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Docker for Repeatable Services

A production-minded model for images, containers, layers, networks, and local environments.

DockerDevOpsContainers
DOMAIN
DevOps
LEVEL
Foundational
READ
7 min
UPDATED
Aug 1, 2026

MENTAL MODEL / KEY IDEAS

Keep these in mind

  1. 01An image is an immutable build result
  2. 02Runtime state stays outside the image
  3. 03Reproducibility requires pinned inputs
01

Image and container

The image packages the filesystem and process configuration. A container is a runtime instance with its own writable layer and resource boundaries.

  • Layer cache
  • Entrypoint
  • Volumes
  • Networks
02

Build well

Small build contexts, multi-stage images, locked dependencies, and non-root runtime users improve speed and safety.

  • Pin base images
  • Copy dependency files first
  • Exclude secrets
03

Operate predictably

Health signals, graceful shutdown, and explicit configuration make the same image useful from local development to deployment.