build images for projects that use externpro

• Getting started with docker
  • install and configure docker
  • verify docker installation and configuration
  • short docker tutorial
  • useful docker commands
• buildpro packages
• Using buildpro

Install Docker Engine https://docs.docker.com/engine/install/

If you don't want to preface the docker command with sudo, create a Unix group called docker and add users to it. See "Post-installation steps for Linux" https://docs.docker.com/engine/install/linux-postinstall/ for details and warnings.

(all examples below now assume you have configured your system to run docker without sudo)

$ docker run hello-world

you should see a "Hello from Docker!" message with additional details

image vs container https://stackify.com/docker-image-vs-container-everything-you-need-to-know/

• in other virtual machine environments, images would be called something like "snapshots"
• Docker images can't ever change -- once you've made one, you can delete it, but you can't modify it
• if you need a new version of the snapshot, you create an entirely new image
• if a Docker image is a digital photograph, a Docker container is like a printout of that photograph
• a container is an "instance" of the image
• each Docker container runs separately, and you can modify the container while it's running

$ docker image ls
REPOSITORY    TAG      IMAGE ID       CREATED         SIZE
hello-world   latest   bf756fb1ae65   10 months ago   13.3kB

$ docker container ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED         STATUS                     PORTS   NAMES
feaadc8cc2b1   hello-world   "/hello"   2 minutes ago   Exited (0) 2 minutes ago           romantic_torvalds

shorter versions of these commands

• docker images instead of docker image ls
• docker ps -a instead of docker container ps -a
• a lot of docker commands assume "container"
  • docker run is short for docker container run
  • docker rm is short for docker container rm

the commands docker image and docker container will display commands for managing images and containers

if docker image rm hello-world is attempted, there is an error that a container is using its referenced image, so first remove the container, using it's randomly assigned name "romantic_torvalds" or the container ID

$ docker rm romantic_torvalds
$ docker image rm hello-world

$ docker images
$ docker ps -a
$ docker [stop|restart|start|rm|logs|inspect] <container_name>
$ docker inspect <container_name> | grep -i ipaddress
$ docker exec -it <container_name> bash

• the public buildpro packages are built and published by GitHub Actions
• the public/ghimg.sh script can be ran to develop/build/test local images

To use buildpro images

• add externpro as a submodule to the project wanting to leverage buildpro images, optimally to .devcontainer

  git submodule add https://github.com/externpro/externpro .devcontainer
  

• create symbolic links to the compose.*.[sh|yml] file pair suitable for the project

  ln -s .devcontainer/compose.pro.sh docker-compose.sh
  ln -s .devcontainer/compose.bld.yml docker-compose.yml
  

• ./docker-compose.sh -h to display a help message showing usage and options

• there are various .devcontainer/compose.*.sh scripts that use different buildpro docker images (link to a different one to use a different buildpro image)

  script	buildpro image
  compose.pro.sh	rocky-pro
  compose.bld.sh	rocky-mdv
  compose.ci.sh	rocky-ci
  compose.gpu.sh	rocky-pin or rocky-pdv

• this graph shows the image dependencies and what the various buildpro images have been used for