Dockerfile-template NPM

dockerfile-template

DEPRECATED -- This module has been deprecated; please use balena-compose instead.

Process dockerfile templates, a format that allows replacing variables in dockerfiles.

Installation

npm install dockerfile-template

Format

The format of a dockerfile template is the same as a Dockerfile, but augmented with variables.

Variables have the format %%VARIABLE_NAME%%, where variable name starts with an uppercase letter, and can contain uppercase letters and underscores.

Variables in comments (lines that start with #) are not processed.

Library

This module exposes a single process method.

It receives a dockerfile template body and key-value pairs and replaces variables in the template.

If the template has variables that cannot be found, it throws an error.

Example:

dockerfileTemplate = require("dockerfile-template");
  
variables = {
    BASE: "debian",
    TAG: "latest"
};
res = dockerfileTemplate.process("FROM %%BASE%%:%%TAG%%", variables);
console.log(res)

Output:

FROM debian:latest

You can read the tests in test folder for more examples.

Command line usage

The module also exposes a script for command line usage, to test templates.

After installing the module locally, the script should be in ./node_modules/.bin/dockerfile-template.

  Usage: dockerfile-template [options]

  Options:

    -h, --help                     output usage information
    -V, --version                  output the version number
    -f, --filename <templatefile>  template file to process (default: Dockerfile.template)
    -d, --define [VARIABLE=value]  replace variable with value (repeatable option)