Elastic Kubernetes Services (EKS)

eksctl

• eksctl is a cli tool developed by Weaveworks & is easiest way to deploy all components needed to run EKS
• Refer Here for official site of eksctl
• eksctl defaults to creating a cluster with following default paramters
  • An autogenerated cluster name
  • Two m5.large worker nodes
  • Use of official AWS EKS AMI
  • us-west-2 defaul region
  • dedicated vpc
• Network information
  • dedicated vpc 192.168.0.0/16 with three private, three public subnets
  • NAT Gateway & Internet gateway to enable acess needed for container images & communication to AWS S3 and ECR API
  • Two security groups are setup for eks cluster
    • Ingress internode group SG: Allows nodes to communicate with each other on all ports
    • Control Plane security group: Allows communication between the control plane and worker node groups
• One node group containing two m5.large nodes is default, but how many pods can that node run? AWS has a formula based on the node type and number of interfaces and Ip Adddresses it supports.
  ((Number of network interfaces for the instance type) * (Number of Ip Addresses per network interface -1)) + 2
• m5 large can support a maximum of 29 pods

AWS VPC CNI

• This is an open source implementation of CNI built for AWS
• This includes native AWS Services like VPC Flow logs, VPC routing policies, security groups for network traffic isolation
• Refer Here for VPC CNI
• Two components of VPC CNI
  • CNI Plugin: responsible for host and pod’s network stack
  • ipamd: IPAM dameon responsible for maintaining warm pool of available IP addresses and assign and IP to pod
    
• refer class room video for demonstration of the above