env

Documentation

Overview

Package env implements pulling environment variables into a struct.

This file is based on code from caarlos0/env, available at github.com/caarlos0/env

Copyright (c) 2015-2024 Carlos Alexandro Becker Licensed under the MIT License. See the LICENSE file in the original project for details.

Modifications made by Kenzo Spaulding, 2024

Index

• Variables
• func Must[T any](t T, err error) T
• func Parse(v interface{}) error
• func ParseAs[T any]() (T, error)
• func ParseAsWithOptions[T any](opts Options) (T, error)
• func ParseWithOptions(v interface{}, opts Options) error
• func ToMap(env []string) map[string]string
• type FieldParams
  • func GetFieldParams(v interface{}) ([]FieldParams, error)
  • func GetFieldParamsWithOptions(v interface{}, opts Options) ([]FieldParams, error)
• type OnSetFn
• type Options
• type ParserFunc

Variables

var (
	ErrParseValue           = errors.New("unable to parse")
	ErrStructPtr            = errors.New("not struct pointer error")
	ErrNoSupportedTagOption = errors.New("tag option not supported")
	ErrVarIsNotSet          = errors.New("required environment variable is not set")
	ErrEmptyVar             = errors.New("environment variable should not be empty")
	ErrLoadFileContent      = errors.New("could not load content of file from variable")
	ErrNoParser             = errors.New("no parser found")
)

Functions

func Must

func Must[T any](t T, err error) T

Must panic is if err is not nil, and returns t otherwise.

func Parse

func Parse(v interface{}) error

Parse parses a struct containing `env` tags and loads its values from environment variables.

func ParseAs

func ParseAs[T any]() (T, error)

ParseAs parses the given struct type containing `env` tags and loads its values from environment variables.

func ParseAsWithOptions

func ParseAsWithOptions[T any](opts Options) (T, error)

ParseWithOptions parses the given struct type containing `env` tags and loads its values from environment variables.

func ParseWithOptions

func ParseWithOptions(v interface{}, opts Options) error

ParseWithOptions parses a struct containing `env` tags and loads its values from environment variables.

func ToMap

func ToMap(env []string) map[string]string

ToMap Converts list of env vars as provided by os.Environ() to map you can use as Options.Environment field

Types

type FieldParams

type FieldParams struct {
	OwnKey          string
	Key             string
	DefaultValue    string
	HasDefaultValue bool
	Required        bool
	LoadFile        bool
	Unset           bool
	NotEmpty        bool
	Expand          bool
	Init            bool
	Ignored         bool
}

FieldParams contains information about parsed field tags.

func GetFieldParams

func GetFieldParams(v interface{}) ([]FieldParams, error)

GetFieldParams parses a struct containing `env` tags and returns information about tags it found.

func GetFieldParamsWithOptions

func GetFieldParamsWithOptions(v interface{}, opts Options) ([]FieldParams, error)

GetFieldParamsWithOptions parses a struct containing `env` tags and returns information about tags it found.

type OnSetFn

type OnSetFn func(tag string, value interface{}, isDefault bool)

OnSetFn is a hook that can be run when a value is set.

type Options

type Options struct {
	// Environment keys and values that will be accessible for the service.
	Environment map[string]string

	// TagName specifies another tag name to use rather than the default 'env'.
	TagName string

	// PrefixTagName specifies another prefix tag name to use rather than the default 'envPrefix'.
	PrefixTagName string

	// DefaultValueTagName specifies another default tag name to use rather than the default 'envDefault'.
	DefaultValueTagName string

	// RequiredIfNoDef automatically sets all fields as required if they do not
	// declare 'envDefault'.
	RequiredIfNoDef bool

	// OnSet allows to run a function when a value is set.
	OnSet OnSetFn

	// Prefix define a prefix for every key.
	Prefix string

	// UseFieldNameByDefault defines whether or not `env` should use the field
	// name by default if the `env` key is missing.
	// Note that the field name will be "converted" to conform with environment
	// variable names conventions.
	UseFieldNameByDefault bool

	// Custom parse functions for different types.
	FuncMap map[reflect.Type]ParserFunc
	// contains filtered or unexported fields
}

Options for the parser.

type ParserFunc

type ParserFunc func(v string) (interface{}, error)

ParserFunc defines the signature of a function that can be used within `Options`' `FuncMap`.