Container Orchestration

A. Containers¶

isolated environment : physical machine > VM > Containers(host OS)
Containers are similar to VMs, but share the Operating System (OS) among the applications.
Therefore, containers are considered lightweight.
Similar to a VM, a container has its own filesystem, share of CPU, memory, process space, and more.
As they are decoupled from the underlying infrastructure, they are portable across clouds and OS distributions.

eg: Docker image
image built on OS-1 as base, can be run my machine having window OS. docker desktop in between.
best suited for microservices/MS by providing portability and isolated VM
executable package, which confine the code,runtime and dependencies, env var+configFile in a pre-defined format.
Composed of multiple layers, stacked on top of a base image.
Images are stored in repositories, which can be public or private. eg : Docker Hub, ECR
versioned using tags
Security:
- Use trusted base-images
- identify vulnerabilities in images and upgrade it. docker has built in scanner.
- regularly update images to include security patches.

framework for managing containers at scale at runtime
For Distributed-System (ms), provides deployment patterns of container.
automate the deployment
- release - rollout / rollback
scale
service discovery + networking
storage
config + secrets
orchestrators make things easier, when managing hundreds or thousands of containers.
offerings:
Docker Swarm (native)
Kubernetes/k8s - minikube, EKS, AKS
AWS - ECS
marathon