Docker.io for Developers

What are these crazy containers you speak of?

Who am I?

Dennis Reams

Crusty Ole Developer

• I'm learning Docker, just like the rest of the world.
• Showing you why Docker interests me, a developer.
• Interested in what you think and have learned about Docker too.
• Bottom Line: Don't be afraid to contribute to this session, I need all the help I can get.

What am I doing up here?

Agenda

• Basics of Docker
• Docker Lifecycle
• Docker In Action (Demo Time)
• Dockerfile
• Demo App
• Reference Material

Basics of Docker

From Docker: Docker is an open platform for developers and sysadmins to build, ship, and run distributed applications. Consisting of Docker Engine, a portable, lightweight runtime and packaging tool, and Docker Hub, a cloud service for sharing applications and automating workflows

From Wikipedi: Docker uses resource isolation features of the Linux kernel such as cgroups and kernel namespaces to allow independent "containers" to run within a single Linux instance, avoiding the overhead of starting virtual machines

From Me: One BIG A$$ closure.

Definition of Terms

• Virtual Machine (VM) 
  • emulation of a computer system
  • full OS must be installed on each instance 
• Image (aka Virtual Machine Image)
  • file consisting of a pre-configured OS and a single application.
• Container (aka LinuX Container(LXC))
  • OS level virtualization for running multiple isolated Linux systems from a single host

Layman's terms please...

• Docker Engine
  • A container hosting service that allows one to many containerized apps to run on a single OS by leveraging LXC
• Docker Hub
  • Cloud based virtual image repository
  • Think maven repo or cdn.js for virtual machines
  • Access to official/supported images as well as crowdsourced contributions.

Container Lifecycle

• Pull container image (from Docker Hub)
• Build a container image
• Run a container image
• Start/Stop a container image
• Push container image (to Docker Hub)
• Remove a container/image

Docker Essentials

• docker ps
  • list any running containers
• docker ps -a
  • list any containers
• docker logs -f {ur container id here}
  • display STDOUT & STDERR for a container
• docker rm {ur container id here}
  • remove a stopped container
• docker rmi {ur image tag id}
  • remove old images from your local machine

Docker Parameters

• docker -i
  • interactive mode - comm via command line
• docker -d
  • detached mode - comm via network connection.
• docker -v
  • set data volumes in the container
• docker --volume-from {container name}
  • allows hosting data volumes on another container.
• docker --link {container name}
  • establishes communication between two containers.

Stop... Demo Time

• DockerFile
• Coding my environment set up
• Demo Application
• Swapping Datasources
• Resetting Stateful Data

What's Next?

• Continuous Integration
  • Automate this stuff!
• Off loading work to other containers
  • Logging
  • Minecraft example - "The cool stuff"
• Containers as Content Management System
•  
• How do you scale all this?

Reference Materials

• docker.io
• Docker Hub
• Docker CLI Docs
• Docker Lifecycle Cheat Sheet
• Using Docker on OSX

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Contact Info:
Dennis Reams
Twitter: @dennis77pr

Slides @ slides.com

Code @ GitHub