wagoodman / docker-cert-study-group-notes

Notes through the book Docker Deep Dive as we read it to prepare for the Docker Certified Associate exam

Meeting Notes

5/31

• Wyn led dicsusion through Docker Deep Dive Chapters 1-4 (see notes below)
• Next meeting chapters 5-9, 1 chapter each person

TODO:

• make list of exercises that will train on hands-on, prod bugs, etc

Resources

• Docker Certification site w/Study Guide
• Docker Certified Associate Exam Prep Guide - w/links from exam bullets
• Interactive Scenarios - Kubernetes, Docker, etc - Katakoda
• Play with Kubernetes
• Play with Docker Enterprise
• Docker Swarm Workshop, J. Petazzo
• Linux Container from Scratch, Joshua Hoffman
• Wyn's Kubernetes Workshop

Docker Deep Dive Notes

1. Containers from 30,000 feet
   • What are containers, etc
   • Windows vs Linux
2. Docker
   • Kubernetes - leading orchestrator, needed for managing deployment and running apps
   • Docker Engine - plumbing that runs and orchestrates containers
   • EE vs CE
   • Moby - tools that combine to make Docker daemon. Breaks dDOcekr into modular components. Big infra contributors. Golang.
     • Batteries included but removable
   • Open Container Initiative (OCI) - standardized image format and container runtime
3. Installing Docker:
   • Windows, Mac, Windows Server 2016, Ubuntu, Docker EE, etc
   • Upgrading Docker:
     • make sure containers have restart policy,
     • drain nodes if needed (using Swarm mode).
     • Steps:
       • Stop Docker daemon, remove old version, install new version, configure new version to auto start when system boots, ensure containers restarted.
   • Docker and storage drivers
     • Every Docker container gets an area of local storage where image layers are stacked and the container filesystem is mounted. By default this is where all container read/write ops occur, making it integral to the perf and stability of every container.
     • Local storage area has been managed by storage driver, which are sometiomes called the graph driver. Docker supports several different storage drivers, each which implements layering and copy-on-write in its own way - impacting perf and stability.
       • Some available drivers:
         • aufs (the original and oldest)
         • overlay2 (probably best choice for future)
         • devicemapper
         • btrfs
         • zfs
       • Windows only supports windowsfilter driver
4. The Big Picture
   • Ops perspective
     • Docker client,
     • daemon/engine,
     • images, running containers
     • attaching to running containers
     • Dev perspective - containerize app