feat: bootstrap control plane app skeleton

internal/config/config.go

@@ -0,0 +1,82 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+const (
+	EnvListenAddr = "SUB2API_CRM_LISTEN_ADDR"
+	EnvSQLiteDSN  = "SUB2API_CRM_SQLITE_DSN"
+	EnvAdminToken = "SUB2API_CRM_ADMIN_TOKEN"
+
+	DefaultListenAddr = ":8080"
+	DefaultSQLiteDSN  = "file:sub2api-cn-relay-manager.db?_foreign_keys=on&_busy_timeout=5000"
+)
+
+type ServerConfig struct {
+	ListenAddr string
+}
+
+type DatabaseConfig struct {
+	SQLiteDSN string
+}
+
+type StartupConfig struct {
+	Server   ServerConfig
+	Database DatabaseConfig
+}
+
+func LoadStartupFromEnv() (StartupConfig, error) {
+	return loadStartupFromLookupEnv(os.LookupEnv)
+}
+
+func loadStartupFromLookupEnv(lookup func(string) (string, bool)) (StartupConfig, error) {
+	cfg := StartupConfig{
+		Server: ServerConfig{
+			ListenAddr: readOptionalEnv(lookup, EnvListenAddr, DefaultListenAddr),
+		},
+		Database: DatabaseConfig{
+			SQLiteDSN: readOptionalEnv(lookup, EnvSQLiteDSN, DefaultSQLiteDSN),
+		},
+	}
+
+	return cfg, nil
+}
+
+func LoadAdminTokenFromEnv() (string, error) {
+	return loadAdminTokenFromLookupEnv(os.LookupEnv)
+}
+
+func loadAdminTokenFromLookupEnv(lookup func(string) (string, bool)) (string, error) {
+	token := strings.TrimSpace(readRequiredEnv(lookup, EnvAdminToken))
+	if token == "" {
+		return "", fmt.Errorf("%s is required", EnvAdminToken)
+	}
+
+	return token, nil
+}
+
+func readOptionalEnv(lookup func(string) (string, bool), key string, defaultValue string) string {
+	value, ok := lookup(key)
+	if !ok {
+		return defaultValue
+	}
+
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return defaultValue
+	}
+
+	return value
+}
+
+func readRequiredEnv(lookup func(string) (string, bool), key string) string {
+	value, ok := lookup(key)
+	if !ok {
+		return ""
+	}
+
+	return value
+}