Terraform Pull Request Automation using Gitlab pipelines

GitLab pipelines provide an effective way to automate development workflows, including the management of Terraform pull requests. A pull request allows contributors to propose and review changes in a Git-based code repository, such as GitLab. To automate Terraform pull requests using GitLab pipelines, several steps must be followed: checking out the pull request branch, initializing Terraform, planning and validating Terraform changes, commenting on the pull request with the Terraform plan, and finally applying the changes. Each of these tasks is performed sequentially within a pipeline defined by a YAML file, which is stored in the GitLab repository. The process involves using various Terraform commands like `init`, `plan`, `validate`, and `apply`, alongside GitLab's API to automate interactions with pull requests, ensuring an efficient, error-free deployment process.