				return err
 			}
 
 			publicKey, err := cfg.Key.Pubkey().MarshalText()
@@ -83,8 +70,8 @@ func newInitCmd() *cobra.Command {
 	}
 
 	flags := cmd.Flags()
-	flags.StringVar(&opts.id, "id", "", "Unique node ID (required)")
-	flags.Uint16Var(&opts.port, "port", 57175, "UDP port Nylon listens on")
+	flags.StringVar(&opts.id, "id", "", "Unique node ID (defaults to hostname)")
+	flags.Uint16Var(&opts.port, "port", state.DefaultPort, "UDP port Nylon listens on")
 	flags.StringVar(&opts.key, "key", "", "Existing private key (a new key is generated if omitted)")
 	flags.StringVarP(&opts.output, "output", "o", DefaultNodeConfigPath, "Node config output path")
 	flags.BoolVar(&opts.force, "force", false, "Overwrite the output file if it exists")
@@ -99,9 +86,53 @@ func newInitCmd() *cobra.Command {
 	flags.StringSliceVar(&opts.preDown, "pre-down", nil, "Command to run before interface shutdown (repeatable)")
 	flags.StringSliceVar(&opts.postUp, "post-up", nil, "Command to run after interface startup (repeatable)")
 	flags.StringSliceVar(&opts.postDown, "post-down", nil, "Command to run after interface shutdown (repeatable)")
+	flags.BoolVar(&opts.serve, "serve", false, "Print a setup token and wait for a node to join with --connect")
+	flags.StringVar(&opts.connect, "connect", "", "Join the network through a node running --serve (host[:port])")
+	flags.StringVar(&opts.token, "token", "", "Setup token printed by --serve")
+	flags.StringVarP(&opts.central, "config", "c", DefaultConfigPath, "Central config path used by --serve and --connect")
+	flags.StringSliceVar(&opts.addresses, "address", nil, "Nylon address for this node in central config (repeatable)")
+	flags.StringSliceVar(&opts.prefixes, "prefix", nil, "IP prefix this node advertises in central config (repeatable)")
+	cmd.MarkFlagsMutuallyExclusive("serve", "connect")
+	cmd.MarkFlagsRequiredTogether("connect", "token")
 	return cmd
 }
 
+func writeNodeConfig(cfg *state.LocalCfg, path string, force bool) error {
+	data, err := yaml.Marshal(cfg)
+	if err != nil {
+		return fmt.Errorf("encode node config: %w", err)
+	}
+	return writeSecretFile(path, data, force)
+}
+
+func writeSecretFile(path string, data []byte, force bool) error {
+	flags := os.O_WRONLY | os.O_CREATE
+	if force {
+		flags |= os.O_TRUNC
+	} else {
+		flags |= os.O_EXCL
+	}
+	file, err := os.OpenFile(path, flags, 0o600)
+	if err != nil {
+		if errors.Is(err, os.ErrExist) {
+			return fmt.Errorf("%s already exists (use --force to overwrite)", path)
+		}
+		return fmt.Errorf("create %s: %w", path, err)
+	}
+	if err = file.Chmod(0o600); err != nil {
+		_ = file.Close()
+		return fmt.Errorf("secure %s: %w", path, err)
+	}
+	if _, err = file.Write(data); err != nil {
+		_ = file.Close()
+		return fmt.Errorf("write %s: %w", path, err)
+	}
+	if err = file.Close(); err != nil {
+		return fmt.Errorf("close %s: %w", path, err)
+	}
+	return nil
+}
+
 func buildNodeConfig(opts initOptions) (*state.LocalCfg, error) {
 	privateKey := state.GenerateKey()
 	if opts.key != "" {
@@ -110,9 +141,18 @@ func buildNodeConfig(opts initOptions) (*state.LocalCfg, error) {
 		}
 	}
 
+	id := opts.id
+	if id == "" {
+		host, err := os.Hostname()
+		if err != nil {
+			return nil, fmt.Errorf("--id is required: %w", err)
+		}
+		id = strings.ToLower(host)
+	}
+
 	cfg := &state.LocalCfg{
 		Key:              privateKey,
-		Id:               state.NodeId(opts.id),
+		Id:               state.NodeId(id),
 		Port:             opts.port,
 		UseSystemRouting: opts.useSystemRouting,
 		NoNetConfigure:   opts.noNetConfigure,
@@ -139,6 +179,18 @@ func buildNodeConfig(opts initOptions) (*state.LocalCfg, error) {
 	return cfg, nil
 }
 
+func parseAddrs(values []string) ([]netip.Addr, error) {
+	addrs := make([]netip.Addr, 0, len(values))
+	for _, value := range values {
+		addr, err := netip.ParseAddr(value)
+		if err != nil {
+			return nil, fmt.Errorf("%q: %w", value, err)
+		}
+		addrs = append(addrs, addr)
+	}
+	return addrs, nil
+}
+
 func parsePrefixes(values []string) ([]netip.Prefix, error) {
 	prefixes := make([]netip.Prefix, 0, len(values))
 	for _, value := range values {