env-replace

A simple program to process a file with an environment file to replace the variables inline. Outputs to standard output to allow easy piping to other commands.

Motivation

While beginning to move from Docker Compose centered application deploys to Kubernetes deployment centered ones, it became frustrating that environment variables did not seem as easy to utilize anymore. The process to use environment variables with deployment files felt cumbersome (at least from how I tried to do it) and I did not find any solution that fit what I was trying to do, so here we are.

Installation

wget -q -O - https://raw.githubusercontent.com/mzrimsek/env-replace/main/install.sh | bash

Usage

Prerequisites:

1. The file you want to replace environment variables in your PWD
2. An .env file with the values to replace in your PWD

env-replace <file_name>

You don't declare the .env file. It's assumed to exist and must be called ".env"

Example file to have values replaced

apiVersion: v1
kind: Service
metadata:
  name: ${SERVICE_NAME}
spec:
  ports:
    - protocol: TCP
      port: ${SERVICE_PORT}

Example .env file

SERVICE_NAME=test-service
SERVICE_PORT=8080