Using Docker

Scott Morningstar

Caktus Consulting Group

April 25, 2014

./images/SuperFamous1.jpg

Photo Credit.

Presenter Notes

  • Notes for the intro

What is Docker

  • Docker is an open-source project to easily create lightweight, portable, self-sufficient containers from any application.

Presenter Notes

  • The same container that a developer builds and tests on a laptop can run at scale, in production, on VMs, bare metal, OpenStack clusters, public clouds and more

What is Docker Really

  • Docker is Git for your whole application

Presenter Notes

Why Docker

  • Content agnostic
  • Hardware agnostic
  • Content isolation and interaction
  • Automation
  • Highly efficient
  • Separation of duties
More Information Here.

Presenter Notes

  • Runs Anywhere
  • On Anything
  • Each part runs in it's own container
  • Automation is baked in and easy
  • No Hypervisor overhead, Very little IO over head
  • The pieces are reusable

Requirements

  • Linux with a modern kernel (At least 3.8)
  • aufs (optional but recommended)

Installation instructions Here.

Presenter Notes

  • advanced multi layered unification filesystem

Docker Terminology

  • Image = Read only snapshot
  • Container = Instantiation of an image
  • Registry = Storage for repository (Think Pypi)
  • Repository = Shareable collection of tagged images that together create the file systems for containers

Presenter Notes

  • Docker uses words different words for the same thing.

Basic Commands

docker pull <repository> (Pull and image from a registry / repository)

docker images (list local images)

docker ps (list running containers)

docker run -i -t <image> <command> (-i Keep stdin open even if not attached -t Allocate a pseudo-tty )

Presenter Notes

An example

docker pull ubuntu:latest

docker run -i -t ubuntu bash

Presenter Notes

  • Pull a image from a repository and run it

Docker Files

# DOCKER-VERISON 0.8.1

from ubuntu:12.04
run apt-get update
run apt-get -y install wget nginx-light

run echo 'daemon off;' >> /etc/nginx/nginx.conf

run cd /tmp && wget http://download.elasticsearch.org/kibana/kibana/kibana-3.0.0milestone5.tar.gz -O - | tar xzvf -
run cp -R /tmp/kibana-3.0.0milestone5/* /usr/share/nginx/www

expose 80

cmd /usr/sbin/nginx

Presenter Notes

  • Docker files describe commands to run on container instantiation
  • This one pulls in Ubuntu 12.04, installs nginx and kibana
  • but not elastic search

Build and run

docker build --rm -t caktus/kibana .
docker run -d  -p 8080:80 caktus/kibana:latest
docker ps

Presenter Notes

  • Kibana running on port 8080
  • but no elastic search

Add ElasticSearch

  • Now we need to run another process
  • Oh No

Presenter Notes

  • Docker only runs one process in a container
  • Docker feels strongly about this
  • Other processes we might want in a container sshd, rsyslog

Supervisor would be good for this

Presenter Notes

New Dockerfile

# DOCKER-VERISON 0.8.1

from ubuntu:12.04


run apt-get update
run apt-get -y install wget nginx-light openssh-server supervisor

run echo 'daemon off;' >> /etc/nginx/nginx.conf

RUN mkdir -p /var/run/sshd
RUN mkdir -p /var/log/supervisor

ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf

run cd /tmp && wget http://download.elasticsearch.org/kibana/kibana/kibana-3.0.0milestone5.tar.gz -O - | tar xzvf -
run cp -R /tmp/kibana-3.0.0milestone5/* /usr/share/nginx/www

expose 80 22

CMD ["/usr/bin/supervisord"]
  • docker run -t -i -p 8080:80 -p 2222:22 -p 9200:9200 -p 9300:9300 caktus/kibana2:latest

Presenter Notes

  • We also add sshd and now we start supervisor

Now for Elastic Search

# DOCKER-VERISON 0.8.1
from ubuntu:12.04
from dockerfile/java

run apt-get update
run apt-get -y install wget nginx-light openssh-server supervisor

run echo 'daemon off;' >> /etc/nginx/nginx.conf

RUN mkdir -p /var/run/sshd
RUN mkdir -p /var/log/supervisor

ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf

run cd /tmp && wget http://download.elasticsearch.org/kibana/kibana/kibana-3.0.0milestone5.tar.gz -O - | tar xzvf -
run cp -R /tmp/kibana-3.0.0milestone5/* /usr/share/nginx/www
# Install ElasticSearch.
RUN wget https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.1.1.tar.gz
RUN tar xzf elasticsearch-1.1.1.tar.gz
RUN mv elasticsearch-1.1.1 /opt/elasticsearch
RUN rm elasticsearch-1.1.1.tar.gz

# Expose ports.
#   - 9200: HTTP
#   - 9300: transport
EXPOSE 9200
EXPOSE 9300
EXPOSE 80
EXPOSE 22
CMD ["/usr/bin/supervisord"]

Presenter Notes

  • docker run -t -i -p 8080:80 -p 2222:22 -p 9200:9200 -p 9300:9300 caktus/kibana2:latest

Thanks

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Resources

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Info

Slides

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