api: YAML JSON TOON Database
version: 1.0.0
format: toon
dataset:
  id: 2759
  slug: containerization
  title: Containerization Concepts
  description: Key concepts and terminology in containerization and container orchestration.
  summary: "The concepts behind containers: images, runtimes, registries, orchestration and service meshes, with the Linux kernel features and open standards underneath them, namely namespaces, cgroups, layered file systems and the OCI specifications, and the tool commonly associated with each."
  use_when[2]: You are explaining how containers differ from virtual machines.,"You need to name the kernel feature or tool responsible for isolation, resource limits or packaging."
  caveats[2]: "Containers share the host kernel. Namespaces and cgroups isolate and limit, but a kernel flaw affects every container on the host.","'Docker' is both a company, a tool and a format; the OCI standards let other runtimes use the same images."
  related[3]: container-orchestration,virtualization-concepts,cloud-service-models
  entry_count: 14
  fields[3]{section,field,type,example}:
    data,concept,string,Container Image
    data,description,string,"Immutable, layered filesystem containing applic…"
    data,tool,string,"Dockerfile, BuildKit"
  category: Cloud Computing
  category_slug: cloud-computing
  tags: "cloud,containers,docker,kubernetes,devops"
  view_count: 39
  created_at: 1793403093
  updated_at: 1793403093
data[14]{concept,description,tool}:
  Container Image,"Immutable, layered filesystem containing application code, runtime, and dependencies.","Dockerfile, BuildKit"
  Container Runtime,Software that runs and manages containers.,"containerd, runc, CRI-O"
  Container Registry,Storage and distribution system for container images.,"Docker Hub, GHCR, ECR, ACR"
  Orchestration,Automated management of container lifecycles across clusters.,"Kubernetes, Docker Swarm, Nomad"
  Service Mesh,Infrastructure layer handling service-to-service communication.,"Istio, Linkerd, Envoy"
  Container Network Interface (CNI),Plugin interface for configuring network connectivity.,"Calico, Flannel, Cilium"
  Persistent Storage,Storage that persists beyond the container lifecycle.,"PersistentVolume, CSI drivers"
  Dockerfile,"A text recipe describing how to build an image, one instruction per layer.","Docker, Podman, BuildKit"
  Layered Filesystem,"Images are stacks of read-only layers with a writable layer on top, so common layers are shared and cached.",OverlayFS
  Namespaces,"Linux kernel feature that gives a process its own view of processes, network, mounts and users.",Linux kernel
  Control Groups,"Linux kernel feature that limits and accounts for CPU, memory and I/O used by a group of processes.",Linux kernel (cgroups)
  Open Container Initiative,Open standards for image format and runtime so images run across compatible tools.,OCI image and runtime specs
  Rootless Containers,Running containers without root privileges on the host to reduce the impact of a breakout.,"Podman, rootless Docker"
  Multi-Stage Build,Using several build stages and copying only the results into the final image to keep it small.,"Docker, BuildKit"