in 30 minsSteve Poole, IBM

@spoole167

the promise

Ship a complicated software environment that leaves no trace when finished…

Be total confident that if it works for me it will work the same for you

https://localhost:9043/ibm/console/logon.jsp

docker run --name test -h test -v $(pwd)/PASSWORD:/tmp/PASSWORD \ -p 9043:9043 -p 9443:9443 -d ibmcom/websphere-traditional:install

The basics

Docker Engine

Server(Long

running Daemon)

Host (linux)

REST API

CLI

You

Image Image

UI

Registry

Docker Engine

Server(Long

running Daemon)

Host (not linux)

REST API

CLI

You

Image Image

UI

VM (linux)

Registry

Docker Engine

DaemonAPI

You

Image Image

Host

Registry

Docker Engine

Daemon

Host

API

You

Image Image

docker run -d –p 8080:80 presentation

Registry

Docker Engine

Daemon

Host

API

You

Image Image

Registry

Presentation

Image cache

Container

8080

:8080

:80

docker run -d –p 8080:80 presentation

docker run -d –p 8081:80 presentation

docker ps

quick check• Images are the unit of delivery. You only share images• Images are immutable• Images are stored in local caches or shared via registries.• DockerHub is a central point Think “github” for docker images• Containers are the runtime units. They run on a single host• Containers retain state until terminated• Containers are the unit of scale.

• docker ps lists the running containers • docker ps -a lists all containers

Let’s build a Docker Image

docker build -t presentation .

Docker images are layers in a union file system. Each layer overlays the ones before:

presentation

eboraas/apache

eboraas/debian

eboraas/debootstrap

Dockerfile - automated image creationFROM eboraas/apache COPY ./DockerIn30Minutes /var/www/html

Where’s the command to run the apache server? I inherited it

FROM eboraas/debian:stableMAINTAINER Ed Boraas <ed@boraas.ca>

RUN apt-get update && apt-get -y install apache2 && apt-get clean \ && rm -rf /var/lib/apt/lists/*

ENV APACHE_RUN_USER www-dataENV APACHE_RUN_GROUP www-dataENV APACHE_LOG_DIR /var/log/apache2

RUN /usr/sbin/a2ensite default-sslRUN /usr/sbin/a2enmod ssl

EXPOSE 80EXPOSE 443

CMD ["/usr/sbin/apache2ctl", "-D", "FOREGROUND"]

quick check• Dockerfiles are the normal way to create docker images.

• Usually:

• has a name of image to inherit from• has a set of build instructions to run at build time• has some runtime instruction (ie what to start)

Docker Engine

Daemon

Host

API

You

Image Image

Registry

Presentation

Image cache

Container

8080

:8080

:80

Docker Engine

Daemon

Host

API

You

Image Image

Registry

pres

Image cache

Container

8080

Container

8081

apache

debian

Volumes• Think of containers as mini VM’s • Any mutations made to the containers contents will be lost when the

container is stopped• How to share or persist state?

• Two options..

docker run -d -v $PWD:/var/www/html p 8082:80 —t presentation

Think of as an nfs mount style command

mounts a local directory on the host over the top of a directory in the container

Both directory paths must be absolute

The container can read/write the contents of the host file system

-v

VOLUME command

VOLUME /data

Dockerfile command to create a persistent data store on the host system that isaccessed inside the container at the path given.

Volumes persist on the host until deleted.

Volumes are a great way to share state between containers

docker run -d —volumes-from container image

auto magically mount the volumes created by another container

Docker Engine

Daemon

Host

API

You

Image Image

Registry

pres

Image cache

Container

8080

Container

8081

apache

debian

It’s getting messy

• Let me introduce kitematic

Advanced section• Docker for encapsulating a single instance of a complex environment is

useful

• Docker as the packing and deployment of an single micro service is compelling

• Docker tools exist to network containers together and to scale and load balance across multiple hosts and data centres.

• Containerisation is the enabler for industrial application deployments on truly gigantic scales.

Docker compose• “Compose is a tool for defining and running multi-container Docker

applications. With Compose, you use a Compose file to configure your application’s services. Then, using a single command, you create and start all the services from your configuration”

• https://docs.docker.com/compose/overview/

version: '2'

services: dbserver: image: couchdb ports: - "5984:5984" volumes: - ./.couchsummary:/usr/local/var/lib/couchdb

dbteam: image: couchdb ports: - "5985:5984" volumes: - ./.couchteam:/usr/local/var/lib/couchdb

teamserver: image: dashboard build: . command: bundle exec rackup -s puma -p 8080 volumes: - .:/dashboard ports: - "80:8080" depends_on: - dbteam environment: MODE: team TEAM: test DBURL: http://dbteam:5984/

There’s more - but thats for another talk

thank you.