config

Documentation

Index

• Variables
• type Config
  • func Init(name string, version *semver.SemVer, data any, fns ValidatorsMap, ...) Config
  • func NewConfig(name string, version *semver.SemVer, data any, fns ValidatorsMap, ...) Config
  • func NewDefaultConfig(required bool) Config
• type ValidatorsMap

Variables

var (
	ErrValidatorNotFound  = errors.Base("validator not found")
	ErrIncorrectArguments = errors.Base("incorrect arguments")
	ErrValidationFailed   = errors.Base("validation failed")
)

var (
	ErrInvalidObject = errors.Base("invalid configuration object")
)

Types

type Config

type Config interface {
	// Have we detected `-debug` in the CLI arguments?
	IsDebug() bool

	// Returns the application name.
	Name() string

	// Returns the application's version.
	Version() *semver.SemVer

	// Return the pathname to a logfile passed via the `-log` CLI
	// argument.
	//
	// Will be empty if no log file has been specified.
	LogFile() string

	// Return the pathname to the configuration file passed via the
	// '-config' CLI argument.
	//
	// Will be empty if no configuration file has been specified.
	ConfFile() string

	// Add a validator function for an option named `name`.  `fn` must be
	// a function that can be funcalled and must return either `nil` or an
	// error.
	AddValidator(name string, fn any)

	// Return the string representation of this object.
	String() string

	// Perform validation on the application configuration structure that
	// is parsed from the config file.
	Validate() []error

	// Add a Boolean CLI flag.
	AddBoolFlag(p *bool, name string, value bool, usage string)

	// Add a 64-bit floating point CLI flag.
	AddFloat64Flag(p *float64, name string, value float64, usage string)

	// Add a 32-bit signed integer CLI flag.
	AddIntFlag(p *int, name string, value int, usage string)

	// Add a 64-bit signed integer CLI flag.
	AddInt64Flag(p *int64, name string, value int64, usage string)

	// Add a string CLI flag.
	AddStringFlag(p *string, name string, value string, usage string)

	// Add a 32-bit unsigned integer CLI flag.
	AddUintFlag(p *uint, name string, value uint, usage string)

	// Add a 64-bit unsigned integer CLI flag.
	AddUint64Flag(p *uint64, name string, value uint64, usage string)

	// Look up a given flag value.  Looks for a flag called `name`.
	LookupFlag(name string) *flag.Flag

	// Parse CLI arguments.
	Parse()
}

Config structure.

User-defined configuration options are placed into `App`, with any custom validators stuffed into `Validators`.

The magic happens like this.

1) Define the structure you want your options to live in:

```go

type Options struct {
    Option1 string `json:"option1" config_validator:"ValidateOption1"
    // ...
}

```

The `config_validator` tag informs the Config module that you wish to validate the `Option1` field using the `ValidateOption1` function.

2) Define your validators:

```go

func ValidateOption1(value string) error {
    if value == "" {
        return fmt.Errorf("Noooooooooooo!")
    }

    return nil
}

```

The validator *must* return an `error` or `nil`.

3) Set it all up:

```go

func main() {
    // ...

    opts := &Options{
        // ...
    }

    fns := map[string]interface{}{
        "ValidateOption1": ValidateOption1,
    }

    vers := &semver.SemVer{1, 2, 3, "herpderp"}
    conf := config.Init("App Name", vers, opts, fns)
    conf.Parse()

    // ...
}

```

Options will be parsed during `init`. Any validation or JSON errors will result in the program exiting with error information dumped to stdout.

It is worth noting that there are three special structure tags:

* `config_hide`: Field is hidden when the config is dumped to string,

* `config_obscure`: Field is obscured with asterisks when dumped,

* `config_validator`: The validation function for the field.

func Init

func Init(
	name string,
	version *semver.SemVer,
	data any,
	fns ValidatorsMap,
	required bool,
) Config

Init a new configuration instance.

func NewConfig

func NewConfig(
	name string,
	version *semver.SemVer,
	data any,
	fns ValidatorsMap,
	required bool,
) Config

Create a new configuration instance.

func NewDefaultConfig

func NewDefaultConfig(required bool) Config

Create a new empty `Config` instance.

type ValidatorsMap

type ValidatorsMap map[string]interface{}