This document discusses why developers should use Docker containers. It notes that Docker can help solve problems with reproducibility across environments by packaging applications and dependencies into self-contained units. An example is provided of a Dockerfile for a Java Spark application that defines what is needed to build and run the application in a container. The document encourages asking questions and experimenting with Docker to take advantage of its benefits like ease of use, large community support, and speed.

1. Why
A talk by
Alex Bolboaca
alex.bolboaca@mozaicworks.com
You
Start Using
Should

2. About Me
● Polyglot programmer
● Trainer
● Coach
● Not a Docker expert; a fan
● Not affiliated with docker

3. I Noticed a Trend

4. Why DevOps? Agile!
Reduce time to market & Adapt fast to change
Scrum for dev teams
Bugs & Code difficult to change
Changeable Design
Automated testing
CI
Etc.
Operations Problems
Fast feedback
on infrastructure
+ many others

5. Annoying Problems
“It works on my computer”
Black Tuesdays
“Cannot reproduce”
I have errors nobody else has

6. Containers to The Rescue

7. Actually, these containers

8. Work with Containers
● Each component of your application runs in a
container
● Dependencies are included in each container
● Containers are shared by all developers,
sysadmins, operations etc. through SCC (eg. git)
● Containers are deployed as such

9. Example: Java 8 Spark App
Dockerfile

10. Workflow
● Build the container
– Write the dockerfile
– Build it with docker. E.g. docker build -t [name]
● Commit the dockerfile OR the resulting image
● Run the container locally
– Mount any folder needed (e.g. the source files during dev, the
compiled app for production)
● Deploy the container
– Docker needs to be installed on server

11. Example: Java 8 Spark App
Dockerfile
It worked on my computer!

12. Quick Demo

13. Why Use Docker?
Easy to start with
Free
Large community
Fast

14. Your Questions?
“The important thing is
not to stop questioning”