#!/usr/bin/env python
"""Module with k8s nodegroup."""
from typing import Any, cast
from botocore.loaders import Loader
from troposphere import Base64, Equals, If, Not, NoValue, Output, Sub, autoscaling, ec2
from troposphere.policies import AutoScalingRollingUpdate, UpdatePolicy
from runway.cfngin.blueprints.base import Blueprint
from runway.cfngin.blueprints.variables.types import (
CFNNumber,
CFNString,
EC2ImageId,
EC2SecurityGroupId,
EC2SubnetIdList,
EC2VPCId,
)
[docs]
def get_valid_instance_types() -> Any:
"""Return list of instance types from ``botocore`` data.
``botocore>=2.32.1`` started including compressed data files in it's wheel artifact.
This broke the previous implementation of this function as it manually loaded the file.
Now, we use the loading mechanism built into ``botocore`` to load the data file
which automatically handles compressed vs uncompressed data.
"""
return cast("Any", Loader().load_service_model("ec2", "service-2"))["shapes"]["InstanceType"][
"enum"
]
[docs]
class NodeGroup(Blueprint):
"""CFNgin blueprint for creating k8s nodegroup."""
VARIABLES = {
"KeyName": {
"type": CFNString, # string to allow it to be unset
"description": "(Optional) EC2 Key Pair to allow SSH access to the instances",
"default": "",
},
"NodeImageId": {
"type": EC2ImageId,
"description": "AMI id for the node instances.",
},
"NodeInstanceType": {
"type": CFNString,
"description": "EC2 instance type for the node instances",
"default": "t2.medium",
"allowed_values": get_valid_instance_types(),
"constraint_description": "Must be a valid EC2 instance type",
},
"NodeInstanceProfile": {
"type": CFNString,
"description": "Instance profile for the nodes.",
},
"NodeAutoScalingGroupMinSize": {
"type": CFNNumber,
"description": "Minimum size of Node Group ASG.",
"default": 1,
},
"NodeAutoScalingGroupMaxSize": {
"type": CFNNumber,
"description": "Maximum size of Node Group ASG.",
"default": 3,
},
"NodeVolumeSize": {
"type": CFNNumber,
"description": "Node volume size",
"default": 20,
},
"ClusterName": {
"type": CFNString,
"description": "The cluster name provided when the "
"cluster was created. If it is "
"incorrect, nodes will not be able to "
"join the cluster.",
},
"BootstrapArguments": {
"type": CFNString,
"description": "Arguments to pass to the "
"bootstrap script. See "
"files/bootstrap.sh in "
"https://github.com/awslabs/amazon-eks-ami",
"default": "",
},
"NodeGroupName": {
"type": CFNString,
"description": "Unique identifier for the Node Group.",
},
"ClusterControlPlaneSecurityGroup": {
"type": EC2SecurityGroupId,
"description": "The security group of the cluster control plane.",
},
"VpcId": {"type": EC2VPCId, "description": "The VPC of the worker instances"},
"Subnets": {
"type": EC2SubnetIdList,
"description": "The subnets where workers can be created.",
},
"UseDesiredInstanceCount": {
"type": CFNString,
"description": "Should the initial bootstrap instance count be used?",
},
}
[docs]
def create_template(self) -> None:
"""Create template (main function called by CFNgin)."""
template = self.template
template.set_version("2010-09-09")
template.set_description(
"Kubernetes workers via EKS - V1.0.0 - compatible with amazon-eks-node-v23+"
)
# Metadata
template.set_metadata(
{
"AWS::CloudFormation::Interface": {
"ParameterGroups": [
{
"Label": {"default": "EKS Cluster"},
"Parameters": [
self.variables[i].name
for i in [
"ClusterName",
"ClusterControlPlaneSecurityGroup",
]
],
},
{
"Label": {"default": "Worker Node Configuration"},
"Parameters": [
self.variables[i].name
for i in [
"NodeGroupName",
"NodeAutoScalingGroupMinSize",
"NodeAutoScalingGroupMaxSize",
"UseDesiredInstanceCount",
"NodeInstanceType",
"NodeInstanceProfile",
"NodeImageId",
"NodeVolumeSize",
"KeyName",
"BootstrapArguments",
]
],
},
{
"Label": {"default": "Worker Network Configuration"},
"Parameters": [self.variables[i].name for i in ["VpcId", "Subnets"]],
},
]
}
}
)
# Conditions
template.add_condition(
"DesiredInstanceCountSpecified",
Equals(self.variables["UseDesiredInstanceCount"].ref, "true"),
)
template.add_condition("KeyNameSpecified", Not(Equals(self.variables["KeyName"].ref, "")))
# Resources
nodesecuritygroup = template.add_resource(
ec2.SecurityGroup(
"NodeSecurityGroup",
GroupDescription="Security group for all nodes in the cluster",
Tags=[
{
"Key": Sub("kubernetes.io/cluster/${ClusterName}"),
"Value": "owned",
},
],
VpcId=self.variables["VpcId"].ref,
)
)
template.add_output(
Output(
"NodeSecurityGroup",
Description="Security group for all nodes in the cluster",
Value=nodesecuritygroup.ref(),
)
)
template.add_resource(
ec2.SecurityGroupIngress(
"NodeSecurityGroupIngress",
Description="Allow node to communicate with each other",
GroupId=nodesecuritygroup.ref(),
SourceSecurityGroupId=nodesecuritygroup.ref(),
IpProtocol="-1",
FromPort=0,
ToPort=65535,
)
)
template.add_resource(
ec2.SecurityGroupIngress(
"NodeSecurityGroupFromControlPlaneIngress",
Description="Allow worker Kubelets and pods to receive "
"communication from the cluster control plane",
GroupId=nodesecuritygroup.ref(),
SourceSecurityGroupId=self.variables["ClusterControlPlaneSecurityGroup"].ref,
IpProtocol="tcp",
FromPort=1025,
ToPort=65535,
)
)
template.add_resource(
ec2.SecurityGroupEgress(
"ControlPlaneEgressToNodeSecurityGroup",
Description="Allow the cluster control plane to communicate "
"with worker Kubelet and pods",
GroupId=self.variables["ClusterControlPlaneSecurityGroup"].ref,
DestinationSecurityGroupId=nodesecuritygroup.ref(),
IpProtocol="tcp",
FromPort=1025,
ToPort=65535,
)
)
template.add_resource(
ec2.SecurityGroupIngress(
"NodeSecurityGroupFromControlPlaneOn443Ingress",
Description="Allow pods running extension API servers on port "
"443 to receive communication from cluster "
"control plane",
GroupId=nodesecuritygroup.ref(),
SourceSecurityGroupId=self.variables["ClusterControlPlaneSecurityGroup"].ref,
IpProtocol="tcp",
FromPort=443,
ToPort=443,
)
)
template.add_resource(
ec2.SecurityGroupEgress(
"ControlPlaneEgressToNodeSecurityGroupOn443",
Description="Allow the cluster control plane to communicate "
"with pods running extension API servers on port "
"443",
GroupId=self.variables["ClusterControlPlaneSecurityGroup"].ref,
DestinationSecurityGroupId=nodesecuritygroup.ref(),
IpProtocol="tcp",
FromPort=443,
ToPort=443,
)
)
template.add_resource(
ec2.SecurityGroupIngress(
"ClusterControlPlaneSecurityGroupIngress",
Description="Allow pods to communicate with the cluster API Server",
GroupId=self.variables["ClusterControlPlaneSecurityGroup"].ref,
SourceSecurityGroupId=nodesecuritygroup.ref(),
IpProtocol="tcp",
FromPort=443,
ToPort=443,
)
)
nodelaunchtemplate = template.add_resource(
ec2.LaunchTemplate(
"NodeLaunchTemplate",
LaunchTemplateData=ec2.LaunchTemplateData(
BlockDeviceMappings=[
ec2.LaunchTemplateBlockDeviceMapping(
DeviceName="/dev/xvda",
Ebs=ec2.EBSBlockDevice(
DeleteOnTermination=True,
VolumeSize=self.variables["NodeVolumeSize"].ref,
VolumeType="gp2",
),
),
],
IamInstanceProfile=ec2.IamInstanceProfile(
Arn=self.variables["NodeInstanceProfile"].ref
),
ImageId=self.variables["NodeImageId"].ref,
InstanceType=self.variables["NodeInstanceType"].ref,
KeyName=If("KeyNameSpecified", self.variables["KeyName"].ref, NoValue),
MetadataOptions=ec2.MetadataOptions(
HttpPutResponseHopLimit=2,
HttpEndpoint="enabled",
HttpTokens="optional",
),
SecurityGroupIds=[nodesecuritygroup.ref()],
UserData=Base64(
Sub(
"\n".join( # noqa: FLY002
[
"#!/bin/bash",
"set -o xtrace",
"/etc/eks/bootstrap.sh ${ClusterName} ${BootstrapArguments}",
"/opt/aws/bin/cfn-signal --exit-code $? \\",
" --stack ${AWS::StackName} \\",
" --resource NodeGroup \\",
" --region ${AWS::Region}",
"sudo yum install -y "
"https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/"
"latest/linux_amd64/amazon-ssm-agent.rpm",
"sudo systemctl enable amazon-ssm-agent",
"sudo systemctl start amazon-ssm-agent",
]
)
)
),
),
)
)
template.add_resource(
autoscaling.AutoScalingGroup(
"NodeGroup",
DesiredCapacity=If(
"DesiredInstanceCountSpecified",
self.variables["NodeAutoScalingGroupMaxSize"].ref,
NoValue,
),
LaunchTemplate=autoscaling.LaunchTemplateSpecification(
LaunchTemplateId=nodelaunchtemplate.ref(),
Version=nodelaunchtemplate.get_att("LatestVersionNumber"),
),
MinSize=self.variables["NodeAutoScalingGroupMinSize"].ref,
MaxSize=self.variables["NodeAutoScalingGroupMaxSize"].ref,
Tags=[
autoscaling.Tag("Name", Sub("${ClusterName}-${NodeGroupName}-Node"), True),
autoscaling.Tag(Sub("kubernetes.io/cluster/${ClusterName}"), "owned", True),
],
VPCZoneIdentifier=self.variables["Subnets"].ref,
UpdatePolicy=UpdatePolicy(
AutoScalingRollingUpdate=AutoScalingRollingUpdate(
MinInstancesInService="1", MaxBatchSize="1"
)
),
)
)
# Helper section to enable easy blueprint -> template generation
# (just run `python <thisfile>` to output the json)
if __name__ == "__main__":
from runway.context import CfnginContext
print( # noqa: T201
NodeGroup("test", CfnginContext(parameters={"namespace": "test"})).to_json()
)