config2env

config2env is a simple CLI tool that converts your JSON and YAML configuration files to Unix environment variables.

Note: For now, only JSON and YAML files are supported. TOML and HCL formats also will be supported.

Install

go get github.com/tahasevim/config2env/cmd/config2env

Usage

JSON Types

YAML Types

Example with Docker

Docker client provides --env-file option to read a file of environment variables so that we can avoid specifiying each environment variable by using -e flag.

Let's assume that we got an config.env with the contents of:

SERVICE_A_ADDR=localhost
SERVICE_A_PORT=8080
SERVICE_B_ADDR=localhost
SERVICE_B_PORT=9090

and assume that we have a simple program main.go as below:

package main

import (
	"fmt"
	"os"
)

func main() {
	for _, e := range os.Environ() {
		fmt.Println(e)
	}
}

Then you can build an image as below:

$ docker build -t testenv -f- . <<EOF
FROM golang:latest
COPY main.go .
CMD ["go", "run", "main.go"]
EOF

Finally we can run built docker image:

$ docker run --env-file config.env testenv

You will see results printed to the screen which will be similar to:

PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=febf40d13596
SERVICE_A_ADDR=localhost
SERVICE_A_PORT=8080
SERVICE_B_ADDR=localhost
SERVICE_B_PORT=9090
GOLANG_VERSION=1.13
GOPATH=/go
HOME=/root

Note that other environment variables come from other image layers that our image is built on top of those layers.

You can also pass these .env files using docker-compose with env_file option. For more detailed information see the official docs