feat: load backend config from yaml

backend/etc/agent.dev.yaml

@@ -0,0 +1,7 @@
+env: development
+port: "8080"
+database_url: "postgres://agent:agent@localhost:5432/agent?sslmode=disable"
+storage_dir: "./data/files"
+auth_secret: "development-auth-secret-change-me"
+system_ai_key: ""
+ai_key_encryption_secret: "development-ai-key-secret-change-me"

backend/internal/config/config.go

@@ -1,32 +1,44 @@
 package config
 
-import "os"
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
 
 type Config struct {
-	Env                   string
-	Port                  string
-	DatabaseURL           string
-	StorageDir            string
-	AuthSecret            string
-	SystemAIKey           string
-	AIKeyEncryptionSecret string
+	Env                   string `yaml:"env"`
+	Port                  string `yaml:"port"`
+	DatabaseURL           string `yaml:"database_url"`
+	StorageDir            string `yaml:"storage_dir"`
+	AuthSecret            string `yaml:"auth_secret"`
+	SystemAIKey           string `yaml:"system_ai_key"`
+	AIKeyEncryptionSecret string `yaml:"ai_key_encryption_secret"`
 }
 
 func Load() Config {
-	return Config{
-		Env:                   getenv("APP_ENV", "development"),
-		Port:                  getenv("PORT", "8080"),
-		DatabaseURL:           getenv("DATABASE_URL", "postgres://agent:agent@localhost:5432/agent?sslmode=disable"),
-		StorageDir:            getenv("STORAGE_DIR", "./data/files"),
-		AuthSecret:            getenv("AUTH_SECRET", "development-auth-secret-change-me"),
-		SystemAIKey:           os.Getenv("SYSTEM_AI_KEY"),
-		AIKeyEncryptionSecret: getenv("AI_KEY_ENCRYPTION_SECRET", "development-ai-key-secret-change-me"),
+	cfg, err := LoadFromDir("etc")
+	if err != nil {
+		panic(err)
 	}
+	return cfg
 }
 
-func getenv(key string, fallback string) string {
-	if value := os.Getenv(key); value != "" {
-		return value
+func LoadFromDir(configDir string) (Config, error) {
+	mode := strings.TrimSpace(os.Getenv("SENLIN_APP_MODE"))
+	if mode == "" {
+		mode = "dev"
 	}
-	return fallback
+	path := filepath.Join(configDir, "agent."+strings.ToLower(mode)+".yaml")
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return Config{}, err
+	}
+	var cfg Config
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return Config{}, err
+	}
+	return cfg, nil
 }

backend/internal/config/config_test.go

@@ -0,0 +1,57 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadFromDirDefaultsToDevYAML(t *testing.T) {
+	configDir := t.TempDir()
+	writeConfig(t, configDir, "agent.dev.yaml", "development", "18080", "postgres://dev", "./dev-files", "dev-auth", "dev-system", "dev-ai")
+	t.Setenv("SENLIN_APP_MODE", "")
+	t.Setenv("PORT", "9999")
+
+	cfg, err := LoadFromDir(configDir)
+
+	require.NoError(t, err)
+	require.Equal(t, "development", cfg.Env)
+	require.Equal(t, "18080", cfg.Port)
+	require.Equal(t, "postgres://dev", cfg.DatabaseURL)
+	require.Equal(t, "./dev-files", cfg.StorageDir)
+	require.Equal(t, "dev-auth", cfg.AuthSecret)
+	require.Equal(t, "dev-system", cfg.SystemAIKey)
+	require.Equal(t, "dev-ai", cfg.AIKeyEncryptionSecret)
+}
+
+func TestLoadFromDirUsesSENLINAppMode(t *testing.T) {
+	configDir := t.TempDir()
+	writeConfig(t, configDir, "agent.dev.yaml", "development", "18080", "postgres://dev", "./dev-files", "dev-auth", "", "dev-ai")
+	writeConfig(t, configDir, "agent.prod.yaml", "production", "80", "postgres://prod", "/data/files", "prod-auth", "prod-system", "prod-ai")
+	t.Setenv("SENLIN_APP_MODE", "prod")
+
+	cfg, err := LoadFromDir(configDir)
+
+	require.NoError(t, err)
+	require.Equal(t, "production", cfg.Env)
+	require.Equal(t, "80", cfg.Port)
+	require.Equal(t, "postgres://prod", cfg.DatabaseURL)
+	require.Equal(t, "/data/files", cfg.StorageDir)
+	require.Equal(t, "prod-auth", cfg.AuthSecret)
+	require.Equal(t, "prod-system", cfg.SystemAIKey)
+	require.Equal(t, "prod-ai", cfg.AIKeyEncryptionSecret)
+}
+
+func writeConfig(t *testing.T, dir string, name string, env string, port string, databaseURL string, storageDir string, authSecret string, systemAIKey string, aiKeySecret string) {
+	t.Helper()
+	content := []byte("env: " + env + "\n" +
+		"port: \"" + port + "\"\n" +
+		"database_url: \"" + databaseURL + "\"\n" +
+		"storage_dir: \"" + storageDir + "\"\n" +
+		"auth_secret: \"" + authSecret + "\"\n" +
+		"system_ai_key: \"" + systemAIKey + "\"\n" +
+		"ai_key_encryption_secret: \"" + aiKeySecret + "\"\n")
+	require.NoError(t, os.WriteFile(filepath.Join(dir, name), content, 0o600))
+}