config

README

config

Yet another golang configuration library.

Why?

I wanted to load environment variables and YAML file to my configuration struct that's it.

Feature

• Load configuration from environment variables (using caarlos0/env)
• Optionally load configuration from YAML file (using go-yaml/yaml)

Installation

Go version 1.14+

go get github.com/pk60/config

Example

package main

import (
    "log"

    "github.com/pk60/config"
)

type MyConfig struct {
    Port int `yaml:"port" env:"PORT" envDefault:"3000"`
}

func main()  {
    c := &MyConfig{}
    if err := config.Load(c, config.WithFilename("./config.yml")); err != nil {
        log.Fatalf("failed to load config: %v", err)
    }    
}

Documentation

Please see: pkg.go.dev

License

The Apache 2.0 Licence. Please see License file for more information.

Documentation

Overview

Package config read configuration from environment variables, optionally from YAML file.

Index

• func Load(v interface{}, opts ...Option) error
• type Option
  • func WithFilename(filename string) Option

Examples

• Load
• Load (ParseEnvError)
• Load (ParseYAMLError)
• Load (ReadYAMLError)

Functions

func Load

func Load(v interface{}, opts ...Option) error

Load v with data from environment variables or YAML file (if defined).

Example

package main

import (
	"fmt"
	"os"

	"github.com/pk60/config"
)

func main() {
	_ = os.Setenv("KEY_2", "from env")
	defer os.Unsetenv("KEY_2")

	type conf struct {
		Val  string
		Key1 string
		Key2 string `env:"KEY_2"`
		Key3 string `envDefault:"default value"`
	}

	c := &conf{
		Val: "value",
	}

	_ = config.Load(c, config.WithFilename("./testdata/valid.yml"))
	fmt.Printf("%#v", c)
}

Output:

&config_test.conf{Val:"value from yaml", Key1:"yaml value 1", Key2:"from env", Key3:"default value"}

Example (ParseEnvError)

package main

import (
	"fmt"
	"os"

	"github.com/pk60/config"
)

func main() {
	_ = os.Setenv("INVALID_DATA", "{1+2+3}")
	defer os.Unsetenv("INVALID_DATA")

	type conf struct {
		InvalidData *[]string `env:"INVALID_DATA"`
	}

	c := &conf{}

	err := config.Load(c)
	fmt.Printf("%v", err)
}

Output:

failed to parse environment variables: env: no parser found for field "InvalidData" of type "*[]string"

Example (ParseYAMLError)

package main

import (
	"fmt"

	"github.com/pk60/config"
)

func main() {
	type conf struct{}
	c := &conf{}

	err := config.Load(c, config.WithFilename("./testdata/invalid.yml"))
	fmt.Print(err.Error())
}

Output:

failed to unmarshal YAML file: ./testdata/invalid.yml: yaml: line 2: mapping values are not allowed in this context

Example (ReadYAMLError)

package main

import (
	"fmt"

	"github.com/pk60/config"
)

func main() {
	type conf struct{}
	c := &conf{}

	err := config.Load(c, config.WithFilename("./non_existing_config.yml"))
	fmt.Print(err.Error())
}

Output:

failed to read YAML file: open ./non_existing_config.yml: no such file or directory

Types

type Option

type Option func(*option)

Option config option.

func WithFilename

func WithFilename(filename string) Option

WithFilename assign YAML filename to load.