Example:

#��Stage��1:��Load��the��project��on��an��empty��image,��in��this��case��this��is��a��development��image��(should��change��to��use��a��minimal��image)

FROM��basmalltalk/pharo:7.0-image��AS��loader

COPY��load-project.st��./

RUN��pharo��Pharo.image��load-project.st��--save��--quit

#��Stage��2:��Copy��the��resulting��Pharo.image��with��our��project��loaded

#��into��a��new��docker��image��with��just��the��vm

#��start��in��a��new��stage��to��keep��docker��image��minimal

FROM��basmalltalk/pharo:7.0

USER��root

WORKDIR��/opt/app

COPY��start.sh��.

COPY��--from=loader��/opt/pharo/Pharo.image��./

COPY��--from=loader��/opt/pharo/Pharo.changes��./

COPY��--from=loader��/opt/pharo/Pharo*.sources��./

RUN��mkdir��logs��\

����&&��chmod��a+x��start.sh��\

����&&��chown��--recursive��pharo:pharo��/opt/app

USER��pharo

EXPOSE��8080

CMD��["./start.sh"]

The resulting image size is ~80mb including image, changes & sources

Reference: https://docs.docker.com/develop/develop-images/multistage-build/

As a side note, the final image size is not what really matters, if you have 20 different images all starting from the same base image (eg ubuntu:18.04) the base layer is shared among all images so the network / disk usage is less than the total size of the image.

It's important to keep the docker image thin, but also to keep layers at a minimum and not adding / removing stuff during the build, because those are stored in the middle layers (multi stage helps to remove that).

Cheers.

On Tue, 15 Oct 2019 at 20:00, Hern��n Morales Durand <hernan.morales@gmail.com> wrote:

El lun., 14 oct. 2019 a las 5:23, Pierce Ng (<pierce@samadhiweb.com>) escribi��:

On Mon, Oct 14, 2019 at 04:07:49AM -0300, Hern��n Morales Durand wrote:
> Because I am lazy and want to avoid searching through all DockerHub
> repository pages... Do you know a Dockerfile to generate the smallest
> possible docker image for Pharo?
> Anyone could make it work Pharo on Alpine since it uses different libc?

Hi Hern��n,

Please see following links:

- https://github.com/pharo-contributions/Docker-Alpine
- https://hub.docker.com/r/pierceng/pharovm-alpine
- https://hub.docker.com/r/pierceng/pharo7-alpine
- https://www.samadhiweb.com/blog/2019.07.20.alpine.pharo.minimal.html
- https://www.samadhiweb.com/blog/2019.08.11.minimizing.pharo.html

Nice! It works with latest minimal 7.0.4 too.

BTW you used .sources whith seem to be for Pharo 7 (Pharo7.0-32bit-0903ade.sources), but when I tried with latest stable minimal and for some reason requires the V60 sources:

$ docker run --rm --ulimit rtprio=2 pharo7_docker_alpine printVersion
Pharo cannot locate the sources file named /pkg/image/PharoV60.sources.

��

I found also another approach using rtprio=2:2 suggested from https://github.com/ba-st/docker-pharo/blob/master/docs/rtprio.md (soft:hard ulimits).

The Alpine-based VM can be made smaller by removing unused/irrelevant
modules.

Image-wise, currently I am using Pharo 7 minimal, which is just under
30MB, and that forms the lower bound of the Pharo image size.

The built image here is aprox. 99 Mbytes

��

REPOSITORY �� �� �� �� �� �� �� TAG �� �� �� �� �� �� �� �� IMAGE ID �� �� �� �� �� ��CREATED �� �� �� �� �� �� SIZE
pharo7_docker_alpine �� �� latest �� �� �� �� �� �� ��595b9ece2625 �� �� �� ��3 hours ago �� �� �� �� 99.4MB

but I think you didn't sumed the .sources.

��

However there is also the Pharo Candle effort that aims to make really
small images, which I hope to try out soon.

> I am also interested in which stage you use to install packages into the
> image, and why? Do you copy the contained image into docker already built?

For Pharo, I start with the regular or minimal image, then load my
packages.

For Docker, I first build a container image for the VM only. Using that
I build a new container image from the Pharo image and other required
files.

Thank you for sharing Pierce.

Hern��n

��