initial commit

config/config.go

@@ -0,0 +1,153 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"reflect"
+	"strings"
+
+	"github.com/spf13/pflag"
+)
+
+type ConfigDef struct {
+	Key         string
+	Env         string
+	Default     string
+	Description string
+}
+
+type BaseConfig struct {
+	ServerAddress string `json:"server" description:"Conduit server address" default:"http://localhost:8080"`
+	APIKey        string `json:"api_key" description:"API Key for the conduit API"`
+}
+
+func (c *BaseConfig) Validate() error {
+	if c.APIKey == "" {
+		return errors.New("api_key is required")
+	}
+	if c.ServerAddress == "" {
+		return errors.New("server is required")
+	}
+	if _, err := url.Parse(c.ServerAddress); err != nil {
+		return fmt.Errorf("server is invalid: %w", err)
+	}
+	return nil
+}
+
+type ServerConfig struct {
+	BaseConfig
+	BindAddress string `json:"bind" default:"0.0.0.0:8080" description:"Address the conduit server listens on"`
+}
+
+type ClientConfig struct {
+	BaseConfig
+	TunnelName   string `json:"name" description:"Tunnel name"`
+	TunnelTarget string `json:"target" description:"Tunnel target address"`
+}
+
+func (c *ClientConfig) Validate() error {
+	if err := c.BaseConfig.Validate(); err != nil {
+		return err
+	}
+	if c.TunnelTarget == "" {
+		return fmt.Errorf("target is required")
+	}
+	return nil
+}
+
+func GetServerConfig(cmdFlags *pflag.FlagSet) (*ServerConfig, error) {
+	defs := GetConfigDefs[ServerConfig]()
+
+	cfgValues := make(map[string]string)
+	for _, def := range defs {
+		cfgValues[def.Key] = getConfigValue(cmdFlags, def)
+	}
+
+	cfg := &ServerConfig{
+		BaseConfig: BaseConfig{
+			ServerAddress: cfgValues["server"],
+			APIKey:        cfgValues["api_key"],
+		},
+		BindAddress: cfgValues["bind"],
+	}
+
+	return cfg, cfg.Validate()
+}
+
+func GetClientConfig(cmdFlags *pflag.FlagSet) (*ClientConfig, error) {
+	defs := GetConfigDefs[ClientConfig]()
+
+	cfgValues := make(map[string]string)
+	for _, def := range defs {
+		cfgValues[def.Key] = getConfigValue(cmdFlags, def)
+	}
+
+	cfg := &ClientConfig{
+		BaseConfig: BaseConfig{
+			ServerAddress: cfgValues["server"],
+			APIKey:        cfgValues["api_key"],
+		},
+		TunnelName:   cfgValues["name"],
+		TunnelTarget: cfgValues["target"],
+	}
+
+	return cfg, cfg.Validate()
+}
+
+func GetConfigDefs[T ServerConfig | ClientConfig]() []ConfigDef {
+	var defs []ConfigDef
+	processFields(reflect.TypeFor[T](), &defs)
+	return defs
+}
+
+func getConfigValue(cmdFlags *pflag.FlagSet, def ConfigDef) string {
+	// 1. Get Flags First
+	if cmdFlags != nil {
+		if val, err := cmdFlags.GetString(def.Key); err == nil && val != "" {
+			return val
+		}
+	}
+
+	// 2. Environment Variables Next
+	if envVal := os.Getenv(def.Env); envVal != "" {
+		return envVal
+	}
+
+	// 3. Defaults Last
+	return def.Default
+}
+
+func processFields(t reflect.Type, defs *[]ConfigDef) {
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+
+		// Process Embedded (BaseConfig)
+		if field.Anonymous {
+			processFields(field.Type, defs)
+			continue
+		}
+
+		// Extract Struct Tags
+		jsonTag := field.Tag.Get("json")
+		defaultTag := field.Tag.Get("default")
+		descriptionTag := field.Tag.Get("description")
+
+		// Skip JSON Fields
+		if jsonTag == "" {
+			continue
+		}
+
+		// Get Key & Env
+		key := strings.Split(jsonTag, ",")[0]
+		env := "CONDUIT_" + strings.ToUpper(key)
+
+		*defs = append(*defs, ConfigDef{
+			Key:         key,
+			Env:         env,
+			Default:     defaultTag,
+			Description: descriptionTag,
+		})
+	}
+}