Dockerfiles unnecessarily large

[tholiao]

Dockerfiles have too many layers

Problem description:

Dockerfiles are unnecessarily long, i.e. too many layers during build and retain build artifacts

Problem example:

RUN apt-get -y install git make cmake unzip
RUN apt-get -y install libxrandr2 libxinerama-dev libxi6 libxcursor-dev

from rllab/docker/Dockerfile lines 27 and 33

Problem Implication:

unnecessarily large docker images -> harder to run multiple images on same machine

Solution description:

best practices recommend chaining / combining as many commands as possible to remove unnecessary layers

Solution example:

RUN apt-get update && apt-get install -y \
    build-dep glfw \
    libxrandr2 libxinerama-dev libxi6 libxcursor-dev \
 && rm -rf /var/lib/apt/lists/*

Solution source:

Best practices for writing Dockerfiles