Testing infrastructure changes before applying them prevents costly mistakes in production. Terraform's plan command and HashiCorp Sentinel policies provide a safety net that catches configuration errors and policy violations before any resources are modified.
Leveraging Terraform Plan Effectively
Always review terraform plan output before applying changes. The plan shows exactly which resources will be created, modified, or destroyed. Pay special attention to in-place updates versus destroy-and-recreate actions that could cause downtime.
Sentinel policies enforce governance rules as code. Define policies that prevent deploying instances without encryption, require specific tags on all resources, or restrict which regions and instance types are allowed. Failed policy checks block the apply operation.
Automated plan reviews in CI/CD pipelines catch issues early. Post plan output as pull request comments so team members can review infrastructure changes with the same rigor as application code changes, maintaining infrastructure quality standards.