What is CloudTrail?

CloudTrail is an Amazon Web Services (AWS) feature that automatically records every action taken in your AWS account, like who did what and when. It stores these records (called events) in log files so you can look back later.

Let's break it down

  • Amazon Web Services (AWS): A collection of online tools (like storage, servers, databases) that companies use instead of their own hardware.
  • Feature: A specific tool or capability inside a larger service.
  • Records every action: Writes down each command or change, such as launching a server or deleting a file.
  • In your AWS account: The personal “space” where all your AWS resources live.
  • Log files: Text files that list the details of each action (who, what, when, where).
  • Look back later: You can search the logs to see past activity, like a security camera’s footage.

Why does it matter?

CloudTrail gives you visibility into who is using your cloud resources, helping you spot mistakes, unauthorized access, or security breaches. It also helps meet compliance rules that require you to keep a record of all activity.

Where is it used?

  • Security investigations: After a suspicious login, you can trace the exact steps the attacker took.
  • Compliance reporting: Companies in regulated industries (finance, healthcare) use CloudTrail logs to prove they follow legal standards.
  • Operational troubleshooting: If a server stops working, you can check the logs to see if a recent change caused the issue.
  • Cost management: By reviewing who launched expensive resources, you can control unexpected spending.

Good things about it

  • Automatic, continuous logging - no manual setup needed after enabling.
  • Centralized storage in Amazon S3, making logs easy to keep long-term and query.
  • Integration with other AWS tools (e.g., CloudWatch, Athena) for alerts and analysis.
  • Supports multi-region and multi-account setups, giving a complete view across your whole environment.
  • Helps meet many industry compliance standards out of the box.

Not-so-good things

  • Generates a large volume of data, which can become costly to store and process if not managed.
  • Raw log files are verbose; extracting useful information often requires extra tools or scripting.
  • Some AWS services have limited or delayed logging, so not every action is captured instantly.
  • Requires proper IAM permissions and bucket policies; misconfiguration can expose logs to unauthorized users.