constellation/docs/versioned_docs/version-2.19/workflows/terraform-provider.md

# Use the Terraform provider

The Constellation Terraform provider allows to manage the full lifecycle of a Constellation cluster (namely creation, upgrades, and deletion) via Terraform.
The provider is available through the [Terraform registry](https://registry.terraform.io/providers/edgelesssys/constellation/latest) and is released in lock-step with Constellation releases.

## Prerequisites

- a Linux / Mac operating system (ARM64/AMD64)
- a Terraform installation of version `v1.4.4` or above

## Quick setup

This example shows how to set up a Constellation cluster with the reference IAM and infrastructure setup. This setup is also used when creating a Constellation cluster through the Constellation CLI. You can either consume the IAM / infrastructure modules through a remote source (recommended) or local files. The latter requires downloading the infrastructure and IAM modules for the corresponding CSP from `terraform-modules.zip` on the [Constellation release page](https://github.com/edgelesssys/constellation/releases/latest) and placing them in the Terraform workspace directory.

1. Create a directory (workspace) for your Constellation cluster.

  ```bash
  mkdir constellation-workspace
  cd constellation-workspace
  ```

2. Use one of the [example configurations for using the Constellation Terraform provider](https://github.com/edgelesssys/constellation/tree/main/terraform-provider-constellation/examples/full) or create a `main.tf` file and fill it with the resources you want to create. The [Constellation Terraform provider documentation](https://registry.terraform.io/providers/edgelesssys/constellation/latest) offers thorough documentation on the resources and their attributes.
3. Initialize and apply the Terraform configuration.
  <Tabs groupId="csp">

  <TabItem value="aws" label="AWS">
  Initialize the providers and apply the configuration.

  ```bash
  terraform init
  terraform apply
  ```

  Optionally, you can prefix the `terraform apply` command with `TF_LOG=INFO` to collect [Terraform logs](https://developer.hashicorp.com/terraform/internals/debugging) while applying the configuration. This may provide helpful output in debugging scenarios.
  </TabItem>
  <TabItem value="azure" label="Azure">

:::info
On SEV-SNP, you need to manually patch the policy of the MAA provider before creating the Constellation cluster, as this feature isn't available in Azure's Terraform provider yet. The Constellation CLI provides a utility for patching, but you can also do it manually.

  ```bash
  terraform init
  terraform apply -target module.azure_iam # adjust resource path if not using the example configuration
  terraform apply -target module.azure_infrastructure # adjust resource path if not using the example configuration
  constellation maa-patch $(terraform output -raw maa_url) # adjust output path / input if not using the example configuration or manually patch the resource
  terraform apply -target constellation_cluster.azure_example # adjust resource path if not using the example configuration
  ```

    Use the following policy if manually performing the patch.

  ```
  version= 1.0;
  authorizationrules
  {
      [type=="x-ms-azurevm-default-securebootkeysvalidated", value==false] => deny();
      [type=="x-ms-azurevm-debuggersdisabled", value==false] => deny();
      // The line below was edited to use the MAA provider within Constellation. Do not edit manually.
      //[type=="secureboot", value==false] => deny();
      [type=="x-ms-azurevm-signingdisabled", value==false] => deny();
      [type=="x-ms-azurevm-dbvalidated", value==false] => deny();
      [type=="x-ms-azurevm-dbxvalidated", value==false] => deny();
      => permit();
  };
  issuancerules
  {
  };
  ```

:::

    Initialize the providers and apply the configuration.

  ```bash
  terraform init
  terraform apply
  ```

  Optionally, you can prefix the `terraform apply` command with `TF_LOG=INFO` to collect [Terraform logs](https://developer.hashicorp.com/terraform/internals/debugging) while applying the configuration. This may provide helpful output in debugging scenarios.

  </TabItem>

  <TabItem value="gcp" label="GCP">
  Initialize the providers and apply the configuration.

  ```bash
  terraform init
  terraform apply
  ```

  Optionally, you can prefix the `terraform apply` command with `TF_LOG=INFO` to collect [Terraform logs](https://developer.hashicorp.com/terraform/internals/debugging) while applying the configuration. This may provide helpful output in debugging scenarios.
  </TabItem>
  <TabItem value="stackit" label="STACKIT">
  Initialize the providers and apply the configuration.

  ```bash
  terraform init
  terraform apply
  ```

  Optionally, you can prefix the `terraform apply` command with `TF_LOG=INFO` to collect [Terraform logs](https://developer.hashicorp.com/terraform/internals/debugging) while applying the configuration. This may provide helpful output in debugging scenarios.
  </TabItem>

  </Tabs>
4. Connect to the cluster.

  ```bash
  terraform output -raw kubeconfig > constellation-admin.conf
  export KUBECONFIG=$(realpath constellation-admin.conf)
  ```

## Bringing your own infrastructure

Instead of using the example infrastructure used in the [quick setup](#quick-setup), you can also provide your own infrastructure.
If you need a starting point for a custom infrastructure setup, you can download the infrastructure / IAM Terraform modules for the respective CSP from the Constellation [GitHub releases](https://github.com/edgelesssys/constellation/releases). You can modify and extend the modules per your requirements, while keeping the basic functionality intact.
The module contains:

- `{csp}`: cloud resources the cluster runs on
- `iam/{csp}`: IAM resources used within the cluster

When upgrading your cluster, make sure to check the Constellation release notes for potential breaking changes in the reference infrastructure / IAM modules that need to be considered.

## Cluster upgrades

:::tip
Also see the [general documentation on cluster upgrades](./upgrade.md).
:::

The steps for applying the upgrade are as follows:

1. Update the version constraint of the Constellation Terraform provider in the `required_providers` block in your Terraform configuration.
2. If you explicitly set any of the version attributes of the provider's resources and data sources (e.g. `image_version` or `constellation_microservice_version`), make sure to update them too. Refer to Constellation's [version support policy](https://github.com/edgelesssys/constellation/blob/main/dev-docs/workflows/versions-support.md) for more information on how each Constellation version and its dependencies are supported.
3. Update the IAM / infrastructure configuration.
   - For [remote addresses as module sources](https://developer.hashicorp.com/terraform/language/modules/sources#fetching-archives-over-http), update the version number inside the address of the `source` field of the infrastructure / IAM module to the target version.
   - For [local paths as module sources](https://developer.hashicorp.com/terraform/language/modules/sources#local-paths) or when [providing your own infrastructure](#bringing-your-own-infrastructure), see the changes made in the reference modules since the upgrade's origin version and adjust your infrastructure / IAM configuration accordingly.
4. Upgrade the Terraform module and provider dependencies and apply the targeted configuration.

```bash
  terraform init -upgrade
  terraform apply
```