https://besterry.com/categories/tools/Recent content in Tools on Besterry — Linux & DevOps NotesHugoen-usWed, 18 Sep 2024 00:00:00 +0000https://besterry.com/posts/terraform-state-locking/Wed, 18 Sep 2024 00:00:00 +0000https://besterry.com/posts/terraform-state-locking/<p>Terraform state without locking is a bug waiting to happen. Two engineers running apply simultaneously can corrupt state in ways that take hours to untangle. Here&rsquo;s what I learned after one such incident.</p> <h2 id="why-state-locking-matters">Why state locking matters</h2> <p>Terraform reads state, computes a plan, and writes new state. Without locking, two concurrent runs can:</p> <ul> <li>Both read the same initial state</li> <li>Both compute their plans based on it</li> <li>Both write conflicting state — last one wins</li> <li>Now state doesn&rsquo;t match real infrastructure</li> </ul> <p>The symptoms are weird: resources exist but Terraform wants to create them again. Or state references resources that were already destroyed.</p>