OpenShift Tips

Configuration

Get CRI-O settings

oc get containerruntimeconfig

OCP Master configuration

The master configuration is now stored in a configMap. During the installation process, a few configMaps are created, so in order to get the latest:

oc get cm -n openshift-kube-apiserver | grep config

Observe the latest id and then:

oc get cm -n openshift-kube-apiserver config-ID

To get the output in a human-readable form, use:

oc get cm -n openshift-kube-apiserver config-ID \
  -o jsonpath='{.data.config\.yaml}' | jq

For the OpenShift api configuration:

oc get cm -n openshift-apiserver config -o jsonpath='{.data.config\.yaml}' | jq

Observe the SDN configuration

oc get cm sdn-config -o yaml -n openshift-sdn

Or:

oc exec -n openshift-sdn $(oc get pods -n openshift-sdn -l app=sdn --no-headers=true -o custom-columns=:metadata.name|head -n1) cat /config/{kube-proxy-config,sdn-config}.yaml

Making Master Unscheduleable/Scheduleable

To configure master as unscheduleable (when UPI installation without setting this prior to the install):

oc patch --type=merge --patch='{"spec":{"mastersSchedulable": false}}' schedulers.config.openshift.io cluster

scheduler.config.openshift.io/cluster patched

Get Settings used in install config

oc get cm -n kube-system cluster-config-v1 -o yaml
Last updated on 9 Jun 2020
Published on 18 Jun 2019
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