How do you manage artifacts in CI/CD? Why are versioning strategy and immutable artifacts important?

Artifact Management

An artifact is the output of a build process: Docker images, JAR files, NPM packages, etc.

Immutable Artifacts

Core principle: The same version of an artifact has identical content across all environments and is never modified.

Benefits:

• An image that passes tests in dev is guaranteed to be the same one deployed to prod
• Problems can be accurately reproduced in the production environment
• Clear audit trail

Anti-patterns that violate this principle: using the :latest tag, or rebuilding in different environments.

Docker Image Versioning Strategies

Semantic versioning: v1.2.3 (suitable for public APIs)

Git commit SHA: myapp:abc1234 (recommended — most precise, fully traceable)

Build number: myapp:build-456 (used with CI system)

Multi-tag strategy (recommended):

Tag the same image with multiple tags simultaneously:

• myapp:abc1234 (immutable, points to specific commit)
• myapp:v1.2.3 (semantic version)
• myapp:latest (points to latest stable, convenient for development)

Container Registries

Platform	Registry
AWS	ECR (Elastic Container Registry)
GCP	Artifact Registry
Azure	ACR (Azure Container Registry)
General	Docker Hub, GitHub Container Registry

Cleanup Policy

Set image retention policies to automatically delete images older than N days or beyond N versions, controlling storage costs.