Mastering the Art of Fixing Broken Automations: A DevOps Guide

In the fast-paced world of DevOps, automation is king. But what happens when your carefully crafted automation scripts start to falter? Let's dive into a real-world scenario and uncover the secrets to diagnosing and fixing complex automation issues.

The Scenario: A Failing Health Check

Imagine this: You've got a critical health check automation for your cloud infrastructure. It's been running smoothly for months, but suddenly, it starts failing. No errors, just... silence. Sound familiar? Let's break down the approach to tackle this head-on.

1. Start with the Basics: Logging

First things first, enhance your logging. In our case, we added detailed debug logs to our Python script:

logger.debug(f"Request payload: {json.dumps(execute_command_request, indent=2)}")
logger.debug(f"Response content: {response.text}")

This simple addition gave us crucial insights into the API interactions.

2. Isolate the Problem: Divide and Conquer

Break your automation into smaller, testable units. We started by testing a simple command:

cmd = "whoami && id && sudo -n whoami"

This helped us isolate whether the issue was with our specific command or the entire execution framework.

3. Check Your Assumptions

Just because a command is executing doesn't mean it's working as expected. We learned this the hard way when our commands ran successfully but returned no output. Always verify your assumptions!

4. Understand Your Environment

Remote execution adds layers of complexity. In our case, we were dealing with:

• A Python script

• Running in a Jenkins pipeline

• Executing commands on remote AWS instances

• Through an intermediate REX (Remote Execution) service

Each layer is a potential point of failure. Document and understand your entire execution path.

5. Security Matters

When dealing with remote execution, especially involving sudo, security configurations can throw a wrench in your automation. Always check:

• Sudo permissions

• Network security groups

• IAM roles and policies

6. Embrace Asynchronous Thinking

In remote execution scenarios, there's often a delay between command submission and result retrieval. Design your automation to handle this asynchronous nature gracefully.

7. Have a Fallback Plan

Sometimes, you need to get your hands dirty. Consider implementing a direct SSH fallback for debugging purposes. It can be a lifesaver when your main automation path is obscure.

8. Keep It Simple, Smarty (KISS)

As you fix and enhance your automation, resist the urge to over-engineer. Simple, readable code is easier to debug and maintain. Our journey taught us the value of clear, well-commented code in troubleshooting sessions.

Conclusion: The Path Forward

Fixing broken automations is as much an art as it is a science. It requires patience, systematic thinking, and a dash of creativity. Remember, every bug you squash makes your automation more robust and your skills sharper.

By following these steps and keeping a curious, persistent mindset, you'll be well-equipped to tackle even the most perplexing automation challenges. Happy debugging!

What's your go-to strategy for fixing automations? Share your experiences in the comments below!