This document provides an introduction to Docker and DevOps. It defines DevOps as combining software development and IT operations to shorten development cycles and deliver features quickly. Docker is described as using containers to decouple applications from operating systems, providing a lightweight virtualization alternative to VMs. Key Docker concepts are outlined like Dockerfiles, images, and registries. Guidelines are provided around keeping images small and being careful with databases in containers. Kubernetes is also mentioned as a popular container orchestration engine.

1. Hello, Docker!
An Introduction to Docker
Michael K. Essandoh

2. Michael Kwesi Essandoh @mexcon_mike
● Senior Software Engineer, ANDELA
● Director, TAISE
● Technical Consultant
● Ex: Petra Trust, VasSoft, Bsystems Limited
● .NET Fanatic

3. Outline
● What is DevOps?
● What is Docker?
● Containers vs VM
● Advantages of Docker
● Concepts
● General Guidelines
● Honourable Mention
● Resources
● QA
● DEMO

4. What is DevOps?
● A set of practices that combines software development (Dev) and IT (Ops) to
shorten the systems development life cycle while delivering features, fixes,
and updates frequently.
● Combining the right tools and culture to innovate rapidly
● DevOps is a culture
○ Agile principles
○ Error tolerance
○ Post mortems
● You can’t buy DevOps

5. What is Docker?
● Containers
○ Decouple applications (and their environments) from operating system
○ Virtualizes user space
○ More lightweight and portable compared to HyperVisor based virtualization
○ Go to option for microservice architecture
○ Ephemeral storage by default*
● Docker
○ Development tool and runtime environment for containers
○ Released March 13, 2013
○ Runs on Linux, MacOS and Windows
○ Alternatives: lxc, rkt, containerd*

6. Containers vs VM
Twistlock

7. Advantages of Docker
● Shorten development time
● Portable
● Standardization
● Minimal resource overhead
● Isolation
● MicroService architecture

8. Docker Concepts
● Dockerfile
○ Set of instructions or specifications that define the
structure of a container
● Image
○ Read-only templates
○ Static specification of what a container should be at
runtime
● Registry
○ Storage and distribution of images
○ Can be private
○ Local, DockerHub, Quay, AWS ECR, Red Hat
Container Catalog etc
Twistlock

9. General Guidelines
● Follow the Twelve-Factor App guidelines
● Keep images as small as possible
● Databases
○ Be careful. Especially in production
○ Caches - Memcache, Redis
● Security
○ Use trusted images from trusted sources
○ Code defensively
○ Don’t run as root

10. Honourable Mention: Kubernetes (k8s)
● Orchestration engine
● Initial release: 7 June 2014
○ Built by Google, mid-2014
○ Handed over to CNCF
● Cluster
○ Control
○ Data
○ Workers
● Competition
○ Docker Swarm
○ Mesosphere
○ Cattle (Rancher)
○ Portainer*
● k3s

11. Resources
● The Twelve Factor App
● Docker Docs
● Landscape CNCF
● Gists (BlitzinBuffalo)

12. QA

13. DEMO

14. The End
To God Be The Glory