What is Docker?

Details of Docker

Basics of Docker

Container

Image

Engine

Client

Hub

VM

Docker container

Why Docker?

What is Dockerizing?

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

https://www.docker.com/tryit

Extra credit: If you're comfortable with creating manual docker images and don't need the tutorial, try out Docker Swarm

https://github.com/docker/swarm

Dockerfile

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

e.g.  Dockerfile for deploying a .war that we have archived in artifactory.

FROM tutum/tomcat

ADD <Artifactory url>/my-app-0.1-SNAPSHOT.war $CATALINA_HOME/webapps/my-app.war

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

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

Another

FROM java:8-jre

ENV CATALINA_HOME /usr/local/tomcat
ENV PATH $CATALINA_HOME/bin:$PATH
RUN mkdir -p "$CATALINA_HOME"
WORKDIR $CATALINA_HOME

# see https://www.apache.org/dist/tomcat/tomcat-8/KEYS
RUN gpg --keyserver pool.sks-keyservers.net --recv-keys 05AB33110949707C93A279E3D3EFE6B686867BA6 
ENV TOMCAT_MAJOR 8
ENV TOMCAT_VERSION 8.0.18
ENV TOMCAT_TGZ_URL \
https://www.apache.org/dist/tomcat/\
tomcat-$TOMCAT_MAJOR/v$TOMCAT_VERSION/bin/apache-tomcat-$TOMCAT_VERSION.tar.gz

RUN curl -SL "$TOMCAT_TGZ_URL" -o tomcat.tar.gz \
	&& curl -SL "$TOMCAT_TGZ_URL.asc" -o tomcat.tar.gz.asc \
	&& gpg --verify tomcat.tar.gz.asc \
	&& tar -xvf tomcat.tar.gz --strip-components=1 \
	&& rm bin/*.bat \
	&& rm tomcat.tar.gz*

EXPOSE 8080
CMD ["catalina.sh", "run"]

Getting Started

Docker Machine

to the rescue

https://github.com/docker/machine

# Assumption: You've installed Docker and Virtualbox
# Installing docker-machine
git clone https://github.com/ryanwalls/docker-demo

cd docker-demo

cp docker-machine /usr/local/bin/

# Create a docker host
docker-machine create --driver=virtualbox dev

# (Optional) Look at some information about your machine
docker-machine inspect dev

# Set your docker client to connect to the dev machine you just created
$(docker-machine env dev)

# (Optional) Try saying hello from your dev machine
docker run busybox /bin/echo 'Hello world'

Fire up first docker container

Dev Fun

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

Useful commands

# list docker machines
docker-machine ls

# get list of commands
docker-machine

# init shell for docker to connect to a given machine
$(docker-machine env <name of machine>)

# Get list of commands
docker 

# Check logs
docker logs <name of container>

# Start shell inside running container
docker exec -i -t <containerIdOrName> /bin/bash

Docker Machine

Docker

Multiple Component Apps

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

Linking with Docker

# Clone the repo
git clone https://github.com/luebken/mean.git 
cd mean

# Start mongo
docker run -p 27017:27017 -d --name db mongo

# Build the Dockerfile for the UI
docker build -t mean .

# Run the UI image
docker run -p 3000:3000 --link db:db_1 mean

Inspired by http://blog.giantswarm.io/getting-started-with-docker-and-meanjs

Using Docker Compose (fig) instead 

web:
  build: .
  links:
   - db
  ports:
   - "3000:3000"
   - "35729:35729"
  volumes:
   - ./app:/home/mean/app
  environment:
   NODE_ENV: development
db:
  image: mongo:latest
  ports:
   - "27017:27017"

Inspired by http://blog.giantswarm.io/getting-started-with-docker-and-meanjs

Using Docker Compose (fig) instead 

# Install Docker Compose
curl -L https://github.com/docker/fig/releases/download/1.1.0-rc2/docker-compose-\
`uname -s`-`uname -m` > /usr/local/bin/docker-compose; chmod +x /usr/local/bin/docker-compose

# Run docker-compose
docker-compose up

Inspired by http://blog.giantswarm.io/getting-started-with-docker-and-meanjs

Multiple Component Multiple Host  

Apps

Lots of choices

• Docker Swarm
• Kubernetes
• Mesos
• Shipyard
• Longshoreman
• Fleet
• Rancher
• Etc, etc, etc...

It's complicated

http://stackoverflow.com/questions/27640633/docker-swarm-kubernetes-mesos-core-os-fleet

What we're trying next....

http://shipyard-project.com with https://github.com/ehazlett/interlock#shipyard-integration 

What's next for my company?

Zero to Docker

• Use docker for prototyping on local machines
• Get some applications or infrastructure into containers
• Deploy containers instead of binaries in dev, integration, prod environments
• Orchestrate deploying those containers with a fancy tool (swarm, fleet, shipyard, kubernetes, etc)
• Rinse...Repeat

Back to... why Docker?

(They will ask.)

Why Docker in Development?

• Fast prototyping
• Can easily create standalone multi-app dev environments
• Use same stack as production
• Easily spin up many machines

Why Docker in Production?

• Improved quality/stability/consistency.  Configuration of app stack is versioned and committed.
• 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.

https://docs.docker.com/#why-docker

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