The CDK Construct Library for AWS::EKS
Project description
Amazon EKS Construct Library
---This is a developer preview (public beta) module.
All classes with the
Cfn
prefix in this module (CFN Resources) are auto-generated from CloudFormation. They are stable and safe to use.However, all other classes, i.e., higher level constructs, are under active development and subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.
This construct library allows you to define Amazon Elastic Container Service for Kubernetes (EKS) clusters programmatically. This library also supports programmatically defining Kubernetes resource manifests within EKS clusters.
This example defines an Amazon EKS cluster with the following configuration:
- Managed nodegroup with 2x m5.large instances (this instance type suits most common use-cases, and is good value for money)
- Dedicated VPC with default configuration (see ec2.Vpc)
- A Kubernetes pod with a container based on the paulbouwer/hello-kubernetes image.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster = eks.Cluster(self, "hello-eks")
cluster.add_resource("mypod",
api_version="v1",
kind="Pod",
metadata={"name": "mypod"},
spec={
"containers": [{
"name": "hello",
"image": "paulbouwer/hello-kubernetes:1.5",
"ports": [{"container_port": 8080}]
}
]
}
)
Capacity
By default, eks.Cluster
is created with a managed nodegroup with x2 m5.large
instances.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
eks.Cluster(self, "cluster-two-m5-large")
To use the traditional self-managed Amazon EC2 instances instead, set defaultCapacityType
to DefaultCapacityType.EC2
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster = eks.Cluster(self, "cluster-self-managed-ec2",
default_capacity_type=eks.DefaultCapacityType.EC2
)
The quantity and instance type for the default capacity can be specified through
the defaultCapacity
and defaultCapacityInstance
props:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
eks.Cluster(self, "cluster",
default_capacity=10,
default_capacity_instance=ec2.InstanceType("m2.xlarge")
)
To disable the default capacity, simply set defaultCapacity
to 0
:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
eks.Cluster(self, "cluster-with-no-capacity", default_capacity=0)
The cluster.defaultCapacity
property will reference the AutoScalingGroup
resource for the default capacity. It will be undefined
if defaultCapacity
is set to 0
or defaultCapacityType
is either NODEGROUP
or undefined.
And the cluster.defaultNodegroup
property will reference the Nodegroup
resource for the default capacity. It will be undefined
if defaultCapacity
is set to 0
or defaultCapacityType
is EC2
.
You can add AutoScalingGroup
resource as customized capacity through cluster.addCapacity()
or
cluster.addAutoScalingGroup()
:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster.add_capacity("frontend-nodes",
instance_type=ec2.InstanceType("t2.medium"),
min_capacity=3,
vpc_subnets={"subnet_type": ec2.SubnetType.PUBLIC}
)
Managed Node Groups
Amazon EKS managed node groups automate the provisioning and lifecycle management of nodes (Amazon EC2 instances)
for Amazon EKS Kubernetes clusters. By default, eks.Nodegroup
create a nodegroup with x2 t3.medium
instances.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
eks.Nodegroup(stack, "nodegroup", cluster=cluster)
You can add customized node group through cluster.addNodegroup()
:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster.add_nodegroup("nodegroup",
instance_type=ec2.InstanceType("m5.large"),
min_size=4
)
Fargate
AWS Fargate is a technology that provides on-demand, right-sized compute capacity for containers. With AWS Fargate, you no longer have to provision, configure, or scale groups of virtual machines to run containers. This removes the need to choose server types, decide when to scale your node groups, or optimize cluster packing.
You can control which pods start on Fargate and how they run with Fargate Profiles, which are defined as part of your Amazon EKS cluster.
See Fargate Considerations in the AWS EKS User Guide.
You can add Fargate Profiles to any EKS cluster defined in your CDK app
through the addFargateProfile()
method. The following example adds a profile
that will match all pods from the "default" namespace:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster.add_fargate_profile("MyProfile",
selectors=[{"namespace": "default"}]
)
To create an EKS cluster that only uses Fargate capacity, you can use
FargateCluster
.
The following code defines an Amazon EKS cluster without EC2 capacity and a default
Fargate Profile that matches all pods from the "kube-system" and "default" namespaces. It is also configured to run CoreDNS on Fargate through the coreDnsComputeType
cluster option.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster = eks.FargateCluster(self, "MyCluster")
# apply k8s resources on this cluster
cluster.add_resource(...)
NOTE: Classic Load Balancers and Network Load Balancers are not supported on pods running on Fargate. For ingress, we recommend that you use the ALB Ingress Controller on Amazon EKS (minimum version v1.1.4).
Spot Capacity
If spotPrice
is specified, the capacity will be purchased from spot instances:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster.add_capacity("spot",
spot_price="0.1094",
instance_type=ec2.InstanceType("t3.large"),
max_capacity=10
)
Spot instance nodes will be labeled with lifecycle=Ec2Spot
and tainted with PreferNoSchedule
.
The Spot Termination Handler DaemonSet will be installed on these nodes. The termination handler leverages EC2 Spot Instance Termination Notices to gracefully stop all pods running on spot nodes that are about to be terminated.
Bootstrapping
When adding capacity, you can specify options for
/etc/eks/boostrap.sh
which is responsible for associating the node to the EKS cluster. For example,
you can use kubeletExtraArgs
to add custom node labels or taints.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
# up to ten spot instances
cluster.add_capacity("spot",
instance_type=ec2.InstanceType("t3.large"),
min_capacity=2,
bootstrap_options={
"kubelet_extra_args": "--node-labels foo=bar,goo=far",
"aws_api_retry_attempts": 5
}
)
To disable bootstrapping altogether (i.e. to fully customize user-data), set bootstrapEnabled
to false
when you add
the capacity.
Masters Role
The Amazon EKS construct library allows you to specify an IAM role that will be
granted system:masters
privileges on your cluster.
Without specifying a mastersRole
, you will not be able to interact manually
with the cluster.
The following example defines an IAM role that can be assumed by all users
in the account and shows how to use the mastersRole
property to map this
role to the Kubernetes system:masters
group:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
# first define the role
cluster_admin = iam.Role(self, "AdminRole",
assumed_by=iam.AccountRootPrincipal()
)
# now define the cluster and map role to "masters" RBAC group
eks.Cluster(self, "Cluster",
masters_role=cluster_admin
)
When you cdk deploy
this CDK app, you will notice that an output will be printed
with the update-kubeconfig
command.
Something like this:
Outputs:
eks-integ-defaults.ClusterConfigCommand43AAE40F = aws eks update-kubeconfig --name cluster-ba7c166b-c4f3-421c-bf8a-6812e4036a33 --role-arn arn:aws:iam::112233445566:role/eks-integ-defaults-Role1ABCC5F0-1EFK2W5ZJD98Y
Copy & paste the "aws eks update-kubeconfig ...
" command to your shell in
order to connect to your EKS cluster with the "masters" role.
Now, given AWS CLI is configured to use AWS
credentials for a user that is trusted by the masters role, you should be able
to interact with your cluster through kubectl
(the above example will trust
all users in the account).
For example:
$ aws eks update-kubeconfig --name cluster-ba7c166b-c4f3-421c-bf8a-6812e4036a33 --role-arn arn:aws:iam::112233445566:role/eks-integ-defaults-Role1ABCC5F0-1EFK2W5ZJD98Y
Added new context arn:aws:eks:eu-west-2:112233445566:cluster/cluster-ba7c166b-c4f3-421c-bf8a-6812e4036a33 to /Users/boom/.kube/config
$ kubectl get nodes # list all nodes
NAME STATUS ROLES AGE VERSION
ip-10-0-147-66.eu-west-2.compute.internal Ready <none> 21m v1.13.7-eks-c57ff8
ip-10-0-169-151.eu-west-2.compute.internal Ready <none> 21m v1.13.7-eks-c57ff8
$ kubectl get all -n kube-system
NAME READY STATUS RESTARTS AGE
pod/aws-node-fpmwv 1/1 Running 0 21m
pod/aws-node-m9htf 1/1 Running 0 21m
pod/coredns-5cb4fb54c7-q222j 1/1 Running 0 23m
pod/coredns-5cb4fb54c7-v9nxx 1/1 Running 0 23m
pod/kube-proxy-d4jrh 1/1 Running 0 21m
pod/kube-proxy-q7hh7 1/1 Running 0 21m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kube-dns ClusterIP 172.20.0.10 <none> 53/UDP,53/TCP 23m
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/aws-node 2 2 2 2 2 <none> 23m
daemonset.apps/kube-proxy 2 2 2 2 2 <none> 23m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/coredns 2/2 2 2 23m
NAME DESIRED CURRENT READY AGE
replicaset.apps/coredns-5cb4fb54c7 2 2 2 23m
For your convenience, an AWS CloudFormation output will automatically be
included in your template and will be printed when running cdk deploy
.
NOTE: if the cluster is configured with kubectlEnabled: false
, it
will be created with the role/user that created the AWS CloudFormation
stack. See Kubectl Support for details.
Kubernetes Resources
The KubernetesResource
construct or cluster.addResource
method can be used
to apply Kubernetes resource manifests to this cluster.
The following examples will deploy the paulbouwer/hello-kubernetes service on the cluster:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
app_label = {"app": "hello-kubernetes"}
deployment = {
"api_version": "apps/v1",
"kind": "Deployment",
"metadata": {"name": "hello-kubernetes"},
"spec": {
"replicas": 3,
"selector": {"match_labels": app_label},
"template": {
"metadata": {"labels": app_label},
"spec": {
"containers": [{
"name": "hello-kubernetes",
"image": "paulbouwer/hello-kubernetes:1.5",
"ports": [{"container_port": 8080}]
}
]
}
}
}
}
service = {
"api_version": "v1",
"kind": "Service",
"metadata": {"name": "hello-kubernetes"},
"spec": {
"type": "LoadBalancer",
"ports": [{"port": 80, "target_port": 8080}],
"selector": app_label
}
}
# option 1: use a construct
KubernetesResource(self, "hello-kub",
cluster=cluster,
manifest=[deployment, service]
)
# or, option2: use `addResource`
cluster.add_resource("hello-kub", service, deployment)
Since Kubernetes resources are implemented as CloudFormation resources in the
CDK. This means that if the resource is deleted from your code (or the stack is
deleted), the next cdk deploy
will issue a kubectl delete
command and the
Kubernetes resources will be deleted.
Patching Kubernetes Resources
The KubernetesPatch construct can be used to update existing kubernetes
resources. The following example can be used to patch the hello-kubernetes
deployment from the example above with 5 replicas.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
KubernetesPatch(self, "hello-kub-deployment-label",
cluster=cluster,
resource_name="deployment/hello-kubernetes",
apply_patch={"spec": {"replicas": 5}},
restore_patch={"spec": {"replicas": 3}}
)
AWS IAM Mapping
As described in the Amazon EKS User Guide, you can map AWS IAM users and roles to Kubernetes Role-based access control (RBAC).
The Amazon EKS construct manages the aws-auth ConfigMap Kubernetes resource
on your behalf and exposes an API through the cluster.awsAuth
for mapping
users, roles and accounts.
Furthermore, when auto-scaling capacity is added to the cluster (through
cluster.addCapacity
or cluster.addAutoScalingGroup
), the IAM instance role
of the auto-scaling group will be automatically mapped to RBAC so nodes can
connect to the cluster. No manual mapping is required any longer.
NOTE:
cluster.awsAuth
will throw an error if your cluster is created withkubectlEnabled: false
.
For example, let's say you want to grant an IAM user administrative privileges on your cluster:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
admin_user = iam.User(self, "Admin")
cluster.aws_auth.add_user_mapping(admin_user, groups=["system:masters"])
A convenience method for mapping a role to the system:masters
group is also available:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
cluster.aws_auth.add_masters_role(role)
Node ssh Access
If you want to be able to SSH into your worker nodes, you must already have an SSH key in the region you're connecting to and pass it, and you must be able to connect to the hosts (meaning they must have a public IP and you should be allowed to connect to them on port 22):
# Example automatically generated. See https://github.com/aws/jsii/issues/826
asg = cluster.add_capacity("Nodes",
instance_type=ec2.InstanceType("t2.medium"),
vpc_subnets=SubnetSelection(subnet_type=ec2.SubnetType.PUBLIC),
key_name="my-key-name"
)
# Replace with desired IP
asg.connections.allow_from(ec2.Peer.ipv4("1.2.3.4/32"), ec2.Port.tcp(22))
If you want to SSH into nodes in a private subnet, you should set up a bastion host in a public subnet. That setup is recommended, but is unfortunately beyond the scope of this documentation.
kubectl Support
When you create an Amazon EKS cluster, the IAM entity user or role, such as a
federated user
that creates the cluster, is automatically granted system:masters
permissions
in the cluster's RBAC configuration.
In order to allow programmatically defining Kubernetes resources in your AWS
CDK app and provisioning them through AWS CloudFormation, we will need to assume
this "masters" role every time we want to issue kubectl
operations against your
cluster.
At the moment, the AWS::EKS::Cluster
AWS CloudFormation resource does not support this behavior, so in order to
support "programmatic kubectl", such as applying manifests
and mapping IAM roles from within your CDK application, the Amazon EKS
construct library uses a custom resource for provisioning the cluster.
This custom resource is executed with an IAM role that we can then use
to issue kubectl
commands.
The default behavior of this library is to use this custom resource in order to retain programmatic control over the cluster. In other words: to allow you to define Kubernetes resources in your CDK code instead of having to manage your Kubernetes applications through a separate system.
One of the implications of this design is that, by default, the user who
provisioned the AWS CloudFormation stack (executed cdk deploy
) will
not have administrative privileges on the EKS cluster.
- Additional resources will be synthesized into your template (the AWS Lambda function, the role and policy).
- As described in Interacting with Your Cluster,
if you wish to be able to manually interact with your cluster, you will need
to map an IAM role or user to the
system:masters
group. This can be either done by specifying amastersRole
when the cluster is defined, callingcluster.awsAuth.addMastersRole
or explicitly mapping an IAM role or IAM user to the relevant Kubernetes RBAC groups usingcluster.addRoleMapping
and/orcluster.addUserMapping
.
If you wish to disable the programmatic kubectl behavior and use the standard
AWS::EKS::Cluster resource, you can specify kubectlEnabled: false
when you define
the cluster:
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
eks.Cluster(self, "cluster",
kubectl_enabled=False
)
Take care: a change in this property will cause the cluster to be destroyed and a new cluster to be created.
When kubectl is disabled, you should be aware of the following:
- When you log-in to your cluster, you don't need to specify
--role-arn
as long as you are using the same user that created the cluster. - As described in the Amazon EKS User Guide, you will need to manually edit the aws-auth ConfigMap when you add capacity in order to map the IAM instance role to RBAC to allow nodes to join the cluster.
- Any
eks.Cluster
APIs that depend on programmatic kubectl support will fail with an error:cluster.addResource
,cluster.addChart
,cluster.awsAuth
,props.mastersRole
.
Helm Charts
The HelmChart
construct or cluster.addChart
method can be used
to add Kubernetes resources to this cluster using Helm.
The following example will install the NGINX Ingress Controller to you cluster using Helm.
# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
# option 1: use a construct
HelmChart(self, "NginxIngress",
cluster=cluster,
chart="nginx-ingress",
repository="https://helm.nginx.com/stable",
namespace="kube-system"
)
# or, option2: use `addChart`
cluster.add_chart("NginxIngress",
chart="nginx-ingress",
repository="https://helm.nginx.com/stable",
namespace="kube-system"
)
Helm charts will be installed and updated using helm upgrade --install
.
This means that if the chart is added to CDK with the same release name, it will try to update
the chart in the cluster. The chart will exists as CloudFormation resource.
Helm charts are implemented as CloudFormation resources in CDK.
This means that if the chart is deleted from your code (or the stack is
deleted), the next cdk deploy
will issue a helm uninstall
command and the
Helm chart will be deleted.
When there is no release
defined, the chart will be installed using the node.uniqueId
,
which will be lower cassed and truncated to the last 63 characters.
Roadmap
- AutoScaling (combine EC2 and Kubernetes scaling)
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Source Distribution
Built Distribution
Hashes for aws_cdk.aws_eks-1.32.1-py3-none-any.whl
Algorithm | Hash digest | |
---|---|---|
SHA256 | 657aa7daf68dccdda26565852b38f6bea6c9afcaa0d57bb82ccccf41e66573b0 |
|
MD5 | 3f3dd3d28ef5fd1603a5abefa14fade2 |
|
BLAKE2b-256 | c0448f2f21984fae53375aa12b61c98bb536f476695a74984528170a90b25bc9 |