config

README

Config

config is hassle-free config struct setting for golang, setting things like configStruct.StringField to the value of the enviornment variable STRING_FIELD. It wraps the lovely godotenv package, which itself is a go port of the ruby dotenv gem.

License & Copyright

Copyright (C) 2017 Data Together This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, version 3.0.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the LICENSE file for details.

Getting Involved

We would love involvement from more people! If you notice any errors or would like to submit changes, please see our Contributing Guidelines.

We use GitHub issues for tracking bugs and feature requests and Pull Requests (PRs) for submitting changes

Usage

Add config to any golang package with import "github.com/datatogether/config"

Basic use has three steps:

1. declare a struct that defines all your config values (eg: type cfg struct{ ... })
2. (optional) create a file or two that sets enviornement vars.
3. call config.Load(&cfg, "envfilepath")

config will read that env file, setting environment variables for the running process and infer any ENVIRIONMENT_VARIABLE value to it's cfg.EnvironmentVariable counterpart/

config uses a CamelCase -> CAMEL_CASE convention to map values. So a struct field cfg.FieldName will map to an environment variable FIELD_NAME. Types are inferred, with errors returned for invalid env var settings.

Using an env file is optional, calling Load(cfg) is perfectly valid.

config uses the reflect package to infer & set values reflect is a good choice here because setting config happens seldom in the course of a running program, and these days if you're parsing JSON, the reflect package is already included in your binary.

Technical documentation can be built with godoc . or, if your $GOPATH and repo structure is set up correctly, with something like godoc -http=:6060 & followed by browsing to http://localhost:6060/pkg/github.com/datatogether.

Development

Coming soon.

Documentation

Overview

config is hassle-free config struct setting. setting things like configStruct.StringField to the value of the enviornment variable STRING_FIELD. It wraps the lovely godotenv package, which itself is a go port of the ruby dotenv gem.

Basic use has three steps:

1. declare a struct that defines all your config values (eg: type cfg struct{ ... })
2. (optional) create a file or two that sets enviornement vars.
3. call config.Load(&cfg, "envfilepath")

config will read that env file, setting environment variables for the running process and infer any ENVIRIONMENT_VARIABLE value to it's cfg.EnvironmentVariable counterpart/

config uses a CamelCase -> CAMEL_CASE convention to map values. So a struct field cfg.FieldName will map to an environment variable FIELD_NAME. Types are inferred, with errors returned for invalid env var settings.

using an env file is optional, calling Load(cfg) is perfectly valid.

config uses the reflect package to infer & set values reflect is a good choice here because setting config happens seldom in the course of a running program, and these days if you're parsing JSON, the reflect package is already included in your binary

Index

• func EnvVarKey(key string) string
• func Load(dst interface{}, filenames ...string) error
• func Overload(dst interface{}, filenames ...string) error

Functions

func EnvVarKey

func EnvVarKey(key string) string

EnvVarKey takes a CamelCase string and converts it to a CAMEL_CASE string (uppercase snake_case)

func Load

func Load(dst interface{}, filenames ...string) error

Load will read any passed-in env file(s) and load them into ENV for this process, then assign values to the passed in dst struct pointer. Call this function as close as possible to the start of your program (ideally in main) If you call Load without any args it will default to loading .env in the current path You can otherwise tell it which files to load (there can be more than one) like

godotenv.Load("fileone", "filetwo")

It's important to note that it WILL NOT OVERRIDE an env variable that already exists - consider the .env file to set dev vars or sensible defaults

func Overload

func Overload(dst interface{}, filenames ...string) error

Overload will read any passed-in env file(s) and load them into ENV for this process, then assign values to the passed in dst struct pointer. Call this function as close as possible to the start of your program (ideally in main) If you call Overload without any args it will default to loading .env in the current path You can otherwise tell it which files to load (there can be more than one) like

godotenv.Overload("fileone", "filetwo")

It's important to note this WILL OVERRIDE an env variable that already exists - consider the .env file to forcefilly set all vars.