Earlier in the workshop, in the Add EKS managed Spot workers chapter, we created node groups that run a diversified set of Spot Instances to run our applications. Let’s create a new nodegroup configuration section within the main.tf Terraform template. Remember to continue using your Cloud9 workspace to run all commands.
The Jenkins default resource requirements (Request and Limit CPU/Memory) are 512m (~0.5 vCPU) and 512Mi (~0.5 GB RAM), and since we are not going to perform any large build jobs in this workshop, we can stick to the defaults and also choose relatively small instance types that can accommodate the Jenkins agent pods.
Within the main.tf template file, in the managed_node_groups section, paste the following code snippet to create the Jenkins Spot node group:
jenkins_agents_mng_spot_2vcpu_8gb = {
node_group_name = "jenkins-agents-mng-spot-2vcpu-8gb"
capacity_type = "SPOT"
instance_types = ["m4.large", "m5.large", "m5a.large", "m5ad.large", "m5d.large", "t2.large", "t3.large", "t3a.large"]
max_size = 3
desired_size = 1
min_size = 0
subnet_type = "private"
subnet_ids = []
k8s_labels = {
intent = "jenkins-agents"
}
}
Run a terraform fmt to fix any identation problem (if any), then run:
terraform apply --auto-approve
The creation of the workers will take about 3 minutes.
There are a few things to note in the configuration that we just used to create these node groups.
Node groups configurations are set under the managed_node_groups section, this indicates that the node groups are managed by EKS.
The node group has large (2 vCPU and 8 GB) instance types with min_size 0, max_size 3 and desired_size 1.
The configuration capacity_type= “SPOT” indicates that the node group being created is a EKS managed node group with Spot capacity.
Notice that the we added a node label per node:
intent, to allow you to deploy jenkins agents on nodes that have been labeled with value jenkins-agents.