Patchwork Docker

Purpose

Allows a Docker build to be easily changed, without having to clone and modify an existing build repository.

Features

All with a single command, the tool can:

• Build images from a different base image.
• Add/override files in the build context.
• Apply patches to the Dockerfile or other files in the build context.
• Define a different Dockerfile.

Use Cases

A few basic use cases (./docker-run.sh can be used instead of patchworkdocker):

• To change a base image from debian:stretch to python:3.7-stretch so as to get the latest version of Python in the image with no hassle:

  patchworkdocker build example:1.0.0 https://github.com/example/docker-example.git \
      --base-image python:3.7-stretch
  

• Add an alternate Dockerfile to a pre-existing context:

  patchworkdocker build example:1.0.0 https://github.com/example/docker-example.git \
      --additional-file Dockerfile:Dockerfile.example \
      --dockerfile Dockerfile.example
  

• Change the URL of a piece of software that gets installed into a Docker image:

  patchworkdocker build example:1.0.0 https://github.com/docker-library/python.git \
      --dockerfile 3.7/stretch/Dockerfile \
      --patch change-install-url.patch:Dockerfile
  

Raspberry Pi users may find this tool particularly useful as, outside the official images, there is often need to change image build in order to get them to work on the non-standard rpi architectures.

Installation

Prerequisites

• Docker
• Python 3.7+ (optional, as can be run entirely from Docker if you don't have Python 3.7)

The tool can be installed directly from GitHub:

pip install git+https://github.com/colin-nolan/patchwork-docker@master#egg=patchworkdocker

Usage

Up-to-date usage information can be seen with:

patchworkdocker --help
patchworkdocker build --help