Install Docker using a Dockerfile

Question

I have a Dockerfile that looks like this:

# Pull base image
FROM  openjdk:8

ENV SCALA_VERSION 2.12.2
ENV SBT_VERSION 0.13.15

# Scala expects this file
RUN touch /usr/lib/jvm/java-8-openjdk-amd64/release

# Install Scala
## Piping curl directly in tar
RUN \
  curl -fsL http://downloads.typesafe.com/scala/$SCALA_VERSION/scala-$SCALA_VERSION.tgz | tar xfz - -C /root/ && \
  echo >> /root/.bashrc && \
  echo 'export PATH=~/scala-$SCALA_VERSION/bin:$PATH' >> /root/.bashrc

# Install sbt
RUN \
  curl -L -o sbt-$SBT_VERSION.deb http://dl.bintray.com/sbt/debian/sbt-$SBT_VERSION.deb && \
  dpkg -i sbt-$SBT_VERSION.deb && \
  rm sbt-$SBT_VERSION.deb && \
  apt-get update && \
  apt-get install sbt && \
  sbt sbtVersion

# Install Docker
RUN \
  # if we have older versions, let's get rid of them first
  apt-get install docker

# Define working directory
WORKDIR /root

What I want to do is, I would like to install Docker into this image and be able to run docker commands form within. How do I start the installed docker instance?

you may want to check this out: https://github.com/jpetazzo/dind/blob/master/Dockerfile — Gabriele Petronella, Jun 28 '17 at 13:28

score 6 · Accepted Answer · edited Feb 08 '21 at 21:43

You can install the docker client binary only and share dockerd with the container and host.

Here is an example Dockerfile:

FROM  openjdk:8

# Install your dependencies
# ...

# Install curl
RUN apt-get update && apt-get install -y \
  curl \
  && rm -rf /var/lib/apt/lists/*

# Install docker client    
ENV DOCKER_CHANNEL stable
ENV DOCKER_VERSION 17.03.1-ce
ENV DOCKER_API_VERSION 1.27
RUN curl -fsSL "https://download.docker.com/linux/static/${DOCKER_CHANNEL}/x86_64/docker-${DOCKER_VERSION}.tgz" \
  | tar -xzC /usr/local/bin --strip=1 docker/docker

Build the image:

$ docker build -t docker-client .

Run a docker container with mounting /var/run/docker.sock, and then you can use docker command in the container:

$ docker run --rm -it -v /var/run/docker.sock:/var/run/docker.sock docker-client /bin/bash
root@c696b78206a8:/# docker version
Client:
 Version:      17.03.1-ce
 API version:  1.27
 Go version:   go1.7.5
 Git commit:   c6d412e
 Built:        Mon Mar 27 16:58:30 2017
 OS/Arch:      linux/amd64

Server:
 Version:      17.05.0-ce
 API version:  1.29 (minimum version 1.12)
 Go version:   go1.7.5
 Git commit:   89658be
 Built:        Thu May  4 21:43:09 2017
 OS/Arch:      linux/amd64
 Experimental: false

Note that mounting the docker.sock means that the container is permitted access to the docker host. Please be aware that there are potential security risks.

Thanks for the reply! The container getting access to the docker host is not a problem because this will be used only to build and run tests. Once this is done, we will not use docker in docker! — joesan, Jul 03 '17 at 10:56

score 3 · Answer 2 · answered Jun 28 '17 at 13:33

I would recommend you that use the official "dind" image (docker in docker): https://hub.docker.com/_/docker/ . However you will need to rewrite your Dockerfile.

FROM docker:dind-stable
# Install your stuff

And, take into account this:

Although running Docker inside Docker is generally not recommended, there are some legitimate use cases, such as development of Docker itself.

Install Docker using a Dockerfile

2 Answers2