Containers?

Containers are not VMs

Physical Servers are Cities

City

• Streets
• Water system
• Power Grid
  
   
• Highways

Servers

• CPU
• RAM
• Storage
  
   
• Network

VMs are Houses

House

• own plumbing
• own heating
• own power distribution
• own doors & fences

VM

• full OS
• own network stack
• own kernel
• own firewall

Containers are Appartments

Appartment

• shared plumbing
• shared heating
• shared power distribution
• shared doors & fences

Container

• minimal OS
• shared kernel
• common Container engine
• shared firewall

Containers?

• Lightweight: really only what is necessary
• Fast: start in milliseconds
• Secure: full separation between containers
• Microservices: one container = one service
• Can still run on VMs :)

Who uses containers?

• Your friendly Drupal Hosters
• VISA (100,000 transactions per day)
• Netflix (1 Mio containers per week)
• Alibaba (12 billion dollars on Singles Day)

Docker?

Docker 

• Docker Engine
  • Executing, Monitoring, Network, Storage, Security, Plugins
• Docker Images
  • Representation of full App saved in Layers
• Docker Registry
  • Storage for Docker Images
• Docker Swarm
  • Orchestration

Orchestration 

• Docker Swarm, Kubernetes, OpenShift, Rancher
• Containers are not persistent
• Orchestration systems make enough containers are running

Why should I care?

• Dockerfiles can be written by developers
• Docker allows to run more then just Drupal
• Containers are used more and more

Future

Future

• OS with every service as container (Rancher OS)
• Windows Containers & Linux Containers on Windows
• Open Container Initiative
• maybe not "Docker" anymore