Configuring Dedicated Node Pools Flashcards
How do you add nodes in IPI
Modify the number of replicas specified in a Machine Set
Steps to add node in UPI
1) Update the compute node Ignition file with an updated TLS cert.
2) Install CoreOS from an ISO image or using a Preboot eXecution Environment (PXE) boot.
3) Add the new instance to the ingress load balancer.
4) Approve CSRs to allow the compute node to join the cluster.
List Ignition files generates by OPC install
bootstrap.ign
master.ign
worker.ign
Approve the certificate
1) oc get csr -A
2) oc adm certificate approve csr-lqcbd
Add compute nodes to a cluster, add the instance to external load balancer back-end pools
Add node with PXE install
1) Find pxelinux.cfg directory
2) In pxelinux.cfg, find NOOP file
3) In NOOP file, find location of the worker.ign file
4) Open worker.ign file and copy cert
5) Use the openssl to examine the x509 certificate
echo “LS0tL…g==” | base64 -d | openssl x509 -noout -text
6)
What does Machine Config Operator (MCO) do?
1) manages instance configuration changes and OS upgrades
2) uses MCP to track status as MCs are applied to nodes
how to set custom node configurations
by declaring MachineConfig and MachineConfigPool resources
MachineConfig (MC)
1) declare instance customizations using the Ignition config format.
2) labeled with a role such as worker or infra
MachineConfigPool (MCP)
use labels to match MCs to nodes
List Machine Configs for a specific role
oc get machineconfig –selector=machineconfiguration.openshift.io/role=worker
Default MCP
master and worker
MC CR
assign workloads to nodes that match the label
Get machinepool list
oc get machineconfigpool
