is it possible to create Kubernetes pods, services, replica controllers etc on AWS cloudfromation? - kubernetes

Question

does AWS cloudformation supports creation of Kubernetes pods, services, replica controllers etc or setting up the EKS clusters and worker nodes and using Kubectl to create the resources are the only way?

Answer 1

Not out of the box, but you can if you use a custom resource type backed by a lambda function in CloudFormation.
The AWS EKS quickstart has an example:
AWSTemplateFormatVersion: "2010-09-09"
Description: "deploy an example workload into an existing kubernetes cluster (qs-1p817r5f9)"
Parameters:
KubeConfigPath:
Type: String
KubeConfigKmsContext:
Type: String
Default: "EKSQuickStart"
KubeClusterName:
Type: String
NodeInstanceProfile:
Type: String
QSS3BucketName:
AllowedPattern: ^[0-9a-zA-Z]+([0-9a-zA-Z-]*[0-9a-zA-Z])*$
ConstraintDescription: Quick Start bucket name can include numbers, lowercase
letters, uppercase letters, and hyphens (-). It cannot start or end with a hyphen
(-).
Default: aws-quickstart
Description: S3 bucket name for the Quick Start assets. This string can include
numbers, lowercase letters, uppercase letters, and hyphens (-). It cannot start
or end with a hyphen (-).
Type: String
QSS3KeyPrefix:
AllowedPattern: ^[0-9a-zA-Z-/.]*$
ConstraintDescription: Quick Start key prefix can include numbers, lowercase letters,
uppercase letters, hyphens (-), dots(.) and forward slash (/).
Default: quickstart-amazon-eks/
Description: S3 key prefix for the Quick Start assets. Quick Start key prefix
can include numbers, lowercase letters, uppercase letters, hyphens (-), dots(.) and
forward slash (/).
Type: String
QSS3BucketRegion:
Default: 'us-east-1'
Description: The AWS Region where the Quick Start S3 bucket (QSS3BucketName) is
hosted. When using your own bucket, you must specify this value.
Type: String
LambdaZipsBucketName:
Description: 'OPTIONAL: Bucket Name where the lambda zip files should be placed,
if left blank a bucket will be created.'
Type: String
Default: ''
K8sSubnetIds:
Type: List<AWS::EC2::Subnet::Id>
VPCID:
Type: AWS::EC2::VPC::Id
ControlPlaneSecurityGroup:
Type: AWS::EC2::SecurityGroup::Id
Conditions:
CreateLambdaZipsBucket: !Equals
- !Ref 'LambdaZipsBucketName'
- ''
UsingDefaultBucket: !Equals [!Ref QSS3BucketName, 'aws-quickstart']
Resources:
WorkloadStack:
Type: AWS::CloudFormation::Stack
Properties:
TemplateURL: !Sub
- 'https://${S3Bucket}.s3.${S3Region}.${AWS::URLSuffix}/${QSS3KeyPrefix}templates/example-workload.template.yaml'
- S3Region: !If [UsingDefaultBucket, !Ref 'AWS::Region', !Ref QSS3BucketRegion]
S3Bucket: !If [UsingDefaultBucket, !Sub '${QSS3BucketName}-${AWS::Region}', !Ref QSS3BucketName]
Parameters:
KubeManifestLambdaArn: !GetAtt KubeManifestLambda.Arn
HelmLambdaArn: !GetAtt HelmLambda.Arn
KubeConfigPath: !Ref KubeConfigPath
KubeConfigKmsContext: !Ref KubeConfigKmsContext
KubeClusterName: !Ref KubeClusterName
NodeInstanceProfile: !Ref NodeInstanceProfile
CopyZips:
Type: Custom::CopyZips
Properties:
ServiceToken: !GetAtt 'CopyZipsFunction.Arn'
DestBucket: !Ref LambdaZipsBucketName
SourceBucket: !If [UsingDefaultBucket, !Sub '${QSS3BucketName}-${AWS::Region}', !Ref QSS3BucketName]
Prefix: !Ref 'QSS3KeyPrefix'
Objects:
- functions/packages/Helm/lambda.zip
- functions/packages/DeleteBucketContents/lambda.zip
- functions/packages/KubeManifest/lambda.zip
- functions/packages/LambdaEniCleanup/lambda.zip
VPCLambdaCleanup:
Type: Custom::LambdaCleanup
Properties:
ServiceToken: !GetAtt VPCLambdaCleanupLambdaFunction.Arn
Region: !Ref "AWS::Region"
LambdaFunctionNames:
- !Ref KubeManifestLambda
VPCLambdaCleanupLambdaFunction:
DependsOn: CopyZips
Type: "AWS::Lambda::Function"
Properties:
Handler: lambda_function.lambda_handler
MemorySize: 128
Role: !GetAtt LambdaCleanUpFunctionRole.Arn
Runtime: python3.7
Timeout: 900
Code:
S3Bucket: !Ref LambdaZipsBucketName
S3Key: !Sub '${QSS3KeyPrefix}functions/packages/LambdaEniCleanup/lambda.zip'
HelmLambda:
DependsOn: CopyZips
Type: AWS::Lambda::Function
Properties:
Handler: lambda_function.lambda_handler
MemorySize: 128
Role: !GetAtt ManifestRole.Arn
Runtime: python3.6
Timeout: 900
Code:
S3Bucket: !Ref LambdaZipsBucketName
S3Key: !Sub '${QSS3KeyPrefix}functions/packages/Helm/lambda.zip'
VpcConfig:
SecurityGroupIds: [ !Ref EKSLambdaSecurityGroup ]
SubnetIds: !Ref K8sSubnetIds
KubeManifestLambda:
DependsOn: CopyZips
Type: AWS::Lambda::Function
Properties:
Handler: lambda_function.lambda_handler
MemorySize: 128
Role: !GetAtt ManifestRole.Arn
Runtime: python3.6
Timeout: 900
Code:
S3Bucket: !Ref LambdaZipsBucketName
S3Key: !Sub '${QSS3KeyPrefix}functions/packages/KubeManifest/lambda.zip'
VpcConfig:
SecurityGroupIds: [ !Ref EKSLambdaSecurityGroup ]
SubnetIds: !Ref K8sSubnetIds
DeleteBucketContentsLambda:
DependsOn: CopyZips
Type: AWS::Lambda::Function
Properties:
Handler: lambda_function.lambda_handler
MemorySize: 128
Role: !GetAtt DeleteBucketContentsRole.Arn
Runtime: python3.7
Timeout: 900
Code:
S3Bucket: !Ref LambdaZipsBucketName
S3Key: !Sub '${QSS3KeyPrefix}functions/packages/DeleteBucketContents/lambda.zip'
CopyZipsFunction:
Type: AWS::Lambda::Function
Properties:
Description: Copies objects from a source S3 bucket to a destination
Handler: index.handler
Runtime: python3.7
Role: !GetAtt CopyZipsRole.Arn
Timeout: 900
Code:
ZipFile: |
import json
import logging
import threading
import boto3
import cfnresponse
def copy_objects(source_bucket, dest_bucket, prefix, objects):
s3 = boto3.client('s3')
for o in objects:
key = prefix + o
copy_source = {
'Bucket': source_bucket,
'Key': key
}
print('copy_source: %s' % copy_source)
print('dest_bucket = %s'%dest_bucket)
print('key = %s' %key)
s3.copy_object(CopySource=copy_source, Bucket=dest_bucket,
Key=key)
def delete_objects(bucket, prefix, objects):
s3 = boto3.client('s3')
objects = {'Objects': [{'Key': prefix + o} for o in objects]}
s3.delete_objects(Bucket=bucket, Delete=objects)
def timeout(event, context):
logging.error('Execution is about to time out, sending failure response to CloudFormation')
cfnresponse.send(event, context, cfnresponse.FAILED, {}, physical_resource_id)
def handler(event, context):
physical_resource_id = None
if "PhysicalResourceId" in event.keys():
physical_resource_id = event["PhysicalResourceId"]
# make sure we send a failure to CloudFormation if the function is going to timeout
timer = threading.Timer((context.get_remaining_time_in_millis()
/ 1000.00) - 0.5, timeout, args=[event, context])
timer.start()
print('Received event: %s' % json.dumps(event))
status = cfnresponse.SUCCESS
try:
source_bucket = event['ResourceProperties']['SourceBucket']
dest_bucket = event['ResourceProperties']['DestBucket']
prefix = event['ResourceProperties']['Prefix']
objects = event['ResourceProperties']['Objects']
if event['RequestType'] == 'Delete':
delete_objects(dest_bucket, prefix, objects)
else:
copy_objects(source_bucket, dest_bucket, prefix, objects)
except Exception as e:
logging.error('Exception: %s' % e, exc_info=True)
status = cfnresponse.FAILED
finally:
timer.cancel()
cfnresponse.send(event, context, status, {}, physical_resource_id)
LambdaZipsBucket:
Type: AWS::S3::Bucket
Condition: CreateLambdaZipsBucket
LambdaCleanUpFunctionRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Statement:
- Action: ['sts:AssumeRole']
Effect: Allow
Principal:
Service: [lambda.amazonaws.com]
Version: '2012-10-17'
Path: /
Policies:
- PolicyName: LambdaRole
PolicyDocument:
Version: '2012-10-17'
Statement:
- Action:
- 'logs:CreateLogGroup'
- 'logs:CreateLogStream'
- 'logs:PutLogEvents'
Effect: Allow
Resource: !Sub "arn:${AWS::Partition}:logs:*:*:*"
- Action:
- 'ec2:*'
Effect: Allow
Resource: "*"
DeleteBucketContentsRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal:
Service: lambda.amazonaws.com
Action: sts:AssumeRole
ManagedPolicyArns:
- !Sub 'arn:${AWS::Partition}:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
Policies:
- PolicyName: deletebucketcontents
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action: s3:*
Resource:
- !Sub 'arn:${AWS::Partition}:s3:::${LambdaZipsBucketName}/*'
- !Sub 'arn:${AWS::Partition}:s3:::${LambdaZipsBucketName}'
CopyZipsRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal:
Service: lambda.amazonaws.com
Action: sts:AssumeRole
ManagedPolicyArns:
- !Su 'arn:${AWS::Partition}:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
Policies:
- PolicyName: lambda-copier
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action: s3:GetObject
Resource: !Sub
- 'arn:${AWS::Partition}:s3:::${S3Bucket}/${QSS3KeyPrefix}*'
- S3Bucket: !If [UsingDefaultBucket, !Sub '${QSS3BucketName}-${AWS::Region}', !Ref QSS3BucketName]
- Effect: Allow
Action:
- s3:PutObject
- s3:DeleteObject
Resource: !Sub 'arn:${AWS::Partition}:s3:::${LambdaZipsBucketName}/${QSS3KeyPrefix}*'
ManifestRole:
Type: "AWS::IAM::Role"
Properties:
AssumeRolePolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Principal:
Service: lambda.amazonaws.com
Action: sts:AssumeRole
Policies:
- PolicyName: eksStackPolicy
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action: s3:GetObject
Resource: !Sub
- "arn:${AWS::Partition}:s3:::${BucketName}/*"
- S3Bucket: !If [UsingDefaultBucket, !Sub '${QSS3BucketName}-${AWS::Region}', !Ref QSS3BucketName]
- Effect: Allow
Action:
- logs:CreateLogGroup
- logs:CreateLogStream
- logs:PutLogEvents
- ec2:CreateNetworkInterface
- ec2:DescribeNetworkInterfaces
- ec2:DeleteNetworkInterface
Resource:
- "*"
- Action: "kms:decrypt"
Effect: Allow
Resource: "*"
- Action: "s3:GetObject"
Effect: Allow
Resource: "*"
EKSLambdaSecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: Security group for lambda to communicate with cluster API
VpcId: !Ref VPCID
ClusterControlPlaneSecurityGroupIngress:
Type: AWS::EC2::SecurityGroupIngress
Properties:
Description: Allow lambda to communicate with the cluster API Server
GroupId: !Ref ControlPlaneSecurityGroup
SourceSecurityGroupId: !Ref EKSLambdaSecurityGroup
IpProtocol: tcp
ToPort: 443
FromPort: 443
It works by creating a lambda function customer resource KubeManifestLambda and HelmLambda that has kubectl and helm installed respectively, both configured with a role that allows them to access the EKS k8s cluster.
Then these custom resources can be used to deploy k8s manifests and helm charts with custom values, like in this example.
KubeManifestExample:
Type: "Custom::KubeManifest"
Version: '1.0'
Properties:
# The lambda function that executes the manifest against the cluster. This is created in one of the parent stacks
ServiceToken: !Ref KubeManifestLambdaArn
# S3 path to the encrypted config file eg. s3://my-bucket/kube/config.encrypted
KubeConfigPath: !Ref KubeConfigPath
# context for KMS to use when decrypting the file
KubeConfigKmsContext: !Ref KubeConfigKmsContext
# Kubernetes manifest
Manifest:
apiVersion: v1
kind: ConfigMap
metadata:
# If name is not specified it will be automatically generated,
# and can be retrieved with !GetAtt LogicalID.name
#
# name: test
#
# if namespace is not specified, "default" namespace will be used
namespace: kube-system
data:
# examples of consuming outputs of the HelmExample resource below's output. Creates an implicit dependency, so
# this resource will only launch once the HelmExample resource has completed successfully
ServiceCatalogReleaseName: !Ref HelmExample
ServiceCatalogKubernetesServiceName: !GetAtt HelmExample.Service0
This even lets you reference other Cloud formation resources such as RDS instances that are created as part of a workload.

Answer 2

You can use CloudFormation to create EKS cluster and worker nodes but you have to use kubectl for any operation on cluster like creating service, pods, deployments etc.....you can’t use CloudFormation for that

Answer 3

If you use CDK, you can use cluster.add_helm_chart() or HelmChart class. It will create a lambda behind the scenes.
Or you can create a lambda directly with https://docs.aws.amazon.com/cdk/api/v2/python/aws_cdk.lambda_layer_kubectl/README.html