Basic Info

WHY ?

Current Infra

Docker Swarm as the orchestration engine

Pros:

• Solves lots of issues, like container lifetime and ease of deployment(up to a point)
• Simple to setup
• Less complicated (comparatively)

Cons:

• Ops at scale is hard ( like swarm reset, network issues)
• At scale it doesn't have the knobs to control the infra nuances unto our liking
• Autoscaling or other cloud-native goodies are absent
• No way to get realtime telemetry or metrics about the state of infra (especially service communication)
• No platforms like knative or istio, which is an instant value add-on for both/infra and addon

Container Fundamentals

• VM vs Container

• Key concepts of container
  • Containers are applications which is restricted by kernel feature called namespaces
    • pid - Process Namespace
    • net - Network
    • mnt - FileSystem
    • usr - UserID
    • utc - hostname
    • ipc - semaphores, channels
  • Cgroups will limit the resource usage
    • ResouceUsage
      • Memory
      • CPU
      • Block I/O
      • Network
    • Device Node access control
      • /dev/*

• Docker is an engine which makes such containers. There are alternatives like containerd, rkt etc