configbuilder

README

Go Config Loader

This is a config loader for Go tailored to my own needs. It is mainly intended to be used in Docker services that follow the standardized structure I am using.

Examples

Basic

The minimum needed is the following

type MyConfig struct {}

func main() {
    var cfg MyConfig
    
    err := cb.NewConfigBuilder[MyConfig]().Build(&cfg)
    if err != nil {
        panic(err)
    }   
}

This will run with all the defaults, meaning it will

• Load config from the json file config.json
• Add an environment specific config if it exists (and GO_ENV has a value), config.<env>.json
• Add version from the default version file
• Add environment variables
• Add any Docker secrets found in /var/run/secrets

Complete

type Version struct {
    Build string
    Version string
}

type MyConfig struct {
    Environment string
    MySetting   string `json:"mySetting"`
    MySecret    string `secret:"This_Is_My_Secret"`
    Version     *Version
}

func main() {
    var cfg MyConfig
    err := cb.NewConfigBuilder[MyConfig].
            WithDefaults(). // Explicitly set defaults to preserve them in case any other option is added
            // Alternatively add any option explicitly
            // WithJsonFile("my_json_file.json").
            // WithEnvironmentVariables().
            // WithDockerSecrets().
            Build(&cfg)
    if err != nil {
        panic(err)
    }   
}

This example assumes that the following files are available:

./my_json_config.json with content:

{
  "mySetting": "my value"
}

./version with content similar to:

version=1.0.0
build=local

And finally /var/run/secrets/This_Is_My_Secret

Code completion will show the complete list of available options.

Caveats

This is not really built to be used by others, so there is currently no support for other configuration file formats like yaml, toml, ini and so on. I might add this on request if anyone is interested.

Documentation

Index

• func NewConfigBuilder[T any]() interfaces.ConfigBuilder[T]

Functions

func NewConfigBuilder

func NewConfigBuilder[T any]() interfaces.ConfigBuilder[T]