Lambda Chaos Testing Blocked: Waiting For Terraform Fix

Hey guys, we've hit a snag with our Lambda FIS chaos testing, and I wanted to give you the lowdown. Basically, we're currently blocked due to a pesky bug in the Terraform AWS provider. This means we can't fully leverage the new Lambda fault injection features that AWS rolled out. Let's dive into the details, the workaround, and what we'll do once the fix is in place. This whole situation revolves around making our systems more resilient, and chaos testing is a crucial part of that.

The Root of the Problem: Terraform Provider Woes

So, the issue stems from a validation problem within the Terraform AWS provider. Specifically, the provider doesn't recognize "Functions" as a valid target key for Lambda fault injection actions. This is a real bummer because it prevents us from using cool new features like injecting latency (aws:lambda:invocation-add-delay) and forcing errors (aws:lambda:invocation-error) into our Lambda functions. These actions are super important in chaos testing to simulate real-world failures and ensure our systems can handle them gracefully. The core problem lies within our Terraform configuration files, specifically in infrastructure/terraform/main.tf (lines 442-445) and modules/chaos/main.tf. The issue is documented on GitHub (hashicorp/terraform-provider-aws#41208), where the community is actively tracking the provider's bug. The AWS FIS (Fault Injection Service) team added these Lambda fault injection actions back in October 2024. These updates were designed to make testing Lambda functions much more robust. Now, we are held back until this is resolved. Until then, we are stuck with a blocked status, waiting for the Terraform provider to catch up.

This delay not only impacts our ability to perform comprehensive chaos testing but also hinders our efforts to build more reliable and resilient systems. However, we're not just twiddling our thumbs; we've implemented a workaround to keep things moving. The goal is to ensure that our applications are resilient enough to handle unexpected issues, which is why chaos testing is so critical. We want to simulate how our applications would behave when real problems happen. This way, we can make sure our systems are robust and keep working even during trouble.

Current Workaround: Staying Safe for Now

To keep our systems safe and stable while we wait for the Terraform fix, we've implemented a simple workaround. In main.tf, we've set enable_chaos_testing = false. This disables the chaos testing functionality, preventing us from running into the provider's validation bug. Basically, this means we've temporarily paused our ability to inject faults into Lambda functions. This is not ideal, as it limits our ability to test for failures, but it's a necessary precaution to avoid breaking our infrastructure during deployment. It's a bit like putting a temporary block on the gas pedal; we can't go full speed, but we're also not at risk of crashing. This workaround is essential for maintaining the stability of our infrastructure while we wait for the provider to be updated. It allows us to continue with other development tasks without risking disruptions caused by the Terraform bug.

This also allows us to focus on other development tasks and features. This workaround allows us to maintain a stable environment and continue with other critical tasks. While this workaround keeps things stable, it is not ideal. We really want to use the fault injection features to make sure everything will work as planned, even when things go wrong. While it's a temporary measure, it’s a necessary step to keep our pre-production environment stable. The main idea is to keep things from breaking until we can get the real fix in place.

Resolution Steps: When the Provider Gets Fixed

Once the Terraform provider gets updated, here's what we'll do to re-enable and leverage those awesome chaos testing features. First, we need to update the AWS provider version in versions.tf. This ensures we're using the latest version with the bug fix. The goal is to quickly apply the fixes and re-enable chaos testing in our pre-production environment. Next, we'll change enable_chaos_testing = false to var.environment == "preprod" in main.tf. This means we'll only enable chaos testing in our pre-production environment. And finally, we'll thoroughly test the chaos experiments in preprod. We'll verify that the Lambda fault injection actions are working as expected and that our systems are responding correctly to the injected faults. This is where we'll ensure that everything works as expected.

We will need to thoroughly test the changes in the preprod environment. We'll need to confirm that our systems react correctly when faults are injected. This step is super important to confirm everything is working correctly and that there aren't any surprises. With the fix in place and testing complete, we'll be able to confidently resume our chaos testing efforts. This will allow us to ensure our systems are resilient and can withstand failures. The goal is to make sure our systems can handle unexpected problems and that we're providing the best experience possible for our users.

Effort and Status: Time and Current State

The good news is that once the provider is updated, the fix is expected to take only about 30 minutes. This includes updating the Terraform configuration, testing the changes, and verifying that the chaos experiments are working. Our current status is BLOCKED, as we are waiting for the upstream issue to be resolved. This means we're actively monitoring the progress of the bug fix in the Terraform AWS provider. We are constantly checking for updates and will start the resolution steps as soon as the fix is released. This means that we cannot move forward until the fix has been implemented in the Terraform provider. The team is on standby, ready to jump on the resolution steps as soon as the fix is released. We are now in a holding pattern, waiting for the provider update. As soon as the fix is available, we'll jump on it and quickly re-enable our chaos testing capabilities. This will allow us to ensure our systems remain robust. We will closely watch the progress and take action as soon as the fix is ready. This is a temporary setback, and we're eager to get back to full-fledged chaos testing.

Labels: Key Tags

To keep things organized, this issue is tagged with the following labels: blocked, infrastructure, and chaos-testing. These labels help us categorize the issue. This allows us to quickly identify and track related problems and keep our team informed. We use these labels to manage our projects, track progress, and communicate effectively within the team. This helps with tracking and makes sure that everyone on the team is aware of the current status and priority of the issue. These labels will help ensure that all team members are on the same page and aware of the issue's priority and progress.