Docker Festival
Dreaming about Docker
Lucas van Lierop Matthias Noback
@lucasvanlierop @matthiasnoback
#dockerfestival

Program for today
09:30 Introduction
10:00 Workshop
12:45 Lunch
13:45 Best Practices
14:15 Workshop
16:15 Share results

The container revolution; why is it
so good?

Self-contained deployable units
Application code, configuration and dependencies, all-in-one
Instead of:
● (Manually) pre-configured server
● Pulling code changes

Image-based deployments
No build steps on the production server
Instead of:
● Building the software on the production server
● Non-deterministic builds

Limited abilities
Containers run in isolated environments
Instead of:
● Processes that implicitly have access to everything on the machine

Scheduling
Built-in resource management, rebalancing, scaling (even within one host)
Instead of:
● Custom tooling (Marathon, DC/OS, Consul)

What the container revolution
encourages

Single Responsibility Principle
Focus on limited responsibilities per container/service.

Open/Closed Principle
Modify the behavior of a container by configuration through environment
variables and secrets.

Architecture considerations
Focus on clear
specifications for how the
service is connected to its
surroundings.
http://alistair.cockburn.us/Hexagonal+architecture

Focus on "everything in a box"
Self-contained, explicit, no loose ends.
https://12factor.net/

No attachment to servers
● No manual actions on the server
● Provisioning fully automated
● Pets vs kettle
● Destroyable and recreatable infrastructure

What the container revolution
enables

Continuous delivery
Container image: an actual build artifact

Polyglot programming
● Code
● Persistence

Scaling of software units
Number of instances (horizontal scaling)
versus the power of one instance (vertical scaling)

Scaling for organizational units
Number of teams, number of projects (horizontal scaling)

Monolithic and service-oriented
development side-to-side
Containers encapsulate internal technologies;
combine multiple programming models and paradigms in one system.

What it requires
What it
requires
What it
enables

Operations skills
Configuration, server management, monitoring, emergencies, recovery

Knowledge
About technologies used

Shared responsibility
Writing the code, and make it run in production (and keep it running).

Long story short: DevOps culture

DDD, BDD
Operations
UX, Design

Let’s get started

In the morning: two options
- Docker Introduction (Docker Engine, Compose, Machine, Swarm)
- Your Next Step

Different stages of using Docker
1. Side project
2. Development environment (e.g. instead of Vagrant)
3. For Continuous Integration (CI) (stable CI environment)
4. Deployment to a staging and/or production environment
5. Images as build artefacts in a pipeline for Continuous Delivery
6. Improve resilience of containers in a production environment

Use this day to take the next step

Time flies Pick small tasks, create issues
Check every half hour: am I still on track?
Share useful snippets, articles, etc.
Celebrate and share success
https://github.com/lucasvanlierop/docker-festival-workshop