Config loader

Config loader let's you load config from yaml file into your apps config structs based on profile.

For Go v12+

Inspired by Spring Boot profiles.

Install

go get github.com/spacanowski/go-config/loader

How it works

Config loader takes application yaml file (either yaml or yml extension) and maps it into coresponding struct. You could overwrite or define additional params in application-<profile>.yml files where <profile> is any profile name, e.g. application-dev.yml, application-test.yml or any other. Profile flag and files are optional. Profile name arg can be passed by program call param --profile=<profile> or -p=<profile> where <profile> is profile name coresponding to one defined in profile config file.

If struct config value is not deffined in yaml file, then default type value is used. If yaml file has values not deffied in struct, they'll be ignored.

Example usage

See full example or short one below.

Define config struct

type myAppConfig struct {
    appName      string
    accountName  string
    aws          struct {
        accountNumber int
        regions       []string
        clientSqs     map[string]string
        db            struct {
            autoCommit bool
            url        string
            username   string
        }
    }
}

Create application.yml file with common config

appName: 'My app'
accountName: dev-account
aws:
  regions: ['eu-west-1']
  accountNumber: 123123
  clientSqs:
    client1: 'client1-q'
    client2: 'client2-q'
  db:
    autoCommit: true
    url: 'dev.db.url'
    username: db-user

Create optional profile config file application-<profile>.yml, e.g.

application-test.yaml

accountName: test-account
aws:
  regions: ['eu-west-1']
  accountNumber: 321321
  clientSqs:
    client1: 'client1-q'
    client2: 'client2-q'
  db:
    url: 'test.db.url'
    username: test-db-user

application-prod.yml

accountName: prod-account
aws:
  regions: ['eu-west-1', 'eu-central-1']
  accountNumber: 441441
  clientSqs:
    client1: 'client1-q'
    client2: 'client2-q'
    client3: 'client3-q'
  db:
    url: 'prod.db.url'
    username: prod-db-user

Import loader and load config

import (
    configloder github.com/spacanowski/go-config/loader
)

func main() {
    var config myAppConfig
    if err := configloader.Load(&config); err != nil {
        // Handle config load error
    }
    // Use config
}

Run your app without profile (values taken only from application.yml)

go run my-app.go

or with profile app arg, depending on which config profile you want to use (values taken from application.yml and coresponding profile).

go run my-app.go --profile=test or ./my-app -p=test