Why Containers

Why Containers

Internals

Namespaces

• Used for resource isolation
• Isolation of resource usage to limit visibility
• Types are PID, network, mount

c(ontrol)groups

• Used to limit resource usage for proceses
• Limits and measures access to…
• …CPU, memory, network, IO

Docker

Packaged

• Includes dependencies
• Distributable

Immutable

• Incremental changes not supported
• Changes require rollout

Automated

• Image builds
• Deployments

Stateless

• By default, no persistence

Is Docker still relevant?

With regard to…

Orchestration

• No, Kubernetes has won

Container runtime

• Often, but containerd is growing quickly

Image build

• Yes
• Other image builders are still niche players
• Examples: buildah, img, kaniko (list not exhaustive)