test-mcp-glama

--- title: "NodeClasses" linkTitle: "NodeClasses" weight: 2 description: > Configure AWS-specific settings with EC2NodeClasses --- Node Classes enable configuration of AWS specific settings. Each NodePool must reference an EC2NodeClass using `spec.template.spec.nodeClassRef`. Multiple NodePools may point to the same EC2NodeClass. ```yaml apiVersion: karpenter.sh/v1 kind: NodePool metadata: name: default spec: template: spec: nodeClassRef: group: karpenter.k8s.aws kind: EC2NodeClass name: default --- apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass metadata: name: default spec: kubelet: podsPerCore: 2 maxPods: 20 systemReserved: cpu: 100m memory: 100Mi ephemeral-storage: 1Gi kubeReserved: cpu: 200m memory: 100Mi ephemeral-storage: 3Gi evictionHard: memory.available: 5% nodefs.available: 10% nodefs.inodesFree: 10% evictionSoft: memory.available: 500Mi nodefs.available: 15% nodefs.inodesFree: 15% evictionSoftGracePeriod: memory.available: 1m nodefs.available: 1m30s nodefs.inodesFree: 2m evictionMaxPodGracePeriod: 60 imageGCHighThresholdPercent: 85 imageGCLowThresholdPercent: 80 cpuCFSQuota: true clusterDNS: ["10.0.1.100"] # Optional, dictates UserData generation and default block device mappings. # May be ommited when using an `alias` amiSelectorTerm, otherwise required. amiFamily: AL2 # Required, discovers subnets to attach to instances # Each term in the array of subnetSelectorTerms is ORed together # Within a single term, all conditions are ANDed subnetSelectorTerms: # Select on any subnet that has the "karpenter.sh/discovery: ${CLUSTER_NAME}" # AND the "environment: test" tag OR any subnet with ID "subnet-09fa4a0a8f233a921" - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - id: subnet-09fa4a0a8f233a921 # Required, discovers security groups to attach to instances # Each term in the array of securityGroupSelectorTerms is ORed together # Within a single term, all conditions are ANDed securityGroupSelectorTerms: # Select on any security group that has both the "karpenter.sh/discovery: ${CLUSTER_NAME}" tag # AND the "environment: test" tag OR any security group with the "my-security-group" name # OR any security group with ID "sg-063d7acfb4b06c82c" - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - name: my-security-group - id: sg-063d7acfb4b06c82c # Optional, IAM role to use for the node identity. # Must specify one of "role" or "instanceProfile" for Karpenter to launch nodes role: "KarpenterNodeRole-${CLUSTER_NAME}" # Optional, IAM instance profile to use for the node identity. # Must specify one of "role" or "instanceProfile" for Karpenter to launch nodes instanceProfile: "KarpenterNodeInstanceProfile-${CLUSTER_NAME}" # Each term in the array of amiSelectorTerms is ORed together # Within a single term, all conditions are ANDed amiSelectorTerms: # Select on any AMI that has both the `karpenter.sh/discovery: ${CLUSTER_NAME}` # AND `environment: test` tags OR any AMI with the name `my-ami` OR an AMI with # ID `ami-123` OR an AMI with ID matching the value of my-custom-parameter - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - name: my-ami - id: ami-123 - ssmParameter: my-custom-parameter # ssm parameter name or ARN # Select EKS optimized AL2023 AMIs with version `v20240703`. This term is mutually # exclusive and can't be specified with other terms. # - alias: al2023@v20240703 # Optional, each term in the array of capacityReservationSelectorTerms is ORed together. capacityReservationSelectorTerms: - tags: karpenter.sh/discovery: ${CLUSTER_NAME} - id: cr-123 - instanceMatchCriteria: open # Optional, propagates tags to underlying EC2 resources tags: team: team-a app: team-a-app # Optional, configures IMDS for the instance metadataOptions: httpEndpoint: enabled httpProtocolIPv6: disabled httpPutResponseHopLimit: 1 # This is changed to disable IMDS access from containers not on the host network httpTokens: required # Optional, configures storage devices for the instance blockDeviceMappings: - deviceName: /dev/xvda ebs: volumeSize: 100Gi volumeType: gp3 iops: 10000 encrypted: true kmsKeyID: "1234abcd-12ab-34cd-56ef-1234567890ab" deleteOnTermination: true throughput: 125 snapshotID: snap-0123456789 volumeInitializationRate: 100 # Optional, use instance-store volumes for node ephemeral-storage instanceStorePolicy: RAID0 # Optional, overrides autogenerated userdata with a merge semantic userData: | echo "Hello world" # Optional, configures detailed monitoring for the instance detailedMonitoring: true # Optional, configures if the instance should be launched with an associated public IP address. # If not specified, the default value depends on the subnet's public IP auto-assign setting. associatePublicIPAddress: true status: # Resolved subnets subnets: - id: subnet-0a462d98193ff9fac zone: us-east-2b - id: subnet-0322dfafd76a609b6 zone: us-east-2c - id: subnet-0727ef01daf4ac9fe zone: us-east-2b - id: subnet-00c99aeafe2a70304 zone: us-east-2a - id: subnet-023b232fd5eb0028e zone: us-east-2c - id: subnet-03941e7ad6afeaa72 zone: us-east-2a # Resolved security groups securityGroups: - id: sg-041513b454818610b name: ClusterSharedNodeSecurityGroup - id: sg-0286715698b894bca name: ControlPlaneSecurityGroup-1AQ073TSAAPW # Resolved AMIs amis: - id: ami-01234567890123456 name: custom-ami-amd64 requirements: - key: kubernetes.io/arch operator: In values: - amd64 - id: ami-01234567890123456 name: custom-ami-arm64 requirements: - key: kubernetes.io/arch operator: In values: - arm64 # Capacity Reservations capacityReservations: - availabilityZone: us-west-2a id: cr-01234567890123456 instanceMatchCriteria: targeted instanceType: g6.48xlarge ownerID: "012345678901" reservationType: capacity-block state: expiring - availabilityZone: us-west-2c id: cr-12345678901234567 instanceMatchCriteria: open instanceType: g6.48xlarge ownerID: "98765432109" reservationType: default state: active # Generated instance profile name from "role" instanceProfile: "${CLUSTER_NAME}-0123456778901234567789" conditions: - lastTransitionTime: "2024-02-02T19:54:34Z" status: "True" type: InstanceProfileReady - lastTransitionTime: "2024-02-02T19:54:34Z" status: "True" type: SubnetsReady - lastTransitionTime: "2024-02-02T19:54:34Z" status: "True" type: SecurityGroupsReady - lastTransitionTime: "2024-02-02T19:54:34Z" status: "True" type: AMIsReady - lastTransitionTime: "2024-02-02T19:54:34Z" status: "True" type: Ready ``` Refer to the [NodePool docs]({{<ref "./nodepools" >}}) for settings applicable to all providers. To explore various `EC2NodeClass` configurations, refer to the examples provided [in the Karpenter Github repository](https://github.com/aws/karpenter/blob/main/examples/v1/). ## spec.kubelet Karpenter provides the ability to specify a few additional Kubelet arguments. These are all optional and provide support for additional customization and use cases. Adjust these only if you know you need to do so. For more details on kubelet settings, see the [KubeletConfiguration reference](https://kubernetes.io/docs/reference/config-api/kubelet-config.v1/). The implemented fields are a subset of the full list of upstream kubelet configuration arguments. ```yaml kubelet: podsPerCore: 2 maxPods: 20 systemReserved: cpu: 100m memory: 100Mi ephemeral-storage: 1Gi kubeReserved: cpu: 200m memory: 100Mi ephemeral-storage: 3Gi evictionHard: memory.available: 5% nodefs.available: 10% nodefs.inodesFree: 10% evictionSoft: memory.available: 500Mi nodefs.available: 15% nodefs.inodesFree: 15% evictionSoftGracePeriod: memory.available: 1m nodefs.available: 1m30s nodefs.inodesFree: 2m evictionMaxPodGracePeriod: 60 imageGCHighThresholdPercent: 85 imageGCLowThresholdPercent: 80 cpuCFSQuota: true clusterDNS: ["10.0.1.100"] ``` {{% alert title="Note" color="primary" %}} If you need to specify a field that isn't present in `spec.kubelet`, you can set it via custom [UserData]({{< ref "#specuserdata" >}}). For example, if you wanted to configure `maxPods` and `registryPullQPS` you would set the former through `spec.kubelet` and the latter through UserData. The following example achieves this with AL2023: ```yaml apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass spec: amiSelectorTerms: - alias: al2023@v20240807 kubelet: maxPods: 42 userData: | apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: kubelet: config: # Configured through UserData since unavailable in `spec.kubelet` registryPullQPS: 10 ``` Note that when using the `Custom` AMIFamily you will need to specify fields **both** in `spec.kubelet` and `spec.userData`. {{% /alert %}} #### Pods Per Core An alternative way to dynamically set the maximum density of pods on a node is to use the `.spec.kubelet.podsPerCore` value. Karpenter will calculate the pod density during scheduling by multiplying this value by the number of logical cores (vCPUs) on an instance type. This value will also be passed through to the `--pods-per-core` value on kubelet startup to configure the number of allocatable pods the kubelet can assign to the node instance. The value generated from `podsPerCore` cannot exceed `maxPods`, meaning, if both are set, the minimum of the `podsPerCore` dynamic pod density and the static `maxPods` value will be used for scheduling. {{% alert title="Note" color="primary" %}} `maxPods` may not be set in the `kubelet` of an EC2NodeClass, but may still be restricted by the `ENI_LIMITED_POD_DENSITY` value. You may want to ensure that the `podsPerCore` value that will be used for instance families associated with the EC2NodeClass will not cause unexpected behavior by exceeding the `maxPods` value. {{% /alert %}} #### Max Pods For small instances that require an increased pod density or large instances that require a reduced pod density, you can override this default value with `.spec.kubelet.maxPods`. This value will be used during Karpenter pod scheduling and passed through to `--max-pods` on kubelet startup. {{% alert title="Note" color="primary" %}} When using small instance types, it may be necessary to enable [prefix assignment mode](https://aws.amazon.com/blogs/containers/amazon-vpc-cni-increases-pods-per-node-limits/) in the AWS VPC CNI plugin to support a higher pod density per node. Prefix assignment mode was introduced in AWS VPC CNI v1.9 and allows ENIs to manage a broader set of IP addresses. Much higher pod densities are supported as a result. {{% /alert %}} {{% alert title="Windows Support Notice" color="warning" %}} Presently, Windows worker nodes do not support using more than one ENI. As a consequence, the number of IP addresses, and subsequently, the number of pods that a Windows worker node can support is limited by the number of IPv4 addresses available on the primary ENI. Currently, Karpenter will only consider individual secondary IP addresses when calculating the pod density limit. {{% /alert %}} ### Reserved Resources Karpenter will automatically configure the system and kube reserved resource requests on the fly on your behalf. These requests are used to configure your node and to make scheduling decisions for your pods. If you have specific requirements or know that you will have additional capacity requirements, you can optionally override the `--system-reserved` configuration defaults with the `.spec.kubelet.systemReserved` values and the `--kube-reserved` configuration defaults with the `.spec.kubelet.kubeReserved` values. {{% alert title="Note" color="primary" %}} Karpenter considers these reserved resources when computing the allocatable ephemeral storage on a given instance type. If `kubeReserved` is not specified, Karpenter will compute the default reserved [CPU](https://github.com/awslabs/amazon-eks-ami/blob/db28da15d2b696bc08ac3aacc9675694f4a69933/files/bootstrap.sh#L251) and [memory](https://github.com/awslabs/amazon-eks-ami/blob/db28da15d2b696bc08ac3aacc9675694f4a69933/files/bootstrap.sh#L235) resources for the purpose of ephemeral storage computation. These defaults are based on the defaults on Karpenter's supported AMI families, which are not the same as the kubelet defaults. You should be aware of the CPU and memory default calculation when using Custom AMI Families. If they don't align, there may be a difference in Karpenter's computed allocatable ephemeral storage and the actually ephemeral storage available on the node. {{% /alert %}} ### Eviction Thresholds The kubelet supports eviction thresholds by default. When enough memory or file system pressure is exerted on the node, the kubelet will begin to evict pods to ensure that system daemons and other system processes can continue to run in a healthy manner. Kubelet has the notion of [hard evictions](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#hard-eviction-thresholds) and [soft evictions](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#soft-eviction-thresholds). In hard evictions, pods are evicted as soon as a threshold is met, with no grace period to terminate. Soft evictions, on the other hand, provide an opportunity for pods to be terminated gracefully. They do so by sending a termination signal to pods that are planning to be evicted and allowing those pods to terminate up to their grace period. Karpenter supports [hard evictions](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#hard-eviction-thresholds) through the `.spec.kubelet.evictionHard` field and [soft evictions](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#soft-eviction-thresholds) through the `.spec.kubelet.evictionSoft` field. `evictionHard` and `evictionSoft` are configured by listing [signal names](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/#eviction-signals) with either percentage values or resource values. ```yaml kubelet: evictionHard: memory.available: 500Mi nodefs.available: 10% nodefs.inodesFree: 10% imagefs.available: 5% imagefs.inodesFree: 5% pid.available: 7% evictionSoft: memory.available: 1Gi nodefs.available: 15% nodefs.inodesFree: 15% imagefs.available: 10% imagefs.inodesFree: 10% pid.available: 10% ``` #### Supported Eviction Signals | Eviction Signal | Description | |--------------------|---------------------------------------------------------------------------------| | memory.available | memory.available := node.status.capacity[memory] - node.stats.memory.workingSet | | nodefs.available | nodefs.available := node.stats.fs.available | | nodefs.inodesFree | nodefs.inodesFree := node.stats.fs.inodesFree | | imagefs.available | imagefs.available := node.stats.runtime.imagefs.available | | imagefs.inodesFree | imagefs.inodesFree := node.stats.runtime.imagefs.inodesFree | | pid.available | pid.available := node.stats.rlimit.maxpid - node.stats.rlimit.curproc | For more information on eviction thresholds, view the [Node-pressure Eviction](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction) section of the official Kubernetes docs. #### Soft Eviction Grace Periods Soft eviction pairs an eviction threshold with a specified grace period. With soft eviction thresholds, the kubelet will only begin evicting pods when the node exceeds its soft eviction threshold over the entire duration of its grace period. For example, if you specify `evictionSoft[memory.available]` of `500Mi` and a `evictionSoftGracePeriod[memory.available]` of `1m30`, the node must have less than `500Mi` of available memory over a minute and a half in order for the kubelet to begin evicting pods. Optionally, you can specify an `evictionMaxPodGracePeriod` which defines the administrator-specified maximum pod termination grace period to use during soft eviction. If a namespace-owner had specified a pod `terminationGracePeriodInSeconds` on pods in their namespace, the minimum of `evictionPodGracePeriod` and `terminationGracePeriodInSeconds` would be used. ```yaml kubelet: evictionSoftGracePeriod: memory.available: 1m nodefs.available: 1m30s nodefs.inodesFree: 2m imagefs.available: 1m30s imagefs.inodesFree: 2m pid.available: 2m evictionMaxPodGracePeriod: 60 ``` ### Pod Density By default, the number of pods on a node is limited by both the number of networking interfaces (ENIs) that may be attached to an instance type and the number of IP addresses that can be assigned to each ENI. See [IP addresses per network interface per instance type](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html#AvailableIpPerENI) for a more detailed information on these instance types' limits. {{% alert title="Note" color="primary" %}} By default, the VPC CNI allocates IPs for a node and pods from the same subnet. With [VPC CNI Custom Networking](https://aws.github.io/aws-eks-best-practices/networking/custom-networking), the pods will receive IP addresses from another subnet dedicated to pod IPs. This approach makes it easier to manage IP addresses and allows for separate Network Access Control Lists (NACLs) applied to your pods. VPC CNI Custom Networking reduces the pod density of a node since one of the ENI attachments will be used for the node and cannot share the allocated IPs on the interface to pods. Karpenter supports VPC CNI Custom Networking and similar CNI setups where the primary node interface is separated from the pods interfaces through a global environment variable RESERVED_ENIS, see [Settings]({{<ref "../reference/settings" >}}). In the common case, RESERVED_ENIS should be set to "1" if using Custom Networking. {{% /alert %}} {{% alert title="Windows Support Notice" color="warning" %}} It's currently not possible to specify custom networking with Windows nodes. {{% /alert %}} ## spec.amiFamily AMIFamily dictates the default bootstrapping logic for nodes provisioned through this `EC2NodeClass`. An `amiFamily` is only required if you don't specify a `spec.amiSelectorTerms.alias` object. For example, if you specify `alias: al2023@v20240807`, the `amiFamily` is implicitly `AL2023`. AMIFamily does not impact which AMI is discovered, only the UserData generation and default BlockDeviceMappings. To automatically discover EKS optimized AMIs, use the new [`alias` field in amiSelectorTerms]({{< ref "#specamiselectorterms" >}}). {{% alert title="Ubuntu Support Dropped at v1" color="warning" %}} Support for the Ubuntu AMIFamily has been dropped at Karpenter `v1.0.0`. This means Karpenter no longer supports automatic AMI discovery and UserData generation for Ubuntu. To continue using Ubuntu AMIs, you will need to select Ubuntu AMIs using `amiSelectorTerms`. Additionally, you will need to either maintain UserData yourself using the `Custom` AMIFamily, or you can use the `AL2` AMIFamily and custom `blockDeviceMappings` (as shown below). The `AL2` family has an identical UserData format, but this compatibility isn't guaranteed long term. Changes to AL2's or Ubuntu's UserData format could result in incompatibility, at which point the `Custom` AMIFamily must be used. **Ubuntu NodeClass Example:** ```yaml apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass spec: amiFamily: AL2 amiSelectorTerms: - id: ami-placeholder blockDeviceMappings: - deviceName: '/dev/sda1' rootVolume: true ebs: encrypted: true volumeType: gp3 volumeSize: 20Gi ``` {{% /alert %}} ### AL2 {{% alert title="AL2 support dropped at Kubernetes 1.33" color="warning" %}} Kubernetes version 1.32 is the last version for which Amazon EKS will release Amazon Linux 2 (AL2) AMIs. {{% /alert %}} {{% alert title="Note" color="primary" %}} Note that Karpenter will automatically generate a call to the `/etc/eks/bootstrap.sh` script as part of its generated UserData. When using `amiFamily: AL2` you should not call this script yourself in `.spec.userData`. If you need to, use the [Custom AMI family]({{< ref "./nodeclasses/#custom" >}}) instead. {{% /alert %}} ```bash MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash -xe exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1 /etc/eks/bootstrap.sh 'test-cluster' --apiserver-endpoint 'https://test-cluster' --b64-cluster-ca 'ca-bundle' \ --dns-cluster-ip '10.100.0.10' \ --use-max-pods false \ --kubelet-extra-args '--node-labels=karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test --max-pods=110' --//-- ``` ### AL2023 ```text MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: application/node.eks.aws # Karpenter Generated NodeConfig apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: cluster: name: test-cluster apiServerEndpoint: https://example.com certificateAuthority: ca-bundle cidr: 10.100.0.0/16 kubelet: config: maxPods: 110 flags: - --node-labels=karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test --//-- ``` ### Bottlerocket ```toml [settings] [settings.kubernetes] api-server = 'https://test-cluster' cluster-certificate = 'ca-bundle' cluster-name = 'test-cluster' cluster-dns-ip = '10.100.0.10' max-pods = 110 [settings.kubernetes.node-labels] 'karpenter.sh/capacity-type' = 'on-demand' 'karpenter.sh/nodepool' = 'test' ``` ### Windows2019 ```powershell <powershell> [string]$EKSBootstrapScriptFile = "$env:ProgramFiles\Amazon\EKS\Start-EKSBootstrap.ps1" & $EKSBootstrapScriptFile -EKSClusterName 'test-cluster' -APIServerEndpoint 'https://test-cluster' -Base64ClusterCA 'ca-bundle' -KubeletExtraArgs '--node-labels="karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test" --max-pods=110' -DNSClusterIP '10.100.0.10' </powershell> ``` ### Windows2022 ```powershell <powershell> [string]$EKSBootstrapScriptFile = "$env:ProgramFiles\Amazon\EKS\Start-EKSBootstrap.ps1" & $EKSBootstrapScriptFile -EKSClusterName 'test-cluster' -APIServerEndpoint 'https://test-cluster' -Base64ClusterCA 'ca-bundle' -KubeletExtraArgs '--node-labels="karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test" --max-pods=110' -DNSClusterIP '10.100.0.10' </powershell> ``` ### Custom The `Custom` AMIFamily ships without any default userData to allow you to configure custom bootstrapping for control planes or images that don't support the default methods from the other families. For this AMIFamily, kubelet must add the taint `karpenter.sh/unregistered:NoExecute` via the `--register-with-taints` flag ([flags](https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/#options)) or the KubeletConfiguration spec ([options](https://kubernetes.io/docs/reference/config-api/kubelet-config.v1/#kubelet-config-k8s-io-v1-CredentialProviderConfig) and [docs](https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/)). Karpenter will fail to register nodes that do not have this taint. ## spec.subnetSelectorTerms Subnet Selector Terms allow you to specify selection logic for a set of subnet options that Karpenter can choose from when launching an instance from the `EC2NodeClass`. Karpenter discovers subnets through the `EC2NodeClass` using ids or [tags](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html). When launching nodes, a subnet is automatically chosen that matches the desired zone. If multiple subnets exist for a zone, the one with the most available IP addresses will be used. This selection logic is modeled as terms, where each term contains multiple conditions that must all be satisfied for the selector to match. Effectively, all requirements within a single term are ANDed together. It's possible that you may want to select on two different subnets that have unrelated requirements. In this case, you can specify multiple terms which will be ORed together to form your selection logic. The example below shows how this selection logic is fulfilled. ```yaml subnetSelectorTerms: # Select on any subnet that has the "karpenter.sh/discovery: ${CLUSTER_NAME}" # AND the "environment: test" tag OR any subnet with ID "subnet-09fa4a0a8f233a921" - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - id: subnet-09fa4a0a8f233a921 ``` {{% alert title="Tip" color="secondary" %}} Subnets may be specified by any tag, including `Name`. Selecting tag values using wildcards (`*`) is supported. {{% /alert %}} #### Examples Select all with a specified tag key: ```yaml spec: subnetSelectorTerms: - tags: karpenter.sh/discovery/MyClusterName: '*' ``` Select by name and tag (all criteria must match): ```yaml spec: subnetSelectorTerms: - tags: Name: my-subnet MyTag: '' # matches all resources with the tag ``` Select using multiple tag terms: ```yaml spec: subnetSelectorTerms: - tags: Name: "my-subnet-1" - tags: Name: "my-subnet-2" ``` Select using wildcards: ```yaml spec: subnetSelectorTerms: - tags: Name: "*Public*" ``` Select using ids: ```yaml spec: subnetSelectorTerms: - id: "subnet-09fa4a0a8f233a921" - id: "subnet-0471ca205b8a129ae" ``` ## spec.securityGroupSelectorTerms Security Group Selector Terms allow you to specify selection logic for all security groups that will be attached to an instance launched from the `EC2NodeClass`. The security group of an instance is comparable to a set of firewall rules. [EKS creates at least two security groups by default](https://docs.aws.amazon.com/eks/latest/userguide/sec-group-reqs.html). This selection logic is modeled as terms, where each term contains multiple conditions that must all be satisfied for the selector to match. Effectively, all requirements within a single term are ANDed together. It's possible that you may want to select on two different security groups that have unrelated requirements. In this case, you can specify multiple terms which will be ORed together to form your selection logic. The example below shows how this selection logic is fulfilled. ```yaml securityGroupSelectorTerms: # Select on any security group that has both the "karpenter.sh/discovery: ${CLUSTER_NAME}" tag # AND the "environment: test" tag OR any security group with the "my-security-group" name # OR any security group with ID "sg-063d7acfb4b06c82c" - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - name: my-security-group - id: sg-063d7acfb4b06c82c ``` {{% alert title="Tip" color="secondary" %}} Security groups may be specified by any tag, including "Name". Selecting tags using wildcards (`*`) is supported. {{% /alert %}} {{% alert title="Note" color="primary" %}} When launching nodes, Karpenter uses all the security groups that match the selector. If you choose to use the `kubernetes.io/cluster/$CLUSTER_NAME` tag for discovery, note that this may result in failures using the AWS Load Balancer controller. The Load Balancer controller only supports a single security group having that tag key. See [this issue](https://github.com/kubernetes-sigs/aws-load-balancer-controller/issues/2367) for more details. To verify if this restriction affects you, run the following commands. ```bash CLUSTER_VPC_ID="$(aws eks describe-cluster --name $CLUSTER_NAME --query cluster.resourcesVpcConfig.vpcId --output text)" aws ec2 describe-security-groups --filters Name=vpc-id,Values=$CLUSTER_VPC_ID Name=tag-key,Values=kubernetes.io/cluster/$CLUSTER_NAME --query 'SecurityGroups[].[GroupName]' --output text ``` If multiple securityGroups are printed, you will need more specific securityGroupSelectorTerms. We generally recommend that you use the `karpenter.sh/discovery: $CLUSTER_NAME` tag selector instead. {{% /alert %}} #### Examples Select all assigned to a cluster: ```yaml spec: securityGroupSelectorTerms: - tags: kubernetes.io/cluster/$CLUSTER_NAME: "owned" ``` Select all with a specified tag key: ```yaml spec: securityGroupSelectorTerms: - tags: MyTag: '*' ``` Select by name and tag (all criteria must match): ```yaml spec: securityGroupSelectorTerms: - name: my-security-group tags: MyTag: '*' # matches all resources with the tag ``` Select using multiple tag terms: ```yaml spec: securityGroupSelectorTerms: - tags: Name: "my-security-group-1" - tags: Name: "my-security-group-2" ``` Select by name using a wildcard: ```yaml spec: securityGroupSelectorTerms: - name: "*Public*" ``` Select using ids: ```yaml spec: securityGroupSelectorTerms: - id: "sg-063d7acfb4b06c82c" - id: "sg-06e0cf9c198874591" ``` ## spec.role `Role` is an optional field and tells Karpenter which IAM identity nodes should assume. You must specify one of `role` or `instanceProfile` when creating a Karpenter `EC2NodeClass`. If using the [Karpenter Getting Started Guide]({{<ref "../getting-started/getting-started-with-karpenter" >}}) to deploy Karpenter, you can use the `KarpenterNodeRole-$CLUSTER_NAME` role provisioned by that process. ```yaml spec: role: "KarpenterNodeRole-$CLUSTER_NAME" ``` ## spec.instanceProfile `InstanceProfile` is an optional field and tells Karpenter which IAM identity nodes should assume. You must specify one of `role` or `instanceProfile` when creating a Karpenter `EC2NodeClass`. If you use the `instanceProfile` field instead of `role`, Karpenter will not manage the InstanceProfile on your behalf; instead, it expects that you have pre-provisioned an IAM instance profile and assigned it a role. You can provision and assign a role to an IAM instance profile using [CloudFormation](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-iam-instanceprofile.html) or by using the [`aws iam create-instance-profile`](https://docs.aws.amazon.com/cli/latest/reference/iam/create-instance-profile.html) and [`aws iam add-role-to-instance-profile`](https://docs.aws.amazon.com/cli/latest/reference/iam/add-role-to-instance-profile.html) commands in the CLI. {{% alert title="Note" color="primary" %}} For [private clusters](https://docs.aws.amazon.com/eks/latest/userguide/private-clusters.html) that do not have access to the public internet, using `spec.instanceProfile` is required. `spec.role` cannot be used since Karpenter needs to access IAM endpoints to manage a generated instance profile. IAM [doesn't support private endpoints](https://docs.aws.amazon.com/vpc/latest/privatelink/aws-services-privatelink-support.html) to enable accessing the service without going to the public internet. {{% /alert %}} {{% alert title="Warning" color="warning" %}} When using `spec.instanceProfile`, ensure you are using pre-provisioned instance profiles that you manage yourself. {{% /alert %}} ## spec.amiSelectorTerms AMI Selector Terms are __required__ and are used to configure AMIs for Karpenter to use. AMIs are discovered through alias, id, owner, name, and [tags](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html). This selection logic is modeled as terms, where each term contains multiple conditions that must all be satisfied for the selector to match. Effectively, all requirements within a single term are ANDed together. It's possible that you may want to select on two different AMIs that have unrelated requirements. In this case, you can specify multiple terms which will be ORed together to form your selection logic. The example below shows how this selection logic is fulfilled. ```yaml amiSelectorTerms: # Select on any AMI that has both the `karpenter.sh/discovery: ${CLUSTER_NAME}` # AND `environment: test` tags OR any AMI with the name `my-ami` OR an AMI with # ID `ami-123` OR an AMI with ID matching the value of my-custom-parameter - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" environment: test - name: my-ami - id: ami-123 - ssmParameter: my-custom-parameter # ssm parameter name or ARN # Select EKS optimized AL2023 AMIs with version `v20240807`. This term is mutually # exclusive and can't be specified with other terms. # - alias: al2023@v20240807 ``` An `alias` term can be used to select EKS-optimized AMIs. An `alias` is formatted as `family@version`. Family can be one of the following values: * `al2` * `al2023` * `bottlerocket` * `windows2019` * `windows2022` The version string can be set to `latest`, or pinned to a specific AMI using the format of that AMI's GitHub release tags. For example, AL2 and AL2023 use dates for their release, so they can be pinned as follows: ```yaml alias: al2023@v20240703 ``` Bottlerocket uses a semantic version for their releases. You can pin bottlerocket as follows: ```yaml alias: bottlerocket@v1.20.4 ``` The Windows family does not support pinning, so only `latest` is supported. The following commands can be used to determine the versions availble for an alias in your region: {{< tabpane text=true right=false >}} {{% tab "AL2023" %}} ```bash export K8S_VERSION="1.34" aws ssm get-parameters-by-path --path "/aws/service/eks/optimized-ami/$K8S_VERSION/amazon-linux-2023/" --recursive | jq -cr '.Parameters[].Name' | grep -v "recommended" | awk -F '/' '{print $10}' | sed -r 's/.*(v[[:digit:]]+)$/\1/' | sort | uniq ``` {{% /tab %}} {{% tab "AL2" %}} ```bash export K8S_VERSION="1.34" aws ssm get-parameters-by-path --path "/aws/service/eks/optimized-ami/$K8S_VERSION/amazon-linux-2/" --recursive | jq -cr '.Parameters[].Name' | grep -v "recommended" | awk -F '/' '{print $8}' | sed -r 's/.*(v[[:digit:]]+)$/\1/' | sort | uniq ``` {{% /tab %}} {{% tab "Bottlerocket" %}} ```bash export K8S_VERSION="1.34" aws ssm get-parameters-by-path --path "/aws/service/bottlerocket/aws-k8s-$K8S_VERSION" --recursive | jq -cr '.Parameters[].Name' | grep -v "latest" | awk -F '/' '{print $7}' | sort | uniq ``` {{% /tab %}} {{< /tabpane >}} {{% alert title="Warning" color="warning" %}} Karpenter supports automatic AMI selection and upgrades using the `latest` version pin, but this is **not** recommended for production environments. When using `latest`, a new AMI release will cause Karpenter to drift all out-of-date nodes in the cluster, replacing them with nodes running the new AMI. We strongly recommend evaluating new AMIs in a lower environment before rolling them out into a production environment. More details on Karpenter's recommendations for managing AMIs can be found [here]({{< ref "../tasks/managing-amis" >}}). {{% /alert %}} To select an AMI by name, use the `name` field in the selector term. To select an AMI by id, use the `id` field in the selector term. To select AMIs that are not owned by `amazon` or the account that Karpenter is running in, use the `owner` field - you can use a combination of account aliases (e.g. `self` `amazon`, `your-aws-account-name`) and account IDs. If owner is not set for `name`, it defaults to `self,amazon`, preventing Karpenter from inadvertently selecting an AMI that is owned by a different account. Tags don't require an owner as tags can only be discovered by the user who created them. {{% alert title="Tip" color="secondary" %}} AMIs may be specified by any AWS tag, including `Name`. Selecting by tag or by name using wildcards (`*`) is supported. {{% /alert %}} {{% alert title="Note" color="primary" %}} If `amiSelectorTerms` match more than one AMI, Karpenter will automatically determine which AMI best fits the workloads on the launched worker node under the following constraints: * When launching nodes, Karpenter automatically determines which architecture a custom AMI is compatible with and will use images that match an instanceType's requirements. * Unless using an alias, Karpenter **cannot** detect requirements other than architecture. If you need to specify different AMIs for different kind of nodes (e.g. accelerated GPU AMIs), you should use a separate `EC2NodeClass`. * If multiple AMIs are found that can be used, Karpenter will choose the latest one. * If no AMIs are found that can be used, then no nodes will be provisioned. {{% /alert %}} #### Examples Select by AMI family and version: ```yaml amiSelectorTerms: - alias: al2023@v20240807 ``` Select all with a specified tag: ```yaml amiSelectorTerms: - tags: karpenter.sh/discovery/MyClusterName: '*' ``` Select by name: ```yaml amiSelectorTerms: - name: my-ami ``` Select by `Name` tag: ```yaml amiSelectorTerms: - tags: Name: my-ami ``` Select by name and owner: ```yaml amiSelectorTerms: - name: my-ami owner: self - name: my-ami owner: "0123456789" ``` Select by name using a wildcard: ```yaml spec: amiSelectorTerms: - name: "*EKS*" ``` Select by all under an owner: ```yaml spec: amiSelectorTerms: - name: "*" owner: self ``` Specify using ids: ```yaml amiSelectorTerms: - id: "ami-123" - id: "ami-456" ``` Specify using custom ssm parameter name or ARN: ```yaml amiSelectorTerms: - ssmParameter: "my-custom-parameter" ``` {{% alert title="Note" color="primary" %}} When using a custom SSM parameter, you'll need to expand the `ssm:GetParameter` permissions on the Karpenter IAM role to include your custom parameter, as the default policy only allows access to the AWS public parameters. {{% /alert %}} ## spec.capacityReservationSelectorTerms <i class="fa-solid fa-circle-info"></i> <b>Feature State: </b> [Beta]({{<ref "../reference/settings#feature-gates" >}}) Capacity Reservation Selector Terms allow you to select [on-demand capacity reservations](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-capacity-reservations.html) (ODCRs), which will be made available to NodePools which select the given EC2NodeClass. Karpenter will prioritize utilizing the capacity in these reservations before falling back to on-demand and spot. Capacity reservations can be discovered using ids, tags, or instance match criteria. This selection logic is modeled as terms. A term can specify an ID, a set of tags, or instance match criteria to select against. When specifying tags, it will select all capacity reservations accessible from the account with matching tags. When specifying instance match criteria, it selects reservations by their matching behavior: `open` (matches all compatible instances) or `targeted` (matches only explicitly targeted instances). This can be further restricted by specifying an owner ID. For more information on utilizing ODCRs with Karpenter, refer to the [Utilizing ODCRs Task]({{< relref "../tasks/odcrs" >}}). {{% alert title="Note" color="primary" %}} Note that the IAM role Karpenter assumes should have a permissions policy associated with it that grants it permissions to use the [ec2:DescribeCapacityReservations](https://docs.aws.amazon.com/service-authorization/latest/reference/list_amazonec2.html#amazonec2-DescribeCapacityReservations) action to discover capacity reservations and the [ec2:RunInstances](https://docs.aws.amazon.com/service-authorization/latest/reference/list_amazonec2.html#amazonec2-RunInstances) action to run instances in those capacity reservations. {{% /alert %}} #### Examples Select the reservations with the given IDs: ```yaml spec: capacityReservationSelectorTerms: - id: cr-123 - id: cr-456 ``` Select the reservations by tags: ```yaml spec: capacityReservationSelectorTerms: # Select all capacity reservations which have both matching tags - tags: key1: foo key2: bar # Additionally, select all capacity reservations with the following matching tag - tags: key3: foobar ``` Select by tags and owner ID: ```yaml spec: # Select all capacity reservations with the matching tags which are also owned by # the specified account. capacityReservationSelectorTerms: - tags: key: foo ownerID: 012345678901 ``` Select by instance match criteria: ```yaml spec: capacityReservationSelectorTerms: # Select all open capacity reservations - instanceMatchCriteria: open ``` Select by instance match criteria and tags: ```yaml spec: capacityReservationSelectorTerms: # Select targeted capacity reservations with matching tags - instanceMatchCriteria: targeted tags: key: foo ``` ## spec.tags Karpenter adds tags to all resources it creates, including EC2 Instances, EBS volumes, and Launch Templates. The default set of tags are listed below. ```yaml Name: <node-name> karpenter.sh/nodeclaim: <nodeclaim-name> karpenter.sh/nodepool: <nodepool-name> karpenter.k8s.aws/ec2nodeclass: <ec2nodeclass-name> kubernetes.io/cluster/<cluster-name>: owned eks:eks-cluster-name: <cluster-name> ``` Additional tags can be added in the tags section, which will be merged with the default tags specified above. ```yaml spec: tags: InternalAccountingTag: 1234 dev.corp.net/app: Calculator dev.corp.net/team: MyTeam ``` {{% alert title="Note" color="primary" %}} Karpenter allows overrides of the default "Name" tag but does not allow overrides to restricted domains (such as "karpenter.sh", "karpenter.k8s.aws", and "kubernetes.io/cluster"). This ensures that Karpenter is able to correctly auto-discover nodes that it owns. {{% /alert %}} ## spec.metadataOptions Control the exposure of [Instance Metadata Service](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html) on EC2 Instances launched by this EC2NodeClass using a generated launch template. Refer to [recommended, security best practices](https://aws.github.io/aws-eks-best-practices/security/docs/iam/#restrict-access-to-the-instance-profile-assigned-to-the-worker-node) for limiting exposure of Instance Metadata and User Data to pods. If metadataOptions are omitted from this EC2NodeClass, the following default settings are applied: ```yaml spec: metadataOptions: httpEndpoint: enabled httpProtocolIPv6: disabled httpPutResponseHopLimit: 1 httpTokens: required ``` ## spec.blockDeviceMappings The `blockDeviceMappings` field in an `EC2NodeClass` can be used to control the [Elastic Block Storage (EBS) volumes](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html#instance-block-device-mapping) that Karpenter attaches to provisioned nodes. Karpenter uses default block device mappings for the AMIFamily specified. For example, the `Bottlerocket` AMI Family defaults with two block device mappings, one for Bottlerocket's control volume and the other for container resources such as images and logs. ```yaml spec: blockDeviceMappings: - deviceName: /dev/xvda ebs: volumeSize: 100Gi volumeType: gp3 iops: 10000 encrypted: true kmsKeyID: "1234abcd-12ab-34cd-56ef-1234567890ab" deleteOnTermination: true throughput: 125 snapshotID: snap-0123456789 volumeInitializationRate: 100 ``` The following blockDeviceMapping defaults are used for each `AMIFamily` if no `blockDeviceMapping` overrides are specified in the `EC2NodeClass` ### AL2 ```yaml spec: blockDeviceMappings: - deviceName: /dev/xvda ebs: volumeSize: 20Gi volumeType: gp3 encrypted: true ``` ### AL2023 ```yaml spec: blockDeviceMappings: - deviceName: /dev/xvda ebs: volumeSize: 20Gi volumeType: gp3 encrypted: true ``` ### Bottlerocket ```yaml spec: blockDeviceMappings: # Root device - deviceName: /dev/xvda ebs: volumeSize: 4Gi volumeType: gp3 encrypted: true # Data device: Container resources such as images and logs - deviceName: /dev/xvdb ebs: volumeSize: 20Gi volumeType: gp3 encrypted: true ``` ### Windows2019/Windows2022 ```yaml spec: blockDeviceMappings: - deviceName: /dev/sda1 ebs: volumeSize: 50Gi volumeType: gp3 encrypted: true ``` ### Custom The `Custom` AMIFamily ships without any default `blockDeviceMappings`. ## spec.instanceStorePolicy The `instanceStorePolicy` field controls how [instance-store](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceStorage.html) volumes are handled. By default, Karpenter and Kubernetes will simply ignore them. ### RAID0 If you intend to use these volumes for faster node ephemeral-storage, set `instanceStorePolicy` to `RAID0`: ```yaml spec: instanceStorePolicy: RAID0 ``` This will set the allocatable ephemeral-storage of each node to the total size of the instance-store volume(s). This configuration is likely to be useful for workloads that leverage dense storage instance types or require the low latency from instance-stores that are nvme ssd based. The disks must be formatted & mounted in a RAID0 and be the underlying filesystem for the Kubelet & Containerd. Even if you already configure your volumes with RAID0, Karpenter won't recognize this by default unless you set the `instanceStorePolicy` to `RAID0`. Without this, scheduling workloads that depend on ephemeral-storage from the instance-stores may result in a deadlock due to insufficient storage. Instructions for each AMI family are listed below: #### AL2 On AL2, Karpenter automatically configures the disks through an additional boostrap argument (`--local-disks raid0`). The device name is `/dev/md/0` and its mount point is `/mnt/k8s-disks/0`. You should ensure any additional disk setup does not interfere with these. #### AL2023 On AL2023, Karpenter automatically configures the disks via the generated `NodeConfig` object. Like AL2, the device name is `/dev/md/0` and its mount point is `/mnt/k8s-disks/0`. You should ensure any additional disk setup does not interfere with these. #### Others For all other AMI families, you must configure the disks yourself. Check out the [`setup-local-disks`](https://github.com/awslabs/amazon-eks-ami/blob/main/templates/shared/runtime/bin/setup-local-disks) script in [amazon-eks-ami](https://github.com/awslabs/amazon-eks-ami) to see how this is done for AL2. {{% alert title="Tip" color="secondary" %}} Since the Kubelet & Containerd will be using the instance-store filesystem, you may consider using a more minimal root volume size. {{% /alert %}} ## spec.userData You can control the UserData that is applied to your worker nodes via this field. This allows you to run custom scripts or pass-through custom configuration to Karpenter instances on start-up. ```yaml apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass metadata: name: bottlerocket-example spec: ... amiFamily: Bottlerocket userData: | [settings.kubernetes] "kube-api-qps" = 30 "shutdown-grace-period" = "30s" "shutdown-grace-period-for-critical-pods" = "30s" [settings.kubernetes.eviction-hard] "memory.available" = "20%" ``` This example adds SSH keys to allow remote login to the node (replace *my-authorized_keys* with your public key file): {{% alert title="Note" color="primary" %}} Instead of using SSH as set up in this example, you can use Session Manager (SSM) or EC2 Instance Connect to gain shell access to Karpenter nodes. See [Node NotReady]({{< ref "../troubleshooting/#node-notready" >}}) troubleshooting for an example of starting an SSM session from the command line or [EC2 Instance Connect](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-connect-set-up.html) documentation to connect to nodes using SSH. Also, **my-authorized_key** key is the public key. See [Retrieve the public key material](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/describe-keys.html#retrieving-the-public-key). {{% /alert %}} ```yaml apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass metadata: name: al2-example spec: ... amiFamily: AL2 userData: | #!/bin/bash mkdir -p ~ec2-user/.ssh/ touch ~ec2-user/.ssh/authorized_keys cat >> ~ec2-user/.ssh/authorized_keys <<EOF {{ insertFile "../my-authorized_keys" | indent 4 }} EOF chmod -R go-w ~ec2-user/.ssh/authorized_keys chown -R ec2-user ~ec2-user/.ssh ``` Alternatively, you can save the [key in your SSM Parameter Store](https://docs.aws.amazon.com/systems-manager/latest/userguide/parameter-create-console.html) and use the get-parameter command mentioned below to retrieve the key for authorized_keys. ``` aws ssm get-parameter --name "<parameter-name>" --region <region> --with-decryption --query "Parameter.Value" --output text > /home/ec2-user/.ssh/authorized_keys ``` For more examples on configuring fields for different AMI families, see the [examples here](https://github.com/aws/karpenter/blob/main/examples/v1). Karpenter will merge the userData you specify with the default userData for that AMIFamily. See the [AMIFamily]({{< ref "#specamifamily" >}}) section for more details on these defaults. View the sections below to understand the different merge strategies for each AMIFamily. ### AL2 * Your UserData can be in the [MIME multi part archive](https://cloudinit.readthedocs.io/en/latest/topics/format.html#mime-multi-part-archive) format. * Karpenter will transform your custom user-data as a MIME part, if necessary, and then merge a final MIME part to the end of your UserData parts which will bootstrap the worker node. Karpenter will have full control over all the parameters being passed to the bootstrap script. * Karpenter will continue to set MaxPods, ClusterDNS and all other parameters defined in `spec.kubeletConfiguration` as before. Consider the following example to understand how your custom UserData will be merged - #### Passed-in UserData (bash) ```bash #!/bin/bash echo "Running custom user data script (bash)" ``` #### Merged UserData (bash) ```bash MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Running custom user data script (bash)" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash -xe exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1 /etc/eks/bootstrap.sh 'test-cluster' --apiserver-endpoint 'https://test-cluster' --b64-cluster-ca 'ca-bundle' \ --use-max-pods false \ --kubelet-extra-args '--node-labels=karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test --max-pods=110' --//-- ``` #### Passed-in UserData (MIME) ```bash MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="BOUNDARY" --BOUNDARY Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Running custom user data script (mime)" --BOUNDARY-- ``` #### Merged UserData (MIME) ```bash MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Running custom user data script (mime)" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash -xe exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1 /etc/eks/bootstrap.sh 'test-cluster' --apiserver-endpoint 'https://test-cluster' --b64-cluster-ca 'ca-bundle' \ --use-max-pods false \ --kubelet-extra-args '--node-labels=karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=test --max-pods=110' --//-- ``` {{% alert title="Tip" color="secondary" %}} You can set additional kubelet configuration properties, unavailable through `spec.kubelet`, by updating the `kubelet-config.json` file: ```yaml apiVersion: karpenter.k8s.aws/v1 kind: EC2NodeClass metadata: name: kubelet-config-example spec: amiFamily: AL2 userData: | #!/bin/bash echo "$(jq '.kubeAPIQPS=50' /etc/kubernetes/kubelet/kubelet-config.json)" > /etc/kubernetes/kubelet/kubelet-config.json ``` {{% /alert %}} ### AL2023 * Your UserData may be in one of three formats: a [MIME multi part archive](https://cloudinit.readthedocs.io/en/latest/topics/format.html#mime-multi-part-archive), a NodeConfig YAML / JSON string, or a shell script. * Karpenter will transform your custom UserData into a MIME part, if necessary, and then create a MIME multi-part archive. This archive will consist of a generated NodeConfig, containing Karpenter's default values, followed by the transformed custom UserData. For more information on the NodeConfig spec, refer to the [AL2023 EKS Optimized AMI docs](https://awslabs.github.io/amazon-eks-ami/nodeadm/doc/examples/). {{% alert title="Warning" color="warning" %}} Any values configured by the Karpenter generated NodeConfig object will take precedent over values specifed in `spec.userData`. This includes cluster name, cluster CIDR, cluster endpoint, certificate authority, taints, labels, and any value in [spec.kubelet]({{< ref "#speckubelet" >}}). These fields must be configured natively through Karpenter rather than through UserData. {{% /alert %}} #### Passed-in UserData (NodeConfig) ```yaml apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: kubelet: config: maxPods: 42 ``` #### Merged UserData (NodeConfig) ```text MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: application/node.eks.aws apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: kubelet: config: maxPods: 42 --// Content-Type: application/node.eks.aws # Karpenter Generated NodeConfig apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: cluster: apiServerEndpoint: https://test-cluster certificateAuthority: cluster-ca cidr: 10.100.0.0/16 name: test-cluster kubelet: config: clusterDNS: - 10.100.0.10 maxPods: 118 flags: - --node-labels="karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=default" --//-- ``` #### Passed-in UserData (bash) ```shell #!/bin/bash echo "Hello, AL2023!" ``` #### Merged UserData (bash) ```text MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Hello, AL2023!" --// Content-Type: application/node.eks.aws # Karpenter Generated NodeConfig apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: cluster: apiServerEndpoint: https://test-cluster certificateAuthority: cluster-ca cidr: 10.100.0.0/16 name: test-cluster kubelet: config: clusterDNS: - 10.100.0.10 maxPods: 118 flags: - --node-labels="karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=default" --//-- ``` #### Passed-in UserData (MIME) ```text MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Hello, AL2023!" --// Content-Type: application/node.eks.aws apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: kubelet: config: maxPods: 42 --// ``` #### Merged UserData (MIME) ```text MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="//" --// Content-Type: application/node.eks.aws apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: kubelet: config: maxPods: 42 --// Content-Type: text/x-shellscript; charset="us-ascii" #!/bin/bash echo "Hello, AL2023!" --// Content-Type: application/node.eks.aws # Karpenter Generated NodeConfig apiVersion: node.eks.aws/v1alpha1 kind: NodeConfig spec: cluster: apiServerEndpoint: https://test-cluster certificateAuthority: cluster-ca cidr: 10.100.0.0/16 name: test-cluster kubelet: config: clusterDNS: - 10.100.0.10 maxPods: 118 flags: - --node-labels="karpenter.sh/capacity-type=on-demand,karpenter.sh/nodepool=default" --//-- ``` ### Bottlerocket * Your UserData must be valid TOML. * Unknown TOML fields will be ignored when the final merged UserData is generated by Karpenter. {{% alert title="Warning" color="warning" %}} Any values configured by Karpenter will take precedent over values specifed in `spec.userData`. This includes cluster name, cluster endpoint, cluster certificate, taints, labels, and any value in [spec.kubelet]({{< ref "#speckubelet" >}}). These fields must be configured natively through Karpenter rather than through UserData. {{% /alert %}} Consider the following example to understand how your custom UserData settings will be merged in. #### Passed-in UserData ```toml [settings.kubernetes.eviction-hard] "memory.available" = "12%" [settings.kubernetes] "unknown-setting" = "unknown" [settings.kubernetes.node-labels] 'field.controlled.by/karpenter' = 'will-be-overridden' ``` #### Merged UserData ```toml [settings] [settings.kubernetes] api-server = 'https://cluster' cluster-certificate = 'ca-bundle' cluster-name = 'cluster' [settings.kubernetes.node-labels] 'karpenter.sh/capacity-type' = 'on-demand' 'karpenter.sh/nodepool' = 'default' [settings.kubernetes.node-taints] [settings.kubernetes.eviction-hard] 'memory.available' = '12%%' ``` #### Device ownership in Bottlerocket Bottlerocket `v1.30.0+` supports device ownership using the [security context](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/) provided in the Kubernetes specfile. To enable this, you will need the following user-data configurations: ```toml [settings] [settings.kubernetes] device-ownership-from-security-context = true ``` This allows the container to take ownership of devices allocated to the pod via device-plugins based on the `runAsUser` and `runAsGroup` values provided in the spec. For more details on this, see the [Kubernetes documentation](https://kubernetes.io/blog/2021/11/09/non-root-containers-and-devices/) This setting helps you enable Neuron workloads on Bottlerocket instances. See [Accelerators/GPU Resources]({{< ref "./scheduling#acceleratorsgpu-resources" >}}) for more details. ### Windows2019/Windows2022 * Your UserData must be specified as PowerShell commands. * The UserData specified will be prepended to a Karpenter managed section that will bootstrap the kubelet. * Karpenter will continue to set ClusterDNS and all other parameters defined in spec.kubeletConfiguration as before. Consider the following example to understand how your custom UserData settings will be merged in. #### Passed-in UserData ```powershell Write-Host "Running custom user data script" ``` #### Merged UserData ```powershell <powershell> Write-Host "Running custom user data script" [string]$EKSBootstrapScriptFile = "$env:ProgramFiles\Amazon\EKS\Start-EKSBootstrap.ps1" & $EKSBootstrapScriptFile -EKSClusterName 'test-cluster' -APIServerEndpoint 'https://test-cluster' -Base64ClusterCA 'ca-bundle' -KubeletExtraArgs '--node-labels="karpenter.sh/capacity-type=spot,karpenter.sh/nodepool=windows2022" --max-pods=110' -DNSClusterIP '10.0.100.10' </powershell> ``` {{% alert title="Windows Support Notice" color="warning" %}} Currently, Karpenter does not specify `-ServiceCIDR` to [EKS Windows AMI Bootstrap script](https://docs.aws.amazon.com/eks/latest/userguide/eks-optimized-windows-ami.html#bootstrap-script-configuration-parameters). Windows worker nodes will use `172.20.0.0/16` or `10.100.0.0/16` for Kubernetes service IP address ranges based on the IP address of the primary interface. The effective ServiceCIDR can be verified at `$env:ProgramData\Amazon\EKS\cni\config\vpc-bridge.conf` on the worker node. Support for the Windows ServiceCIDR argument can be tracked in a [Karpenter Github Issue](https://github.com/aws/karpenter/issues/4088). Currently, if the effective ServiceCIDR is incorrect for your windows worker nodes, you can add the following userData as a workaround. ```yaml spec: userData: | $global:EKSCluster = Get-EKSCluster -Name my-cluster ``` {{% /alert %}} ### Custom * No merging is performed, your UserData must perform all setup required of the node to allow it to join the cluster. * Custom UserData must meet the following requirements to work correctly with Karpenter: * It must ensure the node is registered with the `karpenter.sh/unregistered:NoExecute` taint (via kubelet configuration field `registerWithTaints`) * It must set kubelet config options to match those configured in `spec.kubelet` ## spec.detailedMonitoring Enabling detailed monitoring controls the [EC2 detailed monitoring](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-cloudwatch-new.html) feature. If you enable this option, the Amazon EC2 console displays monitoring graphs with a 1-minute period for the instances that Karpenter launches. ```yaml spec: detailedMonitoring: true ``` ## spec.associatePublicIPAddress You can explicitly set `AssociatePublicIPAddress: false` when you are only launching into private subnets. Previously, Karpenter auto-set `associatePublicIPAddress` on the primary ENI to false if a user’s subnet options were all private subnets. This value is a boolean field that controls whether instances created by Karpenter for this EC2NodeClass will have an associated public IP address. This overrides the `MapPublicIpOnLaunch` setting applied to the subnet the node is launched in. If this field is not set, the `MapPublicIpOnLaunch` field will be respected. {{% alert title="Note" color="warning" %}} If a `NodeClaim` requests `vpc.amazonaws.com/efa` resources, `spec.associatePublicIPAddress` is respected. However, if this `NodeClaim` requests **multiple** EFA resources and the value for `spec.associatePublicIPAddress` is true, the instance will fail to launch. This is due to an EC2 restriction which requires that the field is only set to true when configuring an instance with a single ENI at launch. When using this field, it is advised that users segregate their EFA workload to use a separate `NodePool` / `EC2NodeClass` pair. {{% /alert %}} ## spec.ipPrefixCount This value is a integer field that controls how many ip prefixes will be assigned to `NodeClaim`. See the [EC2 Launch Template Network Interface Spec](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-properties-ec2-launchtemplate-networkinterface.html) for more information. Sets ipv4PrefixCount if you are using an IPv4 Cluster, or ipv6PrefixCount if you are using IPv6. ## status.subnets [`status.subnets`]({{< ref "#statussubnets" >}}) contains the resolved `id` and `zone` of the subnets that were selected by the [`spec.subnetSelectorTerms`]({{< ref "#specsubnetselectorterms" >}}) for the node class. The subnets will be sorted by the available IP address count in decreasing order. #### Examples ```yaml spec: subnetSelectorTerms: - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" status: subnets: - id: subnet-0a462d98193ff9fac zone: us-east-2b - id: subnet-0322dfafd76a609b6 zone: us-east-2c - id: subnet-0727ef01daf4ac9fe zone: us-east-2b - id: subnet-00c99aeafe2a70304 zone: us-east-2a - id: subnet-023b232fd5eb0028e zone: us-east-2c - id: subnet-03941e7ad6afeaa72 zone: us-east-2a ``` ## status.securityGroups [`status.securityGroups`]({{< ref "#statussecuritygroups" >}}) contains the resolved `id` and `name` of the security groups that were selected by the [`spec.securityGroupSelectorTerms`]({{< ref "#specsecuritygroupselectorterms" >}}) for the node class. The subnets will be sorted by the available IP address count in decreasing order. #### Examples ```yaml spec: securityGroupSelectorTerms: - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" status: securityGroups: - id: sg-041513b454818610b name: ClusterSharedNodeSecurityGroup - id: sg-0286715698b894bca name: ControlPlaneSecurityGroup-1AQ073TSAAPW ``` ## status.amis [`status.amis`]({{< ref "#statusamis" >}}) contains the resolved `id`, `name`, `requirements`, and the `deprecated` status of either the default AMIs for the [`spec.amiFamily`]({{< ref "#specamifamily" >}}) or the AMIs selected by the [`spec.amiSelectorTerms`]({{< ref "#specamiselectorterms" >}}) if this field is specified. The `deprecated` status will be shown for resolved AMIs that are deprecated. #### Examples AMIs resolved with an AL2 alias: ```yaml spec: amiSelectorTerms: - alias: al2@v20240807 status: amis: - id: ami-03c3a3dcda64f5b75 name: amazon-linux-2-gpu requirements: - key: kubernetes.io/arch operator: In values: - amd64 - key: karpenter.k8s.aws/instance-gpu-count operator: Exists - id: ami-03c3a3dcda64f5b75 name: amazon-linux-2-gpu requirements: - key: kubernetes.io/arch operator: In values: - amd64 - key: karpenter.k8s.aws/instance-accelerator-count operator: Exists - id: ami-06afb2d101cc4b8bd name: amazon-linux-2-arm64 requirements: - key: kubernetes.io/arch operator: In values: - arm64 - key: karpenter.k8s.aws/instance-gpu-count operator: DoesNotExist - key: karpenter.k8s.aws/instance-accelerator-count operator: DoesNotExist - id: ami-0e28b76d768af234e name: amazon-linux-2 requirements: - key: kubernetes.io/arch operator: In values: - amd64 - key: karpenter.k8s.aws/instance-gpu-count operator: DoesNotExist - key: karpenter.k8s.aws/instance-accelerator-count operator: DoesNotExist ``` AMIs resolved from tags: ```yaml spec: amiSelectorTerms: - tags: karpenter.sh/discovery: "${CLUSTER_NAME}" status: amis: - id: ami-01234567890123456 name: custom-ami-amd64 deprecated: true requirements: - key: kubernetes.io/arch operator: In values: - amd64 - id: ami-01234567890123456 name: custom-ami-arm64 requirements: - key: kubernetes.io/arch operator: In values: - arm64 ``` ## status.capacityReservations [`status.capacityReservations`]({{< ref "#statuscapacityreservations" >}}) contains the following information for each resolved capacity reservation: | Field | Example | Description | | ----------------------- | ---------------------- | ------------------------------------------------------------------------------------ | | `availabilityZone` | `us-east-1a` | The availability zone the capacity reservation is available in | | `id` | `cr-56fac701cc1951b03` | The ID of the capacity reservation | | `instanceMatchCriteria` | `open` | The instanceMatchCriteria for the capacity reservation. Can be `open` or `targeted`. | | `instanceType` | `m5.large` | The EC2 instance type of the capacity reservation | | `ownerID` | `459763720645` | The account ID that owns the capacity reservation | | `reservationType` | `default` | The type of the capacity reservation. Can be `default` or `capacity-block`. | | `state` | `active` | The state of the capacity reservation. Can be `active` or `expiring`. | #### Examples ```yaml status: capacityReservations: - availabilityZone: us-west-2a id: cr-01234567890123456 instanceMatchCriteria: targeted instanceType: g6.48xlarge ownerID: "012345678901" reservationType: capacity-block state: expiring - availabilityZone: us-west-2c id: cr-12345678901234567 instanceMatchCriteria: open instanceType: g6.48xlarge ownerID: "98765432109" reservationType: default state: active ``` ## status.instanceProfile [`status.instanceProfile`]({{< ref "#statusinstanceprofile" >}}) contains the resolved instance profile generated by Karpenter from the [`spec.role`]({{< ref "#specrole" >}}) ```yaml spec: role: "KarpenterNodeRole-${CLUSTER_NAME}" status: instanceProfile: "${CLUSTER_NAME}-0123456778901234567789" ``` ## status.conditions [`status.conditions`]({{< ref "#statusconditions" >}}) indicates EC2NodeClass readiness. This will be `Ready` when Karpenter successfully discovers AMIs, Instance Profile, Subnets, Cluster CIDR (AL2023 only) and SecurityGroups for the EC2NodeClass. NodeClasses have the following status conditions: | Condition Type | Description | |----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | SubnetsReady | Subnets are discovered. | | SecurityGroupsReady | Security Groups are discovered. | | InstanceProfileReady | Instance Profile is discovered. | | AMIsReady | AMIs are discovered. | | Ready | Top level condition that indicates if the nodeClass is ready. If any of the underlying conditions is `False` then this condition is set to `False` and `Message` on the condition indicates the dependency that was not resolved. | If a NodeClass is not ready, NodePools that reference it through their `nodeClassRef` will not be considered for scheduling.