templenv

README

templenv

Install

go get github.com/MarioCarrion/templenv

What is it?

templenv is a command line program for generating output from environment variables by using Go templates, a key piece in the Docker Full Development Workflow. os.StdOut is used for the writer when executing the template.

Templates

templenv uses text/template for generating the final file. Please review the official documentation for learning how to write those templates.

Supported Functions

getEnv

getEnv is a function for accessing environment variables from within templenv. For example, assuming you have a template snowman.tmpl with the following content:

My name is {{ getEnv "USER" }} and I like warm hugs!

and your current username is mario, by using templenv snowman.tmpl the following output will be generated:

My name is mario and I like warm hugs!

loadEnvFilename

loadEnvFilename is a function for reading a file containing environment variables that then parses/converts them into what could look like Docker Compose environment variables.

For example, assuming you have two files, the first one a template docker-compose.tmpl with the following content:

version: '2'
services:
  web:
    image: mariocarrion/templenv:latest
    command: /templenv
    environment:
{{ loadEnvFilename "      " "env.compose" }}

and the second one env.compose with the following content:

# Production env variables
HELLO=world!

The following output will be generated:

version: '2'
services:
  web:
    image: mariocarrion/templenv:latest
    command: /templenv
    environment:
      HELLO: world!

Docker

You can use the included Dockerfile for building your own image, or if you prefer a smaller one you can use the Dockerfile.static, see DockerHub as well.