Why should secrets not be hard coded into Terraform code?

Hard coding secrets into Terraform code poses significant risks, particularly regarding security and maintainability. One of the major reasons for avoiding hard-coded secrets is that Terraform code is typically stored in version control systems like Git. When secrets are hard coded, they become part of the source code that may be exposed to anyone with access to the repository. This exposure can lead to unauthorized access and potential data breaches, as sensitive information such as API keys, passwords, and other confidential data will inadvertently be shared with anyone who has access to the repository history.

Additionally, using version control means that any changes to the code, including alterations of hard-coded secrets, are tracked over time. This poses a security challenge because the history will contain these sensitive details unless they are properly managed and removed. Best practices recommend using parameters or environment variables to handle sensitive information, which keeps the secrets out of the codebase and reduces the risk of exposure.

Moreover, Terraform has built-in mechanisms to manage sensitive data, such as the ability to mark variables as sensitive and integration with secret management solutions, which allows for safer handling of sensitive information.