Environment variable support for Yaml in Go

Introduction

Yenv allows you to support environment variables in a yaml file from within Go. Yenv takes an marshalled yaml object and applies the values of any system environment variables and returns the unmarshalled object.

Installation

Install

go get github.com/artbegolli/yenv

Import

import "github.com/artbegolli/yenv"

Usage

Yenv will look for any environment variables in yaml values with the format ${ENV_KEY_HERE}

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "github.com/artbegolli/yenv"
)

func main() {

    /* Example Yaml ./myyamlfile.yaml:
        age: 30
        name: John
        job: ${JOB_ENV}
    */
    
    // Set an environment variable
    os.Setenv("JOB_ENV", "software_stuff")
    yaml, _ := ioutil.ReadFile("./myyamlfile.yaml")

    yamlWithEnvApplied, err := yenv.ApplyEnvValues(yaml)
    if err != nil {
        fmt.Printf("err: %v\n", err)
        return
    }
    fmt.Println(string(yamlWithEnvApplied))
    /* Output
        age: 30
        name: John
        job: software_stuff
    */
}

You can also use yenv to unmarshall your yaml with the environment variables replaced. You can pass in your read-in yaml byte array and a struct to unmarshall.

package main

import (
    "fmt"
    "os"
    "github.com/artbegolli/yenv"
)

func main() {

    /* Example Yaml:
        age: 30
        name: John
        job: ${JOB_ENV}
    */
    
    // Set an environment variable
    os.Setenv("JOB_ENV", "software_stuff")
    
    // Unmarshal the YAML back into a Person struct.
    var p Person
    err := yenv.UnmarshallWithEnv(y, &p)
    if err != nil {
        fmt.Printf("err: %v\n", err)
        return
    }
    fmt.Println(p)
    /* Output:
    {John 30 software_stuff}
    */
}