Is it possible to install third-party plugins using terraform init?

The assertion that it is not possible to install third-party plugins using the terraform init command is accurate. In Terraform, the terraform init command is primarily designed to prepare a working directory for other Terraform commands. This preparation includes initializing backend configurations, installing provider plugins defined in the configuration files, and ensuring that the environment is set up correctly to run Terraform.

While it is true that terraform init can download and install provider plugins, it will only install those that are defined in the configuration files specified within the Terraform project. Third-party plugins that are not officially supported or not referenced in the configuration will not be automatically installed. Instead, any additional or custom providers would need to be managed through specific declarations in the Terraform configuration files or by including them in the correct sources.

Thus, standard practice leverages the official Terraform Registry for provider plugins, which means the user relies on terraform init to manage those providers. The ability to manage and install third-party plugins without explicit declarations diverges from Terraform's design philosophy, which emphasizes controlled dependencies and configurations.