So... Docker.  What do you want to know?

What are solaris zones?

Agnostic build environment?  Less setup.

Best practices on Dockerfiles?

Docker networking

Docker in AWS

Setup of a Safe environment

Questions

• Don't be shy

What is Docker?

Details of Docker

Basics of Docker

Container

Image

Engine

Hub

VM

Docker container

Lightweight

"...You may be able to run six to eight times as many containers as VMs on the same hardware."

http://www.infoworld.com/article/3072929/linux/containers-101-linux-containers-and-docker-explained.html

Typical workflow for docker

• Dockerize your code and dependencies
  • Write a Dockerfile that specifies the execution environment and pulls in your code.
  • If your app depends on external applications (such as Redis, or MySQL), run them in Docker as well (usually using a premade image available on Docker Hub)
  • Build, then run your containers as you develop.
     

Typical workflow for docker

• Configure networking and storage for your solution, if needed.
• Upload builds to a registry (docker's, yours, or your cloud provider’s), to collaborate with your team.
• If you’re gonna need to scale your solution across multiple hosts (VMs or physical machines), plan for how you’ll set up your cluster and scale it to meet demand.

Typical workflow for docker

• Finally, deploy to your preferred cloud provider (or, for redundancy, multiple cloud providers.)

Tonight

• Dockerize your code and dependencies  
• Setup a build pipeline for the container
• Upload builds to a registry (docker's, yours, or your cloud provider’s), to collaborate with your team.
• (Future meetup) If you’re gonna need to scale your solution across multiple hosts (VMs or physical machines), plan for how you’ll set up your cluster and scale it to meet demand.
• (Future meetup) Finally, deploy to your preferred cloud provider (or, for redundancy, multiple cloud providers.)
• Hands on labs

Why Docker?

I want to try it out.  How do I run Docker locally?

https://docs.docker.com/docker-for-mac

https://docs.docker.com/docker-for-windows

https://docs.docker.com/engine/installation/linux

Instant CI server

docker run -i -t -d --name neo4j --cap-add=SYS_RESOURCE \
-p 7474:7474 tpires/neo4j

Try out neo4j

docker run --name myjenkins -p 8080:8080 -v /var/jenkins_home jenkins

Play around with nginx

docker run -p 7070:80 -v \
/path/to/some/sample-static-html:/usr/share/nginx/html:ro -d nginx

How about mongo?

docker run --name my-mongo -d mongo

A developer's playground

Useful commands

https://github.com/wsargent/docker-cheat-sheet

How do I dockerize my app?

Manually create

You can create a docker image by just running commands against a base image.

docker pull learn/tutorial
docker run learn/tutorial apt-get install -y ping
docker ps -l
docker commit <id from previous step> learn/ping
docker run learn/ping ping google.com

Dockerfile

Instead of running commands and saving, can create a Dockerfile that specifies all the commands to build an image.

https://docs.docker.com/engine/reference/builder

FROM maven:3.3-jdk-8-onbuild-alpine

RUN mvn test

EXPOSE 8080

CMD ["java", "-jar", "target/docker-for-java-developers-0.1.0.jar"]

Dockerfile

Build the Dockerfile into an image and tag the image

docker build -t="myname/mytomcatapp:v1" .

Create a container by running the image

docker run -t -i myname/mytomcatapp:v1

Demo Catweb

https://github.com/ryanwalls/docker101

What about a real development pipeline?

Zero to Dockerized Image

• Fork/clone code
• Make changes, write tests
• Make sure container builds
• Submit PR
• Review/approve PR and merge
• Container build is kicked off automatically
• Once container built, deploy to QA
• One button push to production

Step 1: CI/CD

"Without continuous integration, we are nothing." 

-- Anonymous

See https://github.com/ryanwalls/docker-for-java-developers

Demo full life cycle at 3dsim

What's next for my company?

Zero to Docker

• Use docker for prototyping on local machines
• Run your CI/CD environment in Docker
• Get some small applications into containers
• Deploy containers instead of binaries in dev, integration, prod environments
• Orchestrate deploying those containers with a fancy tool (swarm, fleet, kubernetes, rancher, etc) to a cluster of servers
• Rinse...Repeat

Back to... why Docker?

(They will ask.)

Why Docker in Development?

• Fast prototyping
• Can easily create standalone multi-app dev environments (see Docker Compose)
• Use same stack as production
• Easily spin up machines to test large complex environments (see Docker Machine)

Why Docker in Production?

• Improved quality/stability/consistency.  Configuration of app stack is versioned and committed.  Ideally even immutable.
• Less work for techops.  Just provision bare linux machine
• Faster.  Setting up applications in new server is as simple as "docker run"
• Reduce costs. Apps run in their own container, so each server could have many apps running in nearly complete isolation.
• Fast deployments.  Docker uses diff file system for images.  Any layers already run are cached.

Adoption and interest still climbing

• 100% increase in container usage in production since 2015 survey.  
• 79% of companies surveyed use containers

https://clusterhq.com/assets/pdfs/state-of-container-usage-june-2016.pdf

https://blog.docker.com/2016/05/vm-or-containers

https://resources.codeship.com/ebooks/why-containers-and-docker-are-the-future

More ammunition

What about clustering and microservices?

Courtesy of http://blog.giantswarm.io/getting-started-with-docker-and-meanjs

Lots of choices

• Docker Swarm
• Kubernetes
• Amazon ECS
• Rancher
• Mesos
• Fleet
• Etc, etc, etc...

Best answer early 2015...

Best answer late 2017...

Questions?

Hands on labs

• Setup
• Running your first container
• Webapps with Docker
• Deploying a Multi-Service App in Docker Swarm Mode

For those who don't have Docker installed, use the in browser tutorials here:

http://training.play-with-docker.com/dev-stage1

All this child's play?  Check out all the tutorials:

http://training.play-with-docker.com/alacart