feat: complete API-driven projects with infrastructure and business acceptance

database/database.go

@@ -14,13 +14,13 @@ import (
 )
 
 type Config struct {
-	Driver          string
-	DSN             string
-	MaxOpenConns    int
-	MaxIdleConns    int
-	ConnMaxLifetime time.Duration
-	ConnMaxIdleTime time.Duration
-	PingTimeout     time.Duration
+	Driver          string        `json:"driver"`
+	DSN             string        `json:"-"`
+	MaxOpenConns    int           `json:"maxOpenConns"`
+	MaxIdleConns    int           `json:"maxIdleConns"`
+	ConnMaxLifetime time.Duration `json:"connMaxLifetime"`
+	ConnMaxIdleTime time.Duration `json:"connMaxIdleTime"`
+	PingTimeout     time.Duration `json:"pingTimeout"`
 }
 
 func DefaultConfig() Config {
@@ -35,16 +35,25 @@ func DefaultConfig() Config {
 
 // ConfigFromEnv reads GO_OMNI_DB_* style settings. DSN is required.
 func ConfigFromEnv(prefix string) (Config, error) {
+	return ApplyEnv(DefaultConfig(), prefix)
+}
+
+// ApplyEnv overlays nonempty environment settings on file/default configuration.
+// DSN is environment-only when Config is decoded from JSON or YAML.
+func ApplyEnv(cfg Config, prefix string) (Config, error) {
 	prefix = strings.TrimSpace(prefix)
 	if prefix == "" {
 		prefix = "GO_OMNI_DB_"
 	}
-	cfg := DefaultConfig()
-	cfg.Driver = strings.TrimSpace(os.Getenv(prefix + "DRIVER"))
+	if value := strings.TrimSpace(os.Getenv(prefix + "DRIVER")); value != "" {
+		cfg.Driver = value
+	}
 	if cfg.Driver == "" {
 		cfg.Driver = "mysql"
 	}
-	cfg.DSN = strings.TrimSpace(os.Getenv(prefix + "DSN"))
+	if value := strings.TrimSpace(os.Getenv(prefix + "DSN")); value != "" {
+		cfg.DSN = value
+	}
 	if cfg.DSN == "" {
 		return Config{}, fmt.Errorf("%sDSN is required", prefix)
 	}