Component: `eks/karpenter`

This component provisions Karpenter on an EKS cluster. It requires at least version 0.19.0 of Karpenter, though you are encouraged to use the latest version.

Usage

Stack Level: Regional

These instructions assume you are provisioning 2 EKS clusters in the same account and region, named "blue" and "green", and alternating between them. If you are only using a single cluster, you can ignore the "blue" and "green" references and remove the metadata block from the karpenter module.

components:
  terraform:

    # Base component of all `karpenter` components
    eks/karpenter:
      metadata:
        type: abstract
      settings:
        spacelift:
          workspace_enabled: true
      vars:
        enabled: true
        tags:
          Team: sre
          Service: karpenter
        eks_component_name: eks/cluster
        name: "karpenter"
        chart: "karpenter"
        chart_repository: "https://charts.karpenter.sh"
        chart_version: "v0.16.3"
        create_namespace: true
        kubernetes_namespace: "karpenter"
        resources:
          limits:
            cpu: "300m"
            memory: "1Gi"
          requests:
            cpu: "100m"
            memory: "512Mi"
        cleanup_on_fail: true
        atomic: true
        wait: true
        rbac_enabled: true
        # Set `legacy_create_karpenter_instance_profile` to `false` to allow the `eks/cluster` component
        # to manage the instance profile for the nodes launched by Karpenter (recommended for all new clusters).
        legacy_create_karpenter_instance_profile: false

    # Provision `karpenter` component on the blue EKS cluster
    eks/karpenter-blue:
      metadata:
        component: eks/karpenter
        inherits:
          - eks/karpenter
      vars:
        eks_component_name: eks/cluster-blue

Provision Karpenter on EKS cluster

Here we describe how to provision Karpenter on an EKS cluster. We will be using the plat-ue2-dev stack as an example.

Provision Service-Linked Roles for EC2 Spot and EC2 Spot Fleet

Note: If you want to use EC2 Spot for the instances launched by Karpenter, you may need to provision the following Service-Linked Role for EC2 Spot:

Service-Linked Role for EC2 Spot

This is only necessary if this is the first time you're using EC2 Spot in the account. Since this is a one-time operation, we recommend you do this manually via the AWS CLI:

aws --profile <namespace>-<tenamt>-gbl-<stage>-admin iam create-service-linked-role --aws-service-name spot.amazonaws.com

Note that if the Service-Linked Roles already exist in the AWS account (if you used EC2 Spot or Spot Fleet before), and you try to provision them again, you will see the following errors:

An error occurred (InvalidInput) when calling the CreateServiceLinkedRole operation:
Service role name AWSServiceRoleForEC2Spot has been taken in this account, please try a different suffix

For more details, see:

The process of provisioning Karpenter on an EKS cluster consists of 3 steps.

1. Provision EKS Fargate Profile for Karpenter and IAM Role for Nodes Launched by Karpenter

EKS Fargate Profile for Karpenter and IAM Role for Nodes launched by Karpenter are provisioned by the eks/cluster component:

components:
  terraform:
    eks/cluster-blue:
      metadata:
        component: eks/cluster
        inherits:
          - eks/cluster
      vars:
        attributes:
          - blue
        eks_component_name: eks/cluster-blue
        node_groups:
          main:
            instance_types:
              - t3.medium
            max_group_size: 3
            min_group_size: 1
        fargate_profiles:
          karpenter:
            kubernetes_namespace: karpenter
            kubernetes_labels: null
        karpenter_iam_role_enabled: true

Notes:

Fargate Profile role ARNs need to be added to the aws-auth ConfigMap to allow the Fargate Profile nodes to join the EKS cluster (this is done by EKS)
Karpenter IAM role ARN needs to be added to the aws-auth ConfigMap to allow the nodes launched by Karpenter to join the EKS cluster (this is done by the eks/cluster component)

We use EKS Fargate Profile for Karpenter because It is recommended to run Karpenter on an EKS Fargate Profile.

Karpenter is installed using a Helm chart. The Helm chart installs the Karpenter controller and
a webhook pod as a Deployment that needs to run before the controller can be used for scaling your cluster.
We recommend a minimum of one small node group with at least one worker node.

As an alternative, you can run these pods on EKS Fargate by creating a Fargate profile for the
karpenter namespace. Doing so will cause all pods deployed into this namespace to run on EKS Fargate.
Do not run Karpenter on a node that is managed by Karpenter.

See Run Karpenter Controller on EKS Fargate for more details.

We provision IAM Role for Nodes launched by Karpenter because they must run with an Instance Profile that grants permissions necessary to run containers and configure networking.

We define the IAM role for the Instance Profile in components/terraform/eks/cluster/karpenter.tf.

Note that we provision the EC2 Instance Profile for the Karpenter IAM role in the components/terraform/eks/karpenter component (see the next step).

Run the following commands to provision the EKS Fargate Profile for Karpenter and the IAM role for instances launched by Karpenter on the blue EKS cluster and add the role ARNs to the aws-auth ConfigMap:

atmos terraform plan eks/cluster-blue -s plat-ue2-dev
atmos terraform apply eks/cluster-blue -s plat-ue2-dev

For more details, refer to:

2. Provision `karpenter` component

In this step, we provision the components/terraform/eks/karpenter component, which deploys the following resources:

EC2 Instance Profile for the nodes launched by Karpenter (note that the IAM role for the Instance Profile is provisioned in the previous step in the eks/cluster component)
Karpenter Kubernetes controller using the Karpenter Helm Chart and the helm_release Terraform resource
EKS IAM role for Kubernetes Service Account for the Karpenter controller (with all the required permissions)

Run the following commands to provision the Karpenter component on the blue EKS cluster:

atmos terraform plan eks/karpenter-blue -s plat-ue2-dev
atmos terraform apply eks/karpenter-blue -s plat-ue2-dev

Note that the stack config for the blue Karpenter component is defined in stacks/catalog/eks/clusters/blue.yaml.

    eks/karpenter-blue:
      metadata:
        component: eks/karpenter
        inherits:
          - eks/karpenter
      vars:
        eks_component_name: eks/cluster-blue

3. Provision `karpenter-provisioner` component

In this step, we provision the components/terraform/eks/karpenter-provisioner component, which deploys Karpenter Provisioners using the kubernetes_manifest resource.

NOTE: We deploy the provisioners in a separate step as a separate component since it uses kind: Provisioner CRD which itself is created by the karpenter component in the previous step.

Run the following commands to deploy the Karpenter provisioners on the blue EKS cluster:

atmos terraform plan eks/karpenter-provisioner-blue -s plat-ue2-dev
atmos terraform apply eks/karpenter-provisioner-blue -s plat-ue2-dev

Note that the stack config for the blue Karpenter provisioner component is defined in stacks/catalog/eks/clusters/blue.yaml.

    eks/karpenter-provisioner-blue:
      metadata:
        component: eks/karpenter-provisioner
        inherits:
          - eks/karpenter-provisioner
      vars:
        attributes:
          - blue
        eks_component_name: eks/cluster-blue

You can override the default values from the eks/karpenter-provisioner base component.

For your cluster, you will need to review the following configurations for the Karpenter provisioners and update it according to your requirements:

requirements:

    requirements:
      - key: "karpenter.sh/capacity-type"
        operator: "In"
        values:
          - "on-demand"
          - "spot"
      - key: "node.kubernetes.io/instance-type"
        operator: "In"
        values:
          - "m5.xlarge"
          - "m5.large"
          - "m5.medium"
          - "c5.xlarge"
          - "c5.large"
          - "c5.medium"
      - key: "kubernetes.io/arch"
        operator: "In"
        values:
          - "amd64"

taints, startup_taints, ami_family

Resource limits/requests for the Karpenter controller itself:

    resources:
      limits:
        cpu: "300m"
        memory: "1Gi"
      requests:
        cpu: "100m"
        memory: "512Mi"

Total CPU and memory limits for all pods running on the EC2 instances launched by Karpenter:
```
  total_cpu_limit: "1k"
  total_memory_limit: "1000Gi"
```
Config to terminate empty nodes after the specified number of seconds. This behavior can be disabled by setting the value to null (never scales down if not set):
```
  ttl_seconds_after_empty: 30
```
Config to terminate nodes when a maximum age is reached. This behavior can be disabled by setting the value to null (never expires if not set):
```
  ttl_seconds_until_expired: 2592000
```

Troubleshooting

For Karpenter issues, checkout the Karpenter Troubleshooting Guide

References

For more details, refer to:

Requirements

Name	Version
terraform	>= 1.0.0
aws	>= 4.9.0
helm	>= 2.0
kubernetes	>= 2.7.1, != 2.21.0

Providers

Name	Version
aws	>= 4.9.0

Modules

Name	Source	Version
eks	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
iam_roles	../../account-map/modules/iam-roles	n/a
karpenter	cloudposse/helm-release/aws	0.10.0
this	cloudposse/label/null	0.25.0

Resources

Name	Type
aws_cloudwatch_event_rule.interruption_handler	resource
aws_cloudwatch_event_target.interruption_handler	resource
aws_iam_instance_profile.default	resource
aws_sqs_queue.interruption_handler	resource
aws_sqs_queue_policy.interruption_handler	resource
aws_eks_cluster_auth.eks	data source
aws_iam_policy_document.interruption_handler	data source
aws_partition.current	data source

Inputs

Name	Description	Type	Default	Required
additional_tag_map	Additional key-value pairs to add to each map in `tags_as_list_of_maps`. Not added to `tags` or `id`. This is for some rare cases where resources want additional configuration of tags and therefore take a list of maps with tag key, value, and additional configuration.	`map(string)`	`{}`	no
atomic	If set, installation process purges chart on fail. The wait flag will be set automatically if atomic is used	`bool`	`true`	no
attributes	ID element. Additional attributes (e.g. `workers` or `cluster`) to add to `id`, in the order they appear in the list. New attributes are appended to the end of the list. The elements of the list are joined by the `delimiter` and treated as a single ID element.	`list(string)`	`[]`	no
chart	Chart name to be installed. The chart name can be local path, a URL to a chart, or the name of the chart if `repository` is specified. It is also possible to use the `<repository>/<chart>` format here if you are running Terraform on a system that the repository has been added to with `helm repo add` but this is not recommended	`string`	n/a	yes
chart_description	Set release description attribute (visible in the history)	`string`	`null`	no
chart_repository	Repository URL where to locate the requested chart	`string`	n/a	yes
chart_values	Additional values to yamlencode as `helm_release` values	`any`	`{}`	no
chart_version	Specify the exact chart version to install. If this is not specified, the latest version is installed	`string`	`null`	no
cleanup_on_fail	Allow deletion of new resources created in this upgrade when upgrade fails	`bool`	`true`	no
context	Single object for setting entire context at once. See description of individual variables for details. Leave string and numeric variables as `null` to use default value. Individual variable settings (non-null) override settings in context object, except for attributes, tags, and additional_tag_map, which are merged.	`any`	`{ "additional_tag_map": {}, "attributes": [], "delimiter": null, "descriptor_formats": {}, "enabled": true, "environment": null, "id_length_limit": null, "label_key_case": null, "label_order": [], "label_value_case": null, "labels_as_tags": [ "unset" ], "name": null, "namespace": null, "regex_replace_chars": null, "stage": null, "tags": {}, "tenant": null }`	no
create_namespace	Create the namespace if it does not yet exist. Defaults to `false`	`bool`	`null`	no
delimiter	Delimiter to be used between ID elements. Defaults to `-` (hyphen). Set to `""` to use no delimiter at all.	`string`	`null`	no
descriptor_formats	Describe additional descriptors to be output in the `descriptors` output map. Map of maps. Keys are names of descriptors. Values are maps of the form `{<br/> format = string<br/> labels = list(string)<br/>}` (Type is `any` so the map values can later be enhanced to provide additional options.) `format` is a Terraform format string to be passed to the `format()` function. `labels` is a list of labels, in order, to pass to `format()` function. Label values will be normalized before being passed to `format()` so they will be identical to how they appear in `id`. Default is `{}` (`descriptors` output will be empty).	`any`	`{}`	no
eks_component_name	The name of the eks component	`string`	`"eks/cluster"`	no
enabled	Set to false to prevent the module from creating any resources	`bool`	`null`	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	`string`	`null`	no
helm_manifest_experiment_enabled	Enable storing of the rendered manifest for helm_release so the full diff of what is changing can been seen in the plan	`bool`	`false`	no
id_length_limit	Limit `id` to this many characters (minimum 6). Set to `0` for unlimited length. Set to `null` for keep the existing setting, which defaults to `0`. Does not affect `id_full`.	`number`	`null`	no
interruption_handler_enabled	If `true`, deploy a SQS queue and Event Bridge rules to enable interruption handling by Karpenter. https://karpenter.sh/v0.27.5/concepts/deprovisioning/#interruption	`bool`	`false`	no
interruption_queue_message_retention	The message retention in seconds for the interruption handler SQS queue.	`number`	`300`	no
kube_data_auth_enabled	If `true`, use an `aws_eks_cluster_auth` data source to authenticate to the EKS cluster. Disabled by `kubeconfig_file_enabled` or `kube_exec_auth_enabled`.	`bool`	`false`	no
kube_exec_auth_aws_profile	The AWS config profile for `aws eks get-token` to use	`string`	`""`	no
kube_exec_auth_aws_profile_enabled	If `true`, pass `kube_exec_auth_aws_profile` as the `profile` to `aws eks get-token`	`bool`	`false`	no
kube_exec_auth_enabled	If `true`, use the Kubernetes provider `exec` feature to execute `aws eks get-token` to authenticate to the EKS cluster. Disabled by `kubeconfig_file_enabled`, overrides `kube_data_auth_enabled`.	`bool`	`true`	no
kube_exec_auth_role_arn	The role ARN for `aws eks get-token` to use	`string`	`""`	no
kube_exec_auth_role_arn_enabled	If `true`, pass `kube_exec_auth_role_arn` as the role ARN to `aws eks get-token`	`bool`	`true`	no
kubeconfig_context	Context to choose from the Kubernetes kube config file	`string`	`""`	no
kubeconfig_exec_auth_api_version	The Kubernetes API version of the credentials returned by the `exec` auth plugin	`string`	`"client.authentication.k8s.io/v1beta1"`	no
kubeconfig_file	The Kubernetes provider `config_path` setting to use when `kubeconfig_file_enabled` is `true`	`string`	`""`	no
kubeconfig_file_enabled	If `true`, configure the Kubernetes provider with `kubeconfig_file` and use that kubeconfig file for authenticating to the EKS cluster	`bool`	`false`	no
kubernetes_namespace	The namespace to install the release into	`string`	n/a	yes
label_key_case	Controls the letter case of the `tags` keys (label names) for tags generated by this module. Does not affect keys of tags passed in via the `tags` input. Possible values: `lower`, `title`, `upper`. Default value: `title`.	`string`	`null`	no
label_order	The order in which the labels (ID elements) appear in the `id`. Defaults to ["namespace", "environment", "stage", "name", "attributes"]. You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.	`list(string)`	`null`	no
label_value_case	Controls the letter case of ID elements (labels) as included in `id`, set as tag values, and output by this module individually. Does not affect values of tags passed in via the `tags` input. Possible values: `lower`, `title`, `upper` and `none` (no transformation). Set this to `title` and set `delimiter` to `""` to yield Pascal Case IDs. Default value: `lower`.	`string`	`null`	no
labels_as_tags	Set of labels (ID elements) to include as tags in the `tags` output. Default is to include all labels. Tags with empty values will not be included in the `tags` output. Set to `[]` to suppress all generated tags. Notes: The value of the `name` tag, if included, will be the `id`, not the `name`. Unlike other `null-label` inputs, the initial setting of `labels_as_tags` cannot be changed in later chained modules. Attempts to change it will be silently ignored.	`set(string)`	`[ "default" ]`	no
legacy_create_karpenter_instance_profile	When `true` (the default), this component creates an IAM Instance Profile for nodes launched by Karpenter, to preserve the legacy behavior. Set to `false` to disable creation of the IAM Instance Profile, which avoids conflict with having `eks/cluster` create it. Use in conjunction with `eks/cluster` component `legacy_do_not_create_karpenter_instance_profile`, which see for further details.	`bool`	`true`	no
name	ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'. This is the only ID element not also included as a `tag`. The "name" tag is set to the full `id` string. There is no tag with the value of the `name` input.	`string`	`null`	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	`string`	`null`	no
rbac_enabled	Enable/disable RBAC	`bool`	`true`	no
regex_replace_chars	Terraform regular expression (regex) string. Characters matching the regex will be removed from the ID elements. If not set, `"/[^a-zA-Z0-9-]/"` is used to remove all characters other than hyphens, letters and digits.	`string`	`null`	no
region	AWS Region	`string`	n/a	yes
resources	The CPU and memory of the deployment's limits and requests	`object({ limits = object({ cpu = string memory = string }) requests = object({ cpu = string memory = string }) })`	n/a	yes
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	`string`	`null`	no
tags	Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`). Neither the tag keys nor the tag values will be modified by this module.	`map(string)`	`{}`	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	`string`	`null`	no
timeout	Time in seconds to wait for any individual kubernetes operation (like Jobs for hooks). Defaults to `300` seconds	`number`	`null`	no
wait	Will wait until all resources are in a ready state before marking the release as successful. It will wait for as long as `timeout`. Defaults to `true`	`bool`	`null`	no

Outputs

Name	Description
instance_profile	Provisioned EC2 Instance Profile for nodes launched by Karpenter
metadata	Block status of the deployed release

Component: eks/karpenter

Usage​

Provision Karpenter on EKS cluster​

Provision Service-Linked Roles for EC2 Spot and EC2 Spot Fleet​

1. Provision EKS Fargate Profile for Karpenter and IAM Role for Nodes Launched by Karpenter​

2. Provision karpenter component​

3. Provision karpenter-provisioner component​

Troubleshooting​

References​

Requirements​

Providers​

Modules​

Resources​

Inputs​

Outputs​

References​

Component: `eks/karpenter`

Usage

Provision Karpenter on EKS cluster

Provision Service-Linked Roles for EC2 Spot and EC2 Spot Fleet

1. Provision EKS Fargate Profile for Karpenter and IAM Role for Nodes Launched by Karpenter

2. Provision `karpenter` component

3. Provision `karpenter-provisioner` component

Troubleshooting

References

Requirements

Providers

Modules

Resources

Inputs

Outputs

References