A flexible and powerful Go configuration utility that loads environment variables into structs with support for various data types and customization options.
- Load environment variables into struct fields automatically
- Support for nested structs and pointers
- Customizable field name transformation
- Support for various data types:
- Basic types (string, bool, int, uint, float)
- Duration
- Slices (with custom separator)
- Maps (via JSON)
- Custom types implementing
encoding.TextUnmarshaler
- Configurable prefix and separators
- Tag-based field mapping with
envandaliastags - Anonymous struct embedding support
- Panic recovery for safe error handling
go get github.com/jkaveri/goconfigimport "github.com/jkaveri/goconfig"
type Config struct {
Host string `env:"HOST"`
Port int `env:"PORT"`
Timeout time.Duration
Debug bool
Numbers []int
Settings map[string]string
}
func main() {
var cfg Config
if err := goconfig.Load(&cfg); err != nil {
log.Fatal(err)
}
}The configtype package provides additional functionality for loading configuration from various file formats and handling special data types:
- Support for multiple configuration formats:
- JSON files
- YAML files
- TOML files
- Base64 encoding support for sensitive data
- Environment variable expansion in both file paths and configuration content
- Hot reloading capability for configuration files
- Generic type support for type-safe configuration loading
Example usage with configtype:
import (
"github.com/jkaveri/goconfig"
"github.com/jkaveri/goconfig/configtype"
)
type DBConfig struct {
Host string `json:"host"`
Port int `json:"port"`
Database string `json:"database"`
}
type AppConfig struct {
DB configtype.JSONFile[DBConfig] `env:"DB_CONFIG"`
Secret configtype.Base64 `env:"API_SECRET"`
}
func main() {
var cfg AppConfig
if err := goconfig.Load(&cfg); err != nil {
log.Fatal(err)
}
// Access configuration
fmt.Printf("Database: %s:%d/%s\n",
cfg.DB.Data.Host,
cfg.DB.Data.Port,
cfg.DB.Data.Database)
fmt.Printf("Secret: %s\n", cfg.Secret)
}import "github.com/jkaveri/goconfig"
type Config struct {
Host string `env:"HOST"`
Port int `env:"PORT"`
}
func main() {
var cfg Config
loader := goconfig.New(
goconfig.WithPrefix("APP"),
goconfig.WithSeparator("."),
goconfig.WithArraySeparator(";"),
)
if err := loader.LoadToStruct(&cfg); err != nil {
log.Fatal(err)
}
}env: Exact environment variable namealias: Alternative name for the field (will be combined with prefix)
type Config struct {
Host string `env:"SERVER_HOST"` // Uses exact name
Port int `alias:"server_port"` // Uses prefix + name
Timeout time.Duration // Uses field name transformed
}Given the following struct:
type Config struct {
Host string `env:"HOST"`
Port int
Timeout time.Duration
Debug bool
Numbers []int
Settings map[string]string
}The following environment variables would be loaded:
HOST=localhost
PORT=8080
TIMEOUT=5s
DEBUG=true
NUMBERS=1,2,3,4
SETTINGS={"key":"value"}WithPrefix(prefix string): Set prefix for all environment variablesWithSeparator(sep string): Set separator for nested fields (default: "_")WithArraySeparator(sep string): Set separator for array values (default: ",")WithFieldNameTransformer(fn func(string) string): Set custom field name transformation
MIT License