Competencies: Infrastructure > Containers

Container Fundamentals

OCI specification, namespaces, cgroups, overlay filesystems, container vs VM, runtime isolation.

Critical

DevOps, SRE, Platform Engineer

Docker

Docker CLI, Dockerfile, images, containers, volumes, networks, docker-compose, Docker Desktop.

Critical

Developer, DevOps, SRE

Podman

Daemonless containers, rootless mode, pod concept, systemd integration, docker compatibility, Quadlet.

High

DevOps, SRE, Linux Administrator

Container Images

Base images, multi-stage builds, layer optimization, scratch images, distroless, image scanning.

High

DevOps, Developer, Security

Container Registries

Docker Hub, Harbor, Quay, ECR/ACR/GCR, image distribution, registry security, image signing.

High

DevOps, Platform Engineer

Buildah/Skopeo

OCI image building, image inspection, copying between registries, scripted image creation.

Medium

DevOps, SRE

Container Networking

Bridge networks, host networking, overlay networks, CNI plugins, service discovery, DNS.

High

DevOps, Network Engineer

Container Storage

Volumes, bind mounts, tmpfs, volume drivers, persistent storage, stateful containers.

High

DevOps, Storage Engineer

Container Security

Rootless containers, seccomp, capabilities, read-only root, user namespaces, pod security.

High

DevSecOps, Security Engineer

docker-compose / Compose

Multi-container applications, YAML syntax, service dependencies, environment variables, profiles.

High

Developer, DevOps

Container Orchestration

Intermediate

Docker and Podman for development containers; docker-compose for multi-service stacks; understand OCI images, registries, layer caching

Container Operations Reference

No buildah/skopeo advanced workflows, no container runtime debugging