Immutable Infrastructure
Immutable infrastructure principle: instances are never modified after creation; changes happen by replacing instances, eliminating configuration drift.
Purpose
Eliminate configuration drift and snowflake servers, improving consistency and reproducibility.
Mechanism
Once created, instances cannot be modified via SSH. Changes come from building new images/templates + replacing instances. K8s Pods are immutable; Deployments replace them by rolling. IaC + containerization enable immutability.
Use cases
- Configuration consistency
- Reproducibility
- Simplified operations