dol / bash-envtpl

Simple envtpl implementation in bash

bash-envtpl

Simple envtpl implementation in Bash

Details

Inspired by envtpl written in python this repo is basic equivalent in Bash. The main goal is to avoid the dependency of Python and pip within a Docker container. This saves about 50MB container size.

Most of the time a envtpl template file looks like this:

{% for key, value in environment('VAR_PREFIX_') %}{{ key|lower|replace('_','-') }}={{ value }}
{% endfor %}

The rendered template is stored to a file.

The bash function envtpl performs this work.

envtpl ENV_PREFIX TARGET_FILE [KEY_DELIMITER='_'] [KEY_DELIMITER_REPLACEMENT='-'] [VALUE_DELIMITER='=']

Usage

1. Copy/paste file envtpl.sh or bash function envtpl into your entrypoint script
2. Call envtpl function

#!/usr/bin/env bash
# Source envtpl.sh if file was copied
. envtpl.sh
# E.g APP_API_KEY=mykey stores api.key:mykey into /etc/app/production.conf
envtpl APP_ /etc/app/production.conf '_' '.' ':'

Requirements

• Bash 4.0 (Released 2009)