As next step, we will add custom resources to ENIConfig custom resource definition (CRD). CRDs are extensions of Kubernetes API that stores collection of API objects of certain kind. In this case, we will store VPC Subnet and SecurityGroup configuration information in these CRDs so that Worker nodes can access them to configure VPC CNI plugin.
You should have ENIConfig CRD already installed with latest CNI version (1.3+). You can check if its installed by running this command.
kubectl get crd
You should see a response similar to this
If you don’t have ENIConfig installed, you can install it by using this commandkubectl apply -f https://raw.githubusercontent.com/aws/amazon-vpc-cni-k8s/release-1.7/config/v1.7/aws-k8s-cni.yaml
Create custom resources for each subnet by replacing Subnet and SecurityGroup IDs. Since we created three secondary subnets, we need create three custom resources.
Here is the template for custom resource. Notice the values for Subnet ID and SecurityGroup ID needs to be replaced with appropriate values
apiVersion: crd.k8s.amazonaws.com/v1alpha1
kind: ENIConfig
metadata:
name: group1-pod-netconfig
spec:
subnet: $SUBNETID1
securityGroups:
- $SECURITYGROUPID1
- $SECURITYGROUPID2
Check the AZs and Subnet IDs for these subnets. Make note of AZ info as you will need this when you apply annotation to Worker nodes using custom network config
aws ec2 describe-subnets --filters "Name=cidr-block,Values=100.64.*" --query 'Subnets[*].[CidrBlock,SubnetId,AvailabilityZone]' --output table
INSTANCE_IDS=(`aws ec2 describe-instances --query 'Reservations[*].Instances[*].InstanceId' --filters "Name=tag-key,Values=eks:cluster-name" "Name=tag-value,Values=eksworkshop*" --output text`)
for i in "${INSTANCE_IDS[@]}"
do
echo "SecurityGroup for EC2 instance $i ..."
aws ec2 describe-instances --instance-ids $i | jq -r '.Reservations[].Instances[].SecurityGroups[].GroupId'
done
Note: We are using same SecurityGroup for pods as your Worker Nodes but you can change these and use custom SecurityGroups for your Pod Networking
apiVersion: crd.k8s.amazonaws.com/v1alpha1
kind: ENIConfig
metadata:
name: group1-pod-netconfig
spec:
subnet: subnet-04f960ffc8be6865c
securityGroups:
- sg-070d03008bda531ad
- sg-06e5cab8e5d6f16ef
Create custom resource group2-pod-netconfig.yaml for second subnet (100.64.32.0/19). Replace the SubnetId and SecuritGroupIds as above.
Similarly, create custom resource group3-pod-netconfig.yaml for third subnet (100.64.64.0/19). Replace the SubnetId and SecuritGroupIds as above.
Check the instance details using this command as you will need AZ info when you apply annotation to Worker nodes using custom network config
aws ec2 describe-instances --filters "Name=tag-key,Values=eks:cluster-name" "Name=tag-value,Values=eksworkshop*" --query 'Reservations[*].Instances[*].[PrivateDnsName,Tags[?Key==`eks:nodegroup-name`].Value|[0],Placement.AvailabilityZone,PrivateIpAddress,PublicIpAddress]' --output table
Apply the CRDs
kubectl apply -f group1-pod-netconfig.yaml
kubectl apply -f group2-pod-netconfig.yaml
kubectl apply -f group3-pod-netconfig.yaml
As last step, we will annotate nodes with custom network configs.
Be sure to annotate the instance with config that matches correct AZ. For ex, in my environment instance ip-192-168-33-135.us-east-2.compute.internal is in us-east-2b. So, I will apply group1-pod-netconfig.yaml to this instance. Similarly, I will apply group2-pod-netconfig.yaml to ip-192-168-71-211.us-east-2.compute.internal and group3-pod-netconfig.yaml to ip-192-168-9-228.us-east-2.compute.internal
kubectl annotate node <nodename>.<region>.compute.internal k8s.amazonaws.com/eniConfig=group1-pod-netconfig
As an example, here is what I would run in my environment
You should now see secondary IP address from extended CIDR assigned to annotated nodes.Optionally, you specify which node label will be used to match the ENIConfig name. Consider the
following example: you have one ENIConfig per availability zone, named after the AZ
(us-east-2a, us-east-2b, us-east-2c). You can then use a label already applied to your nodes,
such as topology.kubernetes.io/zone where the value of the label matches the ENIConfig name.
Kubernetes will now apply the corresponding ENIConfig matching the nodes AZ.