Introduction to Docker
Andrew T. Baker
Today
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What is Docker?
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Docker vocabulary
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Docker's past, present, and future
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Your future in the cloud
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Questions
Virtualization tool?
Configuration manager?
VM manager?
cgroups?
LXC?
libvirt?
go?
Docker.com says
Docker is an open platform for developers and sysadmins to build, ship, and run distributed applications.
Docker Engine
A portable, lightweight runtime and packaging tool
Docker Hub
A cloud service for sharing applications and automating workflows
Less portable, minimal overhead
Most portable,
lots of overhead
Manual
configuration
Traditional VMs
CM tools
Docker
Containers
Your applications run in containers
$ docker run busybox /bin/echo "hello world"
hello worlddocker run [OPTIONS] IMAGE [COMMAND] [ARG...]
Images
Saved states of containers.
$ docker history atbaker/sd-django
IMAGE CREATED CREATED BY SIZE
2c69173d3c3e 6 months ago /bin/sh -c apt-get clean && rm -rf /var/lib/a 7 B
cf07ee82aaa6 6 months ago /bin/sh -c chown root /opt/sd_client.py /var/ 1.162 kB
4a3046bdcd25 6 months ago /bin/sh -c #(nop) ADD file:0854b61af5a8f7051c 259 B
519ac326d2de 6 months ago /bin/sh -c #(nop) ADD file:03065d55ff7e64caa9 896 B
5f87ccb7c84f 6 months ago /bin/sh -c chown root /etc/service/gunicorn/r 871 B
aa069b102781 6 months ago /bin/sh -c #(nop) ADD file:4683e735d1f7a57fd5 864 B
da64e86860ea 6 months ago /bin/sh -c mkdir /etc/service/gunicorn 7 B
9109839d1887 6 months ago /bin/sh -c touch /var/log/gunicorn/error.log 7 B
5e628a947f45 6 months ago /bin/sh -c touch /var/log/gunicorn/access.log 7 B
57b25445ef0b 6 months ago /bin/sh -c mkdir /var/log/gunicorn 7 B
dc008bbf46e8 6 months ago /bin/sh -c /var/www/venv/bin/django-admin.py 747.5 kB
d75444a0b891 6 months ago /bin/sh -c /var/www/venv/bin/django-admin.py 45.49 kB
4b6f8f5021aa 6 months ago /bin/sh -c #(nop) ENV SECRET_KEY=no-so-secret 0 B
93a3749a8817 6 months ago /bin/sh -c #(nop) ENV DJANGO_SETTINGS_MODULE= 0 B
3d67fca00fe8 6 months ago /bin/sh -c #(nop) ENV PYTHONPATH=$PYTHONPATH: 0 B
1b2851b048f7 6 months ago /bin/sh -c /var/www/venv/bin/pip install -r / 30.19 MB
7c9a3b2daefb 6 months ago /bin/sh -c virtualenv /var/www/venv 11.62 MB
6b468cc8cefe 6 months ago /bin/sh -c pip install virtualenv 1.921 MB
Dockerfiles (builder)
Series of commands to build an image
# Spin-docker example dockerfile for a Django project
# Use phusion/baseimage as base image
FROM phusion/baseimage:0.9.8
MAINTAINER Andrew T. Baker <andrew@andrewtorkbaker.com>
# Add the Django app and install its requirements
ADD sd_sample_project /var/www/django
RUN apt-get install -y python-pip
RUN pip install virtualenv
RUN virtualenv /var/www/venv
RUN /.../venv/bin/pip install -r /.../requirements.txt
...Docker
Repository
Git
Repository
collection of commits
Container
Checkout
used for local execution
Docker Hub
GitHub
popular remote server
Image
Commit
saved state
An open-source
success story
- dotCloud side project revealed at PyCon 2013
- Since then:
- 100 million Docker Engine downloads
- 45,000 "Dockerized" applications in Docker Hub
- 720+ community contributors
- 18,000+ GitHub stars
- dotCloud changes its name to Docker
1.0 released in June 2014
Source: Docker tweet
Source: Docker blog
What are people doing with Docker?
Development environments
Platform-as-a-Service (PaaS)
Continuous Integration (CI)
Educational sandboxes
And the tools are getting better too
boot2docker
Docker library images
GUIs
Cloud-agnostic hosting
Container-specific hosting
Container-specific hosting
Container-specific hosting
What's next
for Docker?
2014
- Get to 1.0 (production-ready)
- Establish partnerships
- Round out some rough edges (v1.3)
2015
- Make Docker easier to use
- Popularize best practices for scaling
- "Include more batteries" (w/o cannibalizing ecosystem)
- Address security concerns
Containers,
the cloud, and you
A new player
Cloud computing average monthly cost
Source: RBC Capital / Business Insider
Switching clouds
in minutes for...
- Service outages
- CPU/Network/IO performance
- Special pricing tailored just for you