dfpp - Dockerfile preprocessor

 $ dfpp Dockerfile.pre > Dockerfile

 # without installing run via docker:
 $ docker run --rm -i -v $(pwd):/root:ro coryb/dfpp Dockerfile.pre > Dockerfile

 # or alias dfpp to docker call
 $ alias dfpp='docker run --rm -i -v $(pwd):/root:ro coryb/dfpp'
 $ dfpp Dockerfile.pre > Dockerfile

 # Dockerfile Syntax:
 INCLUDE ./Dockerfile.inc
 INCLUDE http://path/to/Dockerfile.inc
 INCLUDE ./Dockerfile.inc http://path/to/Dockerfile.inc

 INCLUDE MERGE a.inc b.inc

 # include only RUN instructions
 INCLUDE RUN a.inc b.inc

 # include only RUN and ENV instructions
 INCLUDE RUN ENV a.inc b.inc

 # include only RUN and ENV instructions but merge them
 INCLUDE MERGE RUN ENV a.inc b.inc

 # exclude FROM instructions
 INCLUDE -FROM a.inc b.inc

dfpp was written to allow simple pre-processing of Dockerfiles to add capabilities currently unsupported by docker build.

The INCLUDE instruction is primarily useful to make Dockerfiles composible if you have wide variation in images being produced but you dont want to copy & paste common instructions. For example, if you are using docker for build isolation where you have some projects that are c++ and some that are java. Typically you would create a specific cpp-build image with all the c++ build dependencies and a java-build image with all the java build dependencies. Then you find yourself needing to build something that requires both c++ AND java, so you create a cpp-java-build image . Now you are maintaining the c++ build deps in the cpp-build and cpp-java-build image. INCLUDE allows you to maintain the build deps in a single location and simply reference that single location for both cpp-build and cpp-java-build images.

This will inline a file or uri into the Dockerfile being generated.

When including multiple Dockerfile snippets this will attempt to merge common instructions. Currently only ENV, LABEL and RUN are merged, otherwise multiple instructions will be repeated. RUN instructions are merged with "&&" while other instructions are merged with a space.

Include or Exclude ADD instructions from inlined Dockerfile snippets

Include or Exclude CMD instructions from inlined Dockerfile snippets

Include or Exclude COPY instructions from inlined Dockerfile snippets

Include or Exclude ENTRYPOINT instructions from inlined Dockerfile snippets

Include or Exclude ENV instructions from inlined Dockerfile snippets

Include or Exclude EXPOSE instructions from inlined Dockerfile snippets

Include or Exclude FROM instructions from inlined Dockerfile snippets

Include or Exclude INCLUDE instructions from inlined Dockerfile snippets

Include or Exclude LABEL instructions from inlined Dockerfile snippets

Include or Exclude MAINTAINER instructions from inlined Dockerfile snippets

Include or Exclude ONBUILD instructions from inlined Dockerfile snippets

Include or Exclude RUN instructions from inlined Dockerfile snippets

Include or Exclude USER instructions from inlined Dockerfile snippets

Include or Exclude VOLUME instructions from inlined Dockerfile snippets

Include or Exclude WORKDIR instructions from inlined Dockerfile snippets

2015, Cory Bennett github@corybennett.org

The Source is available at github: https://github.com/coryb/dfpp

Copyright (c) 2015 Netflix Inc. All rights reserved. The copyrights to the contents of this file are licensed under the Apache License, Version 2.0.