Zo doen wijdat in oost

nodes/client/config.go

@@ -0,0 +1,177 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"time"
+)
+
+const (
+	DefaultBandwidthMB   = 500
+	DefaultMaxConcurrent = 2
+	DefaultMaxTunnels    = 2
+	ConfigDirName        = "devplace-node"
+	ConfigFileName       = "config.json"
+	UsageFileName        = "usage.json"
+	maxConfigBytes       = 64 * 1024
+)
+
+var hoursPattern = regexp.MustCompile(`^([01]\d|2[0-3]):[0-5]\d$`)
+
+type Config struct {
+	Server         string `json:"server"`
+	Secret         string `json:"secret"`
+	BandwidthMBDay int    `json:"bandwidth_mb_day"`
+	MaxConcurrent  int    `json:"max_concurrent"`
+	MaxTunnels     int    `json:"max_tunnels"`
+	ActiveFrom     string `json:"active_from"`
+	ActiveTo       string `json:"active_to"`
+	Timezone       string `json:"timezone"`
+}
+
+func DefaultConfig() Config {
+	return Config{
+		BandwidthMBDay: DefaultBandwidthMB,
+		MaxConcurrent:  DefaultMaxConcurrent,
+		MaxTunnels:     DefaultMaxTunnels,
+	}
+}
+
+func DefaultConfigPath() (string, error) {
+	base, err := os.UserConfigDir()
+	if err != nil {
+		return "", fmt.Errorf("cannot find the user config directory: %w", err)
+	}
+	return filepath.Join(base, ConfigDirName, ConfigFileName), nil
+}
+
+func (c Config) Validate() error {
+	parsed, err := url.Parse(c.Server)
+	if err != nil || (parsed.Scheme != "http" && parsed.Scheme != "https") || parsed.Host == "" {
+		return errors.New("server must be an http or https url such as https://devplace.net")
+	}
+	if !strings.HasPrefix(c.Secret, SecretPrefix) || len(c.Secret) < len(SecretPrefix)+8 {
+		return errors.New("secret must be a device secret starting with " + SecretPrefix)
+	}
+	if c.BandwidthMBDay < 1 || c.BandwidthMBDay > MaxDonorMBPerDay {
+		return fmt.Errorf("bandwidth_mb_day must be between 1 and %d", MaxDonorMBPerDay)
+	}
+	if c.MaxConcurrent < 1 || c.MaxConcurrent > MaxConcurrentCeiling {
+		return fmt.Errorf("max_concurrent must be between 1 and %d", MaxConcurrentCeiling)
+	}
+	if c.MaxTunnels < 1 || c.MaxTunnels > MaxTunnelsCeiling {
+		return fmt.Errorf("max_tunnels must be between 1 and %d", MaxTunnelsCeiling)
+	}
+	for _, value := range []string{c.ActiveFrom, c.ActiveTo} {
+		if value != "" && !hoursPattern.MatchString(value) {
+			return errors.New("active_from and active_to must be empty or HH:MM")
+		}
+	}
+	if (c.ActiveFrom == "") != (c.ActiveTo == "") {
+		return errors.New("active_from and active_to must be set together")
+	}
+	if _, err := c.Location(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c Config) Location() (*time.Location, error) {
+	if c.Timezone == "" {
+		return time.Local, nil
+	}
+	location, err := time.LoadLocation(c.Timezone)
+	if err != nil {
+		return nil, fmt.Errorf("timezone %q is not known", c.Timezone)
+	}
+	return location, nil
+}
+
+func (c Config) BaseURL() string {
+	return strings.TrimRight(c.Server, "/")
+}
+
+func LoadConfig(path string) (Config, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return Config{}, fmt.Errorf("no config at %s, run: devplace-node login --server URL --secret dpn_...", path)
+		}
+		return Config{}, err
+	}
+	defer file.Close()
+	config := DefaultConfig()
+	decoder := json.NewDecoder(&limitedReader{r: file, left: maxConfigBytes})
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&config); err != nil {
+		return Config{}, fmt.Errorf("config %s is invalid: %w", path, err)
+	}
+	if err := config.Validate(); err != nil {
+		return Config{}, fmt.Errorf("config %s is invalid: %w", path, err)
+	}
+	return config, nil
+}
+
+type limitedReader struct {
+	r    *os.File
+	left int
+}
+
+func (l *limitedReader) Read(p []byte) (int, error) {
+	if l.left <= 0 {
+		return 0, errors.New("file is too large")
+	}
+	if len(p) > l.left {
+		p = p[:l.left]
+	}
+	n, err := l.r.Read(p)
+	l.left -= n
+	return n, err
+}
+
+func SaveConfig(path string, config Config) error {
+	if err := config.Validate(); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(config, "", "  ")
+	if err != nil {
+		return err
+	}
+	return writeFileAtomic(path, append(data, '\n'))
+}
+
+func writeFileAtomic(path string, data []byte) error {
+	temp, err := os.CreateTemp(filepath.Dir(path), ".tmp-*")
+	if err != nil {
+		return err
+	}
+	name := temp.Name()
+	if err := temp.Chmod(0o600); err != nil {
+		temp.Close()
+		os.Remove(name)
+		return err
+	}
+	if _, err := temp.Write(data); err != nil {
+		temp.Close()
+		os.Remove(name)
+		return err
+	}
+	if err := temp.Close(); err != nil {
+		os.Remove(name)
+		return err
+	}
+	if err := os.Rename(name, path); err != nil {
+		os.Remove(name)
+		return err
+	}
+	return nil
+}