constellation/docs/versioned_docs/version-2.16/workflows/config.md

Configure your cluster

:::info This recording presents the essence of this page. It's recommended to read it in full for the motivation and all details. :::

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Before you can create your cluster, you need to configure the identity and access management (IAM) for your cloud service provider (CSP) and choose machine types for the nodes.

Creating the configuration file

You can generate a configuration file for your CSP by using the following CLI command:

constellation config generate aws

constellation config generate azure

constellation config generate gcp

constellation config generate stackit

This creates the file constellation-conf.yaml in the current directory.

Choosing a VM type

Constellation supports the following VM types:

By default, Constellation uses m6a.xlarge VMs (4 vCPUs, 16 GB RAM) to create your cluster. Optionally, you can switch to a different VM type by modifying instanceType in the configuration file. If you are using the default attestation variant awsSEVSNP, you can use the instance types described in AWS's AMD SEV-SNP docs. Please mind the region restrictions mentioned in the Getting started section.

If you are using the attestation variant awsNitroTPM, you can choose any of the nitroTPM-enabled instance types.

The Constellation CLI can also print the supported instance types with: constellation config instance-types.

By default, Constellation uses Standard_DC4as_v5 CVMs (4 vCPUs, 16 GB RAM) to create your cluster. Optionally, you can switch to a different VM type by modifying instanceType in the configuration file. For CVMs, any VM type with a minimum of 4 vCPUs from the DCasv5 & DCadsv5 or ECasv5 & ECadsv5 families is supported.

You can also run constellation config instance-types to get the list of all supported options.

By default, Constellation uses n2d-standard-4 VMs (4 vCPUs, 16 GB RAM) to create your cluster. Optionally, you can switch to a different VM type by modifying instanceType in the configuration file. Supported are all machines with a minimum of 4 vCPUs from the C2D or N2D family. You can run constellation config instance-types to get the list of all supported options.

By default, Constellation uses m1a.4cd VMs (4 vCPUs, 30 GB RAM) to create your cluster. Optionally, you can switch to a different VM type by modifying instanceType in the configuration file.

The following instance types are known to be supported:

name	vCPUs	GB RAM
m1a.4cd	4	30
m1a.8cd	8	60
m1a.16cd	16	120
m1a.30cd	30	230

You can choose any of the SEV-enabled instance types. You can find a list of all supported instance types in the STACKIT documentation.

The Constellation CLI can also print the supported instance types with: constellation config instance-types.

Fill the desired VM type into the instanceType fields in the constellation-conf.yml file.

Creating additional node groups

By default, Constellation creates the node groups control_plane_default and worker_default for control-plane nodes and workers, respectively. If you require additional control-plane or worker groups with different instance types, zone placements, or disk sizes, you can add additional node groups to the constellation-conf.yml file. Each node group can be scaled individually.

Consider the following example for AWS:

nodeGroups:
  control_plane_default:
    role: control-plane
    instanceType: c6a.xlarge
    stateDiskSizeGB: 30
    stateDiskType: gp3
    zone: eu-west-1c
    initialCount: 3
  worker_default:
    role: worker
    instanceType: c6a.xlarge
    stateDiskSizeGB: 30
    stateDiskType: gp3
    zone: eu-west-1c
    initialCount: 2
  high_cpu:
    role: worker
    instanceType: c6a.24xlarge
    stateDiskSizeGB: 128
    stateDiskType: gp3
    zone: eu-west-1c
    initialCount: 1

This configuration creates an additional node group high_cpu with a larger instance type and disk.

You can use the field zone to specify what availability zone nodes of the group are placed in. On Azure, this field is empty by default and nodes are automatically spread across availability zones. STACKIT currently offers SEV-enabled CPUs in the eu01-1, eu01-2, and eu01-3 zones. Consult the documentation of your cloud provider for more information:

• AWS
• Azure
• GCP
• STACKIT

Choosing a Kubernetes version

To learn which Kubernetes versions can be installed with your current CLI, you can run constellation config kubernetes-versions. See also Constellation's Kubernetes support policy.

Creating an IAM configuration

You can create an IAM configuration for your cluster automatically using the constellation iam create command. If you already have a Constellation configuration file, you can add the --update-config flag to the command. This writes the needed IAM fields into your configuration. Furthermore, the flag updates the zone/region of the configuration if it hasn't been set yet.

You must be authenticated with the AWS CLI in the shell session with a user that has the required permissions for IAM creation.

constellation iam create aws --zone=us-east-2a --prefix=constellTest

This command creates IAM configuration for the AWS zone us-east-2a using the prefix constellTest for all named resources being created.

Constellation OS images are currently replicated to the following regions:

• eu-central-1
• eu-west-1
• eu-west-3
• us-east-2
• ap-south-1

If you require the OS image to be available in another region, let us know.

You can find a list of all regions in AWS's documentation.

Paste the output into the corresponding fields of the constellation-conf.yaml file.

You must be authenticated with the Azure CLI in the shell session with a user that has the required permissions for IAM creation.

constellation iam create azure --region=westus --resourceGroup=constellTest --servicePrincipal=spTest

This command creates IAM configuration on the Azure region westus creating a new resource group constellTest and a new service principal spTest.

CVMs are available in several Azure regions. Constellation OS images are currently replicated to the following:

• germanywestcentral
• westus
• eastus
• northeurope
• westeurope
• southeastasia

If you require the OS image to be available in another region, let us know.

You can find a list of all regions in Azure's documentation.

Paste the output into the corresponding fields of the constellation-conf.yaml file.

You must be authenticated with the GCP CLI in the shell session with a user that has the required permissions for IAM creation.

constellation iam create gcp --projectID=yourproject-12345 --zone=europe-west2-a --serviceAccountID=constell-test

This command creates IAM configuration in the GCP project yourproject-12345 on the GCP zone europe-west2-a creating a new service account constell-test.

Note that only regions offering CVMs of the C2D or N2D series are supported. You can find a list of all regions in Google's documentation, which you can filter by machine type N2D.

Paste the output into the corresponding fields of the constellation-conf.yaml file.

STACKIT requires manual creation and configuration of service accounts. Look at the first steps for more information.

Alternatively, you can manually create the IAM configuration on your CSP.

The following describes the configuration fields and how you obtain the required information or create the required resources.

• region: The name of your chosen AWS data center region, e.g., us-east-2.

  Constellation OS images are currently replicated to the following regions:

  • eu-central-1
  • eu-west-1
  • eu-west-3
  • us-east-2
  • ap-south-1

  If you require the OS image to be available in another region, let us know.

  You can find a list of all regions in AWS's documentation.

• zone: The name of your chosen AWS data center availability zone, e.g., us-east-2a.

  Learn more about availability zones in AWS's documentation.

• iamProfileControlPlane: The name of an IAM instance profile attached to all control-plane nodes.

  You can create the resource with Terraform. For that, use the provided Terraform script to generate the necessary profile. The profile name will be provided as Terraform output value: control_plane_instance_profile_name.

  Alternatively, you can create the AWS profile with a tool of your choice. Use the JSON policy in main.tf in the resource aws_iam_policy.control_plane_policy.

• iamProfileWorkerNodes: The name of an IAM instance profile attached to all worker nodes.

  You can create the resource with Terraform. For that, use the provided Terraform script to generate the necessary profile. The profile name will be provided as Terraform output value: worker_nodes_instance_profile_name.

  Alternatively, you can create the AWS profile with a tool of your choice. Use the JSON policy in main.tf in the resource aws_iam_policy.worker_node_policy.

• subscription: The UUID of your Azure subscription, e.g., 8b8bd01f-efd9-4113-9bd1-c82137c32da7.

  You can view your subscription UUID via az account show and read the id field. For more information refer to Azure's documentation.

• tenant: The UUID of your Azure tenant, e.g., 3400e5a2-8fe2-492a-886c-38cb66170f25.

  You can view your tenant UUID via az account show and read the tenant field. For more information refer to Azure's documentation.

• location: The Azure datacenter location you want to deploy your cluster in, e.g., westus.

  CVMs are available in several Azure regions. Constellation OS images are currently replicated to the following:

  • germanywestcentral
  • westus
  • eastus
  • northeurope
  • westeurope
  • southeastasia

  If you require the OS image to be available in another region, let us know.

  You can find a list of all regions in Azure's documentation.

• resourceGroup: Create a new resource group in Azure for your Constellation cluster. Set this configuration field to the name of the created resource group.

• userAssignedIdentity: Create a new managed identity in Azure. You should create the identity in a different resource group as all resources within the cluster resource group will be deleted on cluster termination.

  Add three role assignments to the identity: Owner, Virtual Machine Contributor, and Application Insights Component Contributor. The scope of all three should refer to the previously created cluster resource group.

  Set the configuration value to the full ID of the created identity, e.g., /subscriptions/8b8bd01f-efd9-4113-9bd1-c82137c32da7/resourcegroups/constellation-identity/providers/Microsoft.ManagedIdentity/userAssignedIdentities/constellation-identity. You can get it by opening the JSON View from the Overview section of the identity.

  The user-assigned identity is used by instances of the cluster to access other cloud resources. For more information about managed identities refer to Azure's documentation.

• project: The ID of your GCP project, e.g., constellation-129857.

  You can find it on the welcome screen of your GCP project. For more information refer to Google's documentation.

• region: The GCP region you want to deploy your cluster in, e.g., us-west1.

  You can find a list of all regions in Google's documentation.

• zone: The GCP zone you want to deploy your cluster in, e.g., us-west1-a.

  You can find a list of all zones in Google's documentation.

• serviceAccountKeyPath: To configure this, you need to create a GCP service account with the following permissions:

  • Compute Instance Admin (v1) (roles/compute.instanceAdmin.v1)
  • Compute Network Admin (roles/compute.networkAdmin)
  • Compute Security Admin (roles/compute.securityAdmin)
  • Compute Storage Admin (roles/compute.storageAdmin)
  • Service Account User (roles/iam.serviceAccountUser)

  Afterward, create and download a new JSON key for this service account. Place the downloaded file in your Constellation workspace, and set the config parameter to the filename, e.g., constellation-129857-15343dba46cb.json.

STACKIT requires manual creation and configuration of service accounts. Look at the first steps for more information.

Now that you've configured your CSP, you can create your cluster.

Deleting an IAM configuration

You can keep a created IAM configuration and reuse it for new clusters. Alternatively, you can also delete it if you don't want to use it anymore.

Delete the IAM configuration by executing the following command in the same directory where you executed constellation iam create (the directory that contains constellation-iam-terraform as a subdirectory):

constellation iam destroy

:::caution For Azure, deleting the IAM configuration by executing constellation iam destroy will delete the whole resource group created by constellation iam create. This also includes any additional resources in the resource group that weren't created by Constellation. :::