ONLC Docker Fundamentals Certificate and Synopsis

The certificate of completion and training synopsis for the Docker Fundamentals course taken on May 28-30, 2024 in Boise, ID .

Certificate

Synopsis of ONLC Docker Fundamentals

Getting started with Docker

• Docker is a containerization platform that bundles apps with their dependencies, saving resources over virtual machines.
• Docker engine integrates containers with the host OS.
• Install Docker engine CLI or Docker Desktop.
• Enable virtualization/Hyper-V if not already enabled.

Managing Docker containers

• Host/Repository side:
  • docker pull - download an image.
  • docker push - upload changes to a repository.
• Client Side:
  • docker run - start a container.
  • docker start/stop - manage container state.
  • docker commit - save changes to a new image.

Building images

• Use Dockerfile to manage configurations.
• Key instructions: FROM, MAINTAINER, COPY, ADD, ENV, USER, WORKDIR, VOLUME, EXPOSE, RUN, CMD, ENTRYPOINT, ONBUILD.
• Use .dockerignore to exclude files from the build.

Publishing images

• Set up a Docker Hub account.

• Create Docker image on the local machine using:

• Docker commit sub command.

• Using docker build sub command with a custom Dockerfile.

• Using docker login to login into to docker via command line.

• Push the created docker image to docker hub using docker push

• Delete the image added to Docker Hub using docker web UI.

Running your private Docker infrastructure

• Running a basic self-hosted infrastructure using old docker registry docs archived here by the course instructor here

• Also mentioned JFrog Artifactory, Shipyard as non-free options.

Networking

• Types :

• Bridge – default windows use NAT to the host.

• None – loopback only

• Host - shares host system Ip and ports.

• Ports need to be exposed to access services running in container.

• Bind using -p option with the “docker run” command

• Using the EXPOSE instruction inside the Dockerfile and the run -P (allows internal port exposed to be auto assigned to available random port on host

• Run docker port <container id> to see ports.

Volumes

• Stateful – Needs database / persistent storage to stay in sync with data.

• Stateless – retains no persistent data, docker default.

• Docker volumes – shared folder / filesystem that can be shared among components.

• Named Volumes are created named and added to running container.

• Anonymous volumes automatically created when running docker container run with –mount -v pr –volume

• Things written to volumes will not persist back to the original image pulled.

• Files and folders from host can be shared to the container at run time using docker run -V option.

• Stuff that needs to persist in the image should be committed using docker commit

Orchestrating containers

• Using docker-compose and how to install it

Testing with Docker-CI/CD-Jenkins

• We deployed Jenkins into a container, but this could really be used to once getting the green light in Jenkins to and a processing step to push a container-to-container repo in Jfrog etc.

Debugging containers

• Process level isolation for Docker containers.

• Containers can’t see the host’s process.

• Docker host has complete view of all child process spun up by the docker engine.

• Docker ps, top, stats, exec, logs

Securing Docker containers

• Don’t run as root, use USER option in Dockerfile.

• Use docker Scout and other tools built into docker to evaluate any security risks found in the image before using.

Swarm

• A swarm consists of multiple Docker hosts which run in Swarm mode and act as managers, to manage membership and delegation, and workers, which run swarm services.

• Odd number of managers works best when managing workers.

• We went through a basic swarm example using Play with Docker (play-with-docker.com)

Feedback:

The instructor, Engy Fouda, provided excellent training with a small class size. The hands-on approach and real-time feedback were beneficial. The only downside was the outdated screens at the Boise ONLC facility.

Conclusion

ONLC provided top-notch training with a small class size. The all participants remote setup worked well, but I recommend trying fully remote training for cost savings from your own office versus traveling to their in city facility locations.

Resources

ONLC Docker Training Classes & Certification

ONLC Dock Fundamentals Course Outline

ONLC Docker Fundamentals Slides LibreOffice Impress - password secured