docker_challenge_hello_world

This is a repository with the source code for a tiny docker image that prints "Docker Hello World!" assembled for ARM. So far the image strips down to 169 Bytes :)

HypriotOS/armv6: pirate@hrrr in ~
$ docker run mpod/docker_challenge_hello_world:armhf
Hello Docker World!
HypriotOS/armv6: pirate@hrrr in ~
$ docker images mpod/docker_challenge_hello_world
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
hello_arm           armhf               8b612212faf3        7 hours ago         169 B

Building

This image has to be built in two steps. First we need to assemble the .asm file to a working binary for ARM with the fasmarm assembler. Unfortunately, this assembler does not run on ARM so we have to do assemble the code on a x86 machine. Once we have the binary built we can copy it over to an ARM machine and build the Docker image there.

Step 1: Build the ARM binary

So log in to a x86 machine and install fasmarm:

root@my-x86 in ~
$ mkdir fasmarm && \
cd fasmarm && \
wget https://arm.flatassembler.net/FASMARM_full.ZIP && \
unzip FASMARM_full.ZIP

Then build your ARM binary with:

root@my-x86 in ~
$ fasmarm hello_arm.asm ~/hello_arm

Step 2: Build the docker image

You have to copy the ARM binary built in Step 1 to an ARM machine and build the docker image there:

HypriotOS/armv6: pirate@hrrr in ~
$ docker build -t hello_arm -f Dockerfile.armhf .

And finally run it :

HypriotOS/armv6: pirate@hrrr in ~
$ docker run hello_arm
Hello Docker World!