Testing Infrastructure: Unit, Integration, and End-to-End Tests

Building test pyramids, chaos engineering, and ensuring infrastructure reliability.

Infrastructure code deserves the same test discipline as application code. Untested Terraform is production roulette.

Layers of Testing

Static analysis catches syntax and policy violations. Unit tests validate module logic with mock providers. Integration tests spin ephemeral environments. End-to-end tests verify critical paths in staging before promotion.

Chaos Engineering

Deliberately inject failures: kill nodes, throttle networks, expire certificates. Game days prove your assumptions about resilience. Start in non-production, graduate to controlled production experiments.

CI Integration

Plan on PR, apply on merge to dev, promote with gates. Cost estimation and policy checks are tests too. Failed pipelines block releases.

Reliable infrastructure is tested infrastructure.

CI Pipeline Integration

Run terraform validate and plan on every pull request. Apply only from protected branches. Use separate cloud accounts for CI testing to prevent accidents. Tear down ephemeral environments automatically after tests complete.

Chaos Experiments

Start with controlled experiments: terminate a single node, inject latency, fill disk. Document system behavior. Expand scope as confidence grows. Never run chaos in production without stakeholder approval and rollback plans.

Common Pitfalls

Adopting tools before defining outcomes leads to expensive experiments without business value. Copying another organization's architecture without understanding your constraints creates fragile systems. Skipping documentation means every new team member relearns lessons the hard way.

Getting Started

Define success metrics before implementation. Start with the smallest scope that proves value. Review results with stakeholders weekly during the first month. Iterate based on evidence, not assumptions.