A Go port of Ruby's dotenv library (Loads environment variables from `.env`.)
Latest commit 726cc8b Dec 17, 2016 @joho committed on GitHub Merge pull request #22 from mmilata/dont-swallow-errors
Improve error handling


GoDotEnv wercker status

A Go (golang) port of the Ruby dotenv project (which loads env vars from a .env file)

From the original Library:

Storing configuration in the environment is one of the tenets of a twelve-factor app. Anything that is likely to change between deployment environments–such as resource handles for databases or credentials for external services–should be extracted from the code into environment variables.

But it is not always practical to set environment variables on development machines or continuous integration servers where multiple projects are run. Dotenv load variables from a .env file into ENV when the environment is bootstrapped.

It can be used as a library (for loading in env for your own daemons etc) or as a bin command.

There is test coverage and CI for both linuxish and windows environments, but I make no guarantees about the bin version working on windows.


As a library

go get github.com/joho/godotenv

or if you want to use it as a bin command

go get github.com/joho/godotenv/cmd/godotenv


Add your application configuration to your .env file in the root of your project:


Then in your Go app you can do something like

package main

import (

func main() {
  err := godotenv.Load()
  if err != nil {
    log.Fatal("Error loading .env file")

  s3Bucket := os.Getenv("S3_BUCKET")
  secretKey := os.Getenv("SECRET_KEY")

  // now do something with s3 or whatever

If you're even lazier than that, you can just take advantage of the autoload package which will read in .env on import

import _ "github.com/joho/godotenv/autoload"

While .env in the project root is the default, you don't have to be constrained, both examples below are 100% legit

_ = godotenv.Load("somerandomfile")
_ = godotenv.Load("filenumberone.env", "filenumbertwo.env")

If you want to be really fancy with your env file you can do comments and exports (below is a valid env file)

# I am a comment and that is OK
FOO=BAR # comments at line end are OK too
export BAR=BAZ

Or finally you can do YAML(ish) style

FOO: bar
BAR: baz

as a final aside, if you don't want godotenv munging your env you can just get a map back instead

var myEnv map[string]string
myEnv, err := godotenv.Read()

s3Bucket := myEnv["S3_BUCKET"]

Command Mode

Assuming you've installed the command as above and you've got $GOPATH/bin in your $PATH

godotenv -f /some/path/to/.env some_command with some args

If you don't specify -f it will fall back on the default of loading .env in PWD


Contributions are most welcome! The parser itself is pretty stupidly naive and I wouldn't be surprised if it breaks with edge cases.

code changes without tests will not be accepted

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Added some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request


Linux: wercker status Windows: Build status


The original library dotenv was written by Brandon Keepers, and this port was done by John Barton based off the tests/fixtures in the original library.