configs

README

Configs Module

A configuration management module built on Viper, providing unified configuration loading from files and environment variables.

Features

• Load configuration from TOML files
• Environment variable support with automatic prefix
• Programmatic configuration override
• Print all settings for debugging

Installation

go get github.com/weedbox/common-modules/configs

Quick Start

Basic Usage

package main

import (
    "github.com/weedbox/common-modules/configs"
    "go.uber.org/fx"
)

func main() {
    // Create config with environment variable prefix
    config := configs.NewConfig("MYAPP")

    fx.New(
        fx.Supply(config),
        // ... other modules
    ).Run()
}

Setting Default Configurations

config := configs.NewConfig("MYAPP")

// Set default values (won't override existing values)
config.SetConfigs(map[string]interface{}{
    "http_server.host": "0.0.0.0",
    "http_server.port": 8080,
    "database.host":    "localhost",
    "database.port":    5432,
})

Print All Settings

config := configs.NewConfig("MYAPP")

// Print all current configurations
config.PrintAllSettings()

Output:

[List of current configs]
http_server.host=0.0.0.0
http_server.port=8080
database.host=localhost
database.port=5432

Configuration Sources

The module loads configuration from multiple sources in the following priority order (highest to lowest):

1. Environment Variables - Prefixed with the specified prefix (e.g., MYAPP_HTTP_SERVER_PORT)
2. Configuration File - config.toml in ./ or ./configs/ directory
3. Programmatic Defaults - Set via SetConfigs()

Environment Variables

Environment variables are automatically mapped using the prefix:

# With prefix "MYAPP", these environment variables:
export MYAPP_HTTP_SERVER_HOST=0.0.0.0
export MYAPP_HTTP_SERVER_PORT=8080
export MYAPP_DATABASE_HOST=localhost

# Map to these config keys:
# http_server.host
# http_server.port
# database.host

Key transformation rules:

• Prefix is prepended (e.g., MYAPP_)
• Dots (.) become underscores (_)
• Hyphens (-) become underscores (_)

TOML Configuration File

Create a config.toml file in the project root or ./configs/ directory:

[http_server]
host = "0.0.0.0"
port = 8080

[database]
host = "localhost"
port = 5432
dbname = "myapp"
user = "postgres"
password = "secret"

API Reference

Config

NewConfig(prefix string) *Config

Creates a new Config instance and initializes Viper with the specified environment variable prefix.

• prefix: Prefix for environment variables (e.g., "MYAPP" results in "MYAPP_*" env vars)

SetConfigs(configs map[string]interface{})

Sets configuration values only if they are not already set. Useful for providing default values.

config.SetConfigs(map[string]interface{}{
    "server.port": 8080,
    "server.host": "localhost",
})

GetAllSettings() map[string]interface{}

Returns all current configuration settings as a nested map.

PrintAllSettings()

Prints all configuration settings to stdout in a flat key=value format.

License

Apache License 2.0

Documentation

Index

• type Config
  • func NewConfig(prefix string) *Config
  • func (config *Config) GetAllSettings() map[string]interface{}
  • func (config *Config) PrintAllSettings()
  • func (config *Config) PrintSettings(scope string, settings map[string]interface{})
  • func (config *Config) SetConfigs(configs map[string]interface{})

Types

type Config

type Config struct {
}

func NewConfig

func NewConfig(prefix string) *Config

func (*Config) GetAllSettings

func (config *Config) GetAllSettings() map[string]interface{}

func (*Config) PrintAllSettings

func (config *Config) PrintAllSettings()

func (*Config) PrintSettings

func (config *Config) PrintSettings(scope string, settings map[string]interface{})

func (*Config) SetConfigs

func (config *Config) SetConfigs(configs map[string]interface{})