The Importance of Manual Testing in Terraform

Why "It Works" Isn't Enough Until You Prove It Day 17 of the 30-Day Terraform Challenge — and today I learned that my infrastructure "worked" until I actually tested it. I had a webserver cluster. Terraform applied without errors. Everything looked perfect in the AWS Console. I was confident. Then I ran a structured manual test. The results were humbling. The Problem: Code Success ≠ Functional Success Terraform told me: ✅ 11 resources created ✅ No errors ✅ State matches configuration But when I actually tried to use my infrastructure: $ curl http://my-alb-dns 502 Bad Gateway The code worked. The infrastructure didn't. This is why manual testing matters. My Test Checklist I built a structured test plan covering five categories: 1. Provisioning Verification terraform init completes without errors terraform validate passes cleanly terraform plan shows expected resources terraform apply completes successfully 2. Resource Correctness Resources visible in AWS Console Names match variables Ta