goconfig

README

goconfig

Simple configuration file parser for property and yaml files. Allows for fields in config files to be environment variables with default values.

Install

go get github.com/MartinSimango/goconfig

Example

Below is an example config yaml file that goconfig can parse:

Config File (app.yaml)

# app.yaml

port: ${SERVICE_PORT,8000}
service-name: service
db: 
  host: ${DB_HOST, 127.0.0.1}
  port: ${DB_PORT,8890}

The format of a config value is:

configValue: ${ENVIRONMENT_VARIABLE,default_value}  
# OR 
configValue: ${ENVIRONMENT_VARIABLE} 
# OR 
configValue: value

Below is an example of the code that parse the config file and stores the config within a struct.

Example Program - Loading program config from yaml file (main.go)

package main

import (
	"fmt"

	"github.com/MartinSimango/goconfig"
)

type YamlServiceConfiguration struct {
	Port        int    `yaml:"port"`
	ServiceName string `yaml:"service-name"`
	DB          struct {
		Host string `yaml:"host"`
		Port int    `yaml:"port"`
	} `yaml:"db"`
}

func main() {

	fileConfig := goconfig.YamlFileConfiguration("app.yaml", &YamlServiceConfiguration{})
	fileParser := goconfig.NewConfigFileParser(fileConfig)

	config, err := fileParser.ParseConfig()

	if err != nil {
		fmt.Println(err)
	} else {
		yamlConfig := config.(*YamlServiceConfiguration) // cast if needed

		fmt.Printf("%+v", yamlConfig)
	}
}

Notes

Currently the only supported primitive types in config structs are:

• string
• bool
• int
• int8
• int16
• int32
• int64
• float32
• float64

I plan on adding other types very shortly.

Contributing

• Fork the repo on GitHub
• Clone the project to your own machine
• Create a branch with your modifications git checkout -b feature/new-feature.
• Then commit your changes git commit -m 'Added new feature
• Make a push to your branch git push origin feature/new-feature.
• Submit a Pull Request so that I can review your changes

Documentation

Index

• func FieldErrorsToString(fieldErrors []FieldError) string
• func FileFormatToString(fileFormat FileFormat) string
• type ConfigError
• type ConfigFileParser
• type ConfigFileParserImpl
  • func NewConfigFileParser(fileConfiguration *FileConfiguration) *ConfigFileParserImpl
  • func (cf *ConfigFileParserImpl) ParseConfig() (interface{}, error)
• type Error
• type FieldError
  • func AppendFieldError(configFieldErrors []FieldError, fieldError *FieldError) []FieldError
  • func ToFieldError(field string, err error) *FieldError
  • func (cfe *FieldError) Error() string
• type FileConfigError
  • func (fce *FileConfigError) Error() string
• type FileConfiguration
  • func JsonFileConfiguration(configFile string, config interface{}) *FileConfiguration
  • func NewFileConfiguration(fileName string, fileFormat FileFormat, fileInputConfiguration interface{}, ...) *FileConfiguration
  • func PropertyFileConfiguration(configFile string, config interface{}) *FileConfiguration
  • func YamlFileConfiguration(configFile string, config interface{}) *FileConfiguration
• type FileFormat

Functions

func FieldErrorsToString

func FieldErrorsToString(fieldErrors []FieldError) string

FieldErrorsToString coverts an array of field arrays into a string

func FileFormatToString

func FileFormatToString(fileFormat FileFormat) string

Types

type ConfigError

type ConfigError interface {
	Error
}

type ConfigFileParser

type ConfigFileParser interface {
	ParseConfig() (interface{}, error)
}

ConfigFileParser parses the config file

type ConfigFileParserImpl

type ConfigFileParserImpl struct {
	FileConfiguration *FileConfiguration
}

func NewConfigFileParser

func NewConfigFileParser(fileConfiguration *FileConfiguration) *ConfigFileParserImpl

DefaulltConfigFileParser is a constructor

func (*ConfigFileParserImpl) ParseConfig

func (cf *ConfigFileParserImpl) ParseConfig() (interface{}, error)

ParseConfig parses the file configured the FileConfiguration struct variable's FileName parameter.

type Error

type Error interface {
	error
}

type FieldError

type FieldError struct {
	Field        string
	ErrorMessage string
}

func AppendFieldError

func AppendFieldError(configFieldErrors []FieldError, fieldError *FieldError) []FieldError

AppendFieldError appends fieldError to the configFieldErrors are and returns the resulting slice.

func ToFieldError

func ToFieldError(field string, err error) *FieldError

ToFieldError converts err into a field error

func (*FieldError) Error

func (cfe *FieldError) Error() string

type FileConfigError

type FileConfigError struct {
	ConfigFile  string
	FileFormat  FileFormat
	FieldErrors []FieldError
}

func (*FileConfigError) Error

func (fce *FileConfigError) Error() string

type FileConfiguration

type FileConfiguration struct {
	FileName               string
	FileFormat             FileFormat
	FileInputConfiguration interface{}
	EnvironmentLoader      goenvloader.EnvironmentLoader
}

func JsonFileConfiguration

func JsonFileConfiguration(configFile string, config interface{}) *FileConfiguration

func NewFileConfiguration

func NewFileConfiguration(fileName string,
	fileFormat FileFormat,
	fileInputConfiguration interface{},
	environmentLoader goenvloader.EnvironmentLoader) *FileConfiguration

func PropertyFileConfiguration

func PropertyFileConfiguration(configFile string, config interface{}) *FileConfiguration

func YamlFileConfiguration

func YamlFileConfiguration(configFile string, config interface{}) *FileConfiguration

type FileFormat

type FileFormat int

const (
	YAML FileFormat = iota
	JSON
	PROPERTY
)