Enabling Group Metrics Collection for NodeGroup of AWS EKS and Capacity Alarm.

script-for-enabling-nodegroup-metrics.sh

# Get's the FIRST Cluster on list-clusters. Assuming you only have 1 EKS 
EKS_CLUSTER_NAME=$(aws eks list-clusters --region=eu-central-1 | jq -r .clusters[0])
echo $EKS_CLUSTER_NAME
# First NodeGroup from the list.
NG=$(aws eks list-nodegroups --cluster-name $EKS_CLUSTER_NAME | jq -r '.nodegroups[0]')
echo $NG
# First Autoscaling Group Name
ASG_NAME=$(aws eks describe-nodegroup --cluster-name $EKS_CLUSTER_NAME --nodegroup-name $NG | jq -r '.nodegroup.resources.autoScalingGroups[0].name')

# Enable Autoscaling Group Metrics
aws autoscaling enable-metrics-collection --auto-scaling-group-name $ASG_NAME --granularity "1Minute"


# --------- Extra ---------- 
# Get SNS Topic ARN for Alarms.
SNS_ARN=$(aws sns list-topics | jq -r '.Topics[0].TopicArn')
# EKS Autoscaling Capacity Alarm
EKS_ASG_MAX_SIZE=$(aws cloudformation describe-stacks | jq -r --arg EKS_CLUSTER_NAME "$EKS_CLUSTER_NAME" '.Stacks[] | select( .StackName == $EKS_CLUSTER_NAME+"-eks-nodegroup")' | jq -r '.Parameters[] | select(.ParameterKey == "EksAsgMaxSize") | .ParameterValue')
aws cloudwatch put-metric-alarm --alarm-name "${EKS_CLUSTER_NAME}-EKS NodeGroup EksAsgCapacityAlarm" --evaluation-periods 1 --comparison-operator GreaterThanOrEqualToThreshold --metric-name GroupTotalInstances --period 600 --namespace AWS/AutoScaling --statistic Maximum --threshold $EKS_ASG_MAX_SIZE --dimensions Name=AutoScalingGroupName,Value=$ASG_NAME --ok-actions $SNS_ARN --alarm-actions $SNS_ARN