General info

This repository contains all dockerfiles useful to build the docker images employed both for development purposes and for deploying applications.

Docker images structure

Our docker images are included inside the folder dockerfile_images, with the following structure:

master
     |_ docker-deployment-images
                                |_ basic
                                        |_ superbuild
                                        |_ ubuntu:focal
                                        ...
                                |_ demos
                                        |_ blender
                                        |_ funny-things
                                        ...

where

• basic: contains images mostly used as base for more complex images
• demos: contains more complex images related to specific applications

⚠️ Important note: the name of the image folder is important, as our building pipeline uses it to tag the image. Thus it must be lower case, as docker does not support upper case in the image name.

Each folder typically includes:

• a Dockerfile used respectively to build a sources image. The sources is an image used for development, where we keep the project repositories
• a Dockerfile4Production (optional), used to build a binaries image. The binaries is an image built starting from sources, but only copying required libraries, binaries etc. from it and thus lighter than the sources.
• a conf_build.ini, including the arguments to build the image.
• an entrypoint.sh (optional), which usually includes definition of the environment. This file is typically copied inside the image (e.g. see here) and then executed when the container is started (e.g. see here).

The conf build file

The conf_build is structured as follows:

[sources]
START_IMG=ubuntu:focal
$(cat DATE_TAG)
release={{steps.get_version.outputs.VERSION}}
sbtag={{matrix.tag}}

[binaries]
SOURCE_IMG={{env.DEFAULT_USER}}/{{matrix.apps}}:{{steps.get_version.outputs.VERSION}}{{steps.get_version.outputs.TAG}}_sources
START_IMG=ubuntu:focal

[tag]
{{matrix.apps}}:{{steps.get_version.outputs.VERSION}}{{steps.get_version.outputs.TAG}}

[superbuild]

[children]
grasp-the-ball
open-face
supervise-calib
superbuild-google
funny-things
superbuild-icubtest

[demos]
yarpBasicDeploy
robotBaseStartup

⚠️ Important note: for custom images, the conf build file keeps the same structure, but some sections / placeholders are missing. In particular, the following is an example of a conf build looks like:

[sources]
START_IMG=ubuntu:focal
$(cat DATE_TAG)

[binaries]
SOURCE_IMG={{env.DEFAULT_USER}}/{{matrix.apps}}:{{steps.get_version.outputs.VERSION}}_sources
START_IMG=ubuntu:focal

[tag]
{{matrix.apps}}:{{steps.get_version.outputs.VERSION}}

[children]
grasp-the-ball-gazebo

The file contains the following sections:

[tag] (required)

This indicates the --tag argument for the docker build and docker push instructions. It does not include the _sources or _binaries tag.

This section must always be:

• {{matrix.apps}}:{{steps.get_version.outputs.VERSION}}{{steps.get_version.outputs.TAG}} for both images based on robotology-superbuild and custom images.

In particular:

• the tag does not contain any data regarding the owner of the image, since that piece of information is added using environmental variables during the step contained in the Workflow file depending on where the image should be pushed (specifically this is done because at this time two different images container are maintaned, i.e. GitHub Container Registry and DockerHub);
• the parameters defined in curly brackets are placeholders for variables filled by the onCodeChanges GA action and replaced by the GA action itself. More specifically:
  • {{matrix.apps}}: the corresponding variable is filled here with the name of the image to be built (i.e. the folder name). We then replace the placeholder with the actual value here;
  • {{steps.get_version.outputs.VERSION}}: the corresponding variable is filled here with the last release of code. We then replace the placeholder with the actual value here;
  • {{steps.get_version.outputs.TAG}}: the corresponding variable is filled here with the project tag (e.g. stable, unstable or empty)

Note: check this for more details on the image naming convention.

[sources] (optional)

This indicates that the image will build a _sources image. This should not be included if a Dockerfile is not provided. Beneath this tag is a list of the arguments to be used when running the docker build instruction.

This section must always be as follows:

• START_IMG=<image_name> where <image_name> bust be replaced with the name of the image used as a base to build the current one
• $(cat DATE_TAG) is used to set the date of building

If you also need to recompile robotology-superbuild, the following additional parameters are also required:

• release={{steps.get_version.outputs.VERSION}} is the last release of code and is replaced with the same logic described above
• sbtag={{matrix.tag}} is the superbuild project tag and is replaced with the same logic described above (only for images based on robotology-superbuild)

[binaries] (optional)

This indicates that the image will build a _binaries image. This should not be included if a Dockerfile4Production is not provided. Beneath this tag is a list of arguments to be used when running the docker build instruction.

This section must always be as follows:

• START_IMG=<image_name> has to include the name of the image we use as a base to build the current one;
• SOURCE_IMG=<source_image_name> is the sources image we use to start build the binaries image. This must be the value specified below the binaries tag section followed by _sources.

[superbuild] (optional)

This indicates that this image compiles robotology-superbuild in its Dockerfile. This allows the github action to correctly tag the image with the superbuild release/master version. This tag should not be included for custom images.

[children] (optional)

This indicates that some images will depend on this image. Beneath this tag is a list of the images that should be rebuilt when changes are done to this image.

[demos] (optional)

This indicates that some demos will depend on this image. Beneath this tag is a list of demos that will be tested when changes are done to this image.