aws-cdk.aws-eks-legacy 1.204.0

Description:

awscdk.awsekslegacy 1.204.0

Amazon EKS Construct Library
---


This API may emit warnings. Backward compatibility is not guaranteed.



**This module is available for backwards compatibility purposes only (details). It will
no longer be released with the CDK starting March 1st, 2020. See [issue
5544](https://github.com/aws/aws-cdk/issues/5544) for upgrade instructions.**

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:

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.

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}]
}
]
}
})

Here is a complete sample.
Capacity
By default, eks.Cluster is created with x2 m5.large instances.
eks.Cluster(self, "cluster-two-m5-large")

The quantity and instance type for the default capacity can be specified through
the defaultCapacity and defaultCapacityInstance props:
eks.Cluster(self, "cluster",
default_capacity=10,
default_capacity_instance=ec2.InstanceType("m2.xlarge")
)

To disable the default capacity, simply set defaultCapacity to 0:
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:
cluster = eks.Cluster(self, "my-cluster")
cluster.default_capacity.scale_on_cpu_utilization("up",
target_utilization_percent=80
)

You can add customized capacity through cluster.addCapacity() or
cluster.addAutoScalingGroup():
# cluster: eks.Cluster

cluster.add_capacity("frontend-nodes",
instance_type=ec2.InstanceType("t2.medium"),
desired_capacity=3,
vpc_subnets=ec2.SubnetSelection(subnet_type=ec2.SubnetType.PUBLIC)
)

Spot Capacity
If spotPrice is specified, the capacity will be purchased from spot instances:
# cluster: eks.Cluster

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.
# up to ten spot instances
# cluster: eks.Cluster

cluster.add_capacity("spot",
instance_type=ec2.InstanceType("t3.large"),
desired_capacity=2,
bootstrap_options=eks.BootstrapOptions(
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:
# 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:
# cluster: eks.Cluster
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
eks.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.
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 with kubectlEnabled: false.

For example, let's say you want to grant an IAM user administrative privileges
on your cluster:
# cluster: eks.Cluster

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:
# cluster: eks.Cluster
# role: iam.Role

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):
asg = cluster.add_capacity("Nodes",
instance_type=ec2.InstanceType("t2.medium"),
vpc_subnets=ec2.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 a mastersRole when the cluster is defined, calling
cluster.awsAuth.addMastersRole or explicitly mapping an IAM role or IAM user to the
relevant Kubernetes RBAC groups using cluster.addRoleMapping and/or
cluster.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:
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.
# cluster: eks.Cluster

# option 1: use a construct
eks.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 with a unique name allocated
based on the construct path.
Roadmap

AutoScaling (combine EC2 and Kubernetes scaling)