Docker and Kubernetes

What is Docker?

  • Docker is a platform that allows one to develop and deploy applications in a isolated manner along with all of their dependencies.

Why Use Docker?

For a more extensive discussion of Docker’s advantages see Schenker’s Learn Docker – Fundamentals of Docker 18.x, specifically Chapter 1.

  • Automation – Using containers significantly increases the amount of automation that can occur.
  • Cost Savings – By using a thin layer as opposed to the thicker Virtual Machine model it allows more processes to be run on less hardware.
  • Developer Productivity – Allows for the creation of reusable and shareable development environments.
  • Deployability – It is easier and quicker to deploy applications to production when containerized.
  • Security – Use isolation built into Docker containers to keep applications from affecting one another.
  • Scalability – Using Kubernetes one can scale one’s applications massively.

Docker Commands

The Docker CLI can be used in a number of different ways, some of the more common commands are listed below. In general, a Docker command follows this form:

  • begins with docker (the name of the CLI we are using),
  • a context (like containers),
  • a command (like run), and
  • can include specific processes to run in the container.
  • The end result: docker thecontext thecommand theprocess

Docker General Commands

Check Docker Version:docker --version
Details About Installed Version:docker info
View Docker CLI Help:
Can also be run in a specific context/on a command like:		docker --help
docker container ls -h
Login to Docker Public Registry:docker login

Docker Container Commands

Start Container:
– If we do not have a local copy of the image it will be pulled from the Docker repository.
– Use --d to specify that this is a Linux daemon. Use --name to provide a friendly name for the container.		docker run name-of-container
Gracefully Stop Container:
– If we have provided a container with a friendly name we can use that instead of the hash.		docker container stop <hash>
Force Container Shutdown:docker container kill <hash>
List All Containers:docker container ls --all
Show Only Running Containers:docker container ls
Give Container Friendly Name:docker build -t name
Run Container Interactively:docker run --interactive --tty name-of-container bash
Run Container Detached:
– Example: docker run --detach --publish 80:80 --name nginx
– One can use -P to map all ports.		docker run --detach --publish <port>:<port> --name <name-of-container> <name-of-image>
Attach to Running Container:
– To exit container without stopping press: Ctrl+P Ctrl+Q		docker container attach <nameofcontainer>
Remove specified container from local machine:
– Use -f or --force to force the removal.		docker container rm <hash>
Inspect Container:docker container inspect <name>
View Container Logs:
– Use --tail or -t before nameofcontainer to get only the tail of the logs (include number of lines to return)
– Use --tail with --flow in above manner to continue getting newer log entries.		docker container logs <nameofcontainer>
View Container Diff:
– Shows a list of files added/modified/deleted since the base layer.		docker container diff <nameofcontainer>

Docker Image Commands

List Downloaded:docker image ls
Associate Image with username/repo and tag:docker tag image username/repository:tag
Publish to the Repository:docker push username/repository:tag
Remove specified image from local machine:docker image rm <image id>
Persist Changes to a Container Into a New Image:docker container commit <name-of-container> <name-of-image>
View Changes Made to Build Image:docker image history <name-of-container>

Docker Virtual Machine Commands

List Virtual Machines:docker-machine ls
Connect to Docker Virtual Machine:docker-machine ssh nameofvm

Other Useful Docker Commands

Get the IP address assigned to a container:docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' name-of-container

Dockerfile

Docker Compose

Minikube Commands

  • Start:minikube start
    • If running on Windows you may need to specify if you are using Hyper-V:
      minikube start --vm-driver=hyper --hyperv-virtual-switch="Name of Switch"

Kubernetes Commands

Tooling

Terminology

Some Other Stuff…

  • Start with Install Docker for Windows.
  • Then Get Started with Docker for Windows.
  • Docker for Windows runs in the taskbar notifications area.
    • You’ll want to check “Expose daemon on tcp://localhost:2375 without TLS” if using PhpStorm.
    • Allows one to configure auto startup, sharing local drives with containers (only needed for Linux containers), set resources used by Docker, configure network, proxies, configure registries (where images are hosted), Kubernetes, reset configuration, and etc.
  • Using Docker with MariaDB.

Bibliography