In your pod or buildconfig yaml you can specify which nodes the pod should run on, generally by specifying one or more of the labels assigned to the appropriate nodes. For instance {"zone":"east"}.
Sometimes you want to be more specific and have a pod run on a very specific host. To find out which labels are available for the nodes, run the following command:
$ oc get nodes --show-labels
Example output:
NAME STATUS AGE VERSION LABELS infra-0 Ready 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2s_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=0,kubernetes.io/hostname=infra-0,logging-infra-fluentd=true,logging=true,region=infra,type=infra,zone=default infra-1 Ready 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2s_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=1,kubernetes.io/hostname=infra-1,logging-infra-fluentd=true,logging=true,region=infra,type=infra,zone=default master-0 Ready,SchedulingDisabled 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=0,kubernetes.io/hostname=master-0,logging-infra-fluentd=true,logging=true,openshift-infra=apiserver,type=master,zone=default master-1 Ready,SchedulingDisabled 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=0,kubernetes.io/hostname=master-1,logging-infra-fluentd=true,logging=true,type=master,zone=default master-2 Ready,SchedulingDisabled 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=1,kubernetes.io/hostname=master-2,logging-infra-fluentd=true,logging=true,type=master,zone=default node-0 Ready 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2s_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=0,kubernetes.io/hostname=node-0,logging-infra-fluentd=true,logging=true,type=app,zone=default node-1 Ready 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2s_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=1,kubernetes.io/hostname=node-1,logging-infra-fluentd=true,logging=true,type=app,zone=default node-2 Ready 48d v1.7.6+a08f5eeb62 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=Standard_E2s_v3,beta.kubernetes.io/os=linux,failure-domain.beta.kubernetes.io/region=canadaeast,failure-domain.beta.kubernetes.io/zone=0,kubernetes.io/hostname=node-2,logging-infra-fluentd=true,logging=true,type=app,zone=default
From this you will see that each node has a kubernetes.io/hostname label. You can use this in your annotations for the pod of buildconfig.
apiVersion: apps.openshift.io/v1
kind: DeploymentConfig
spec:
template:
spec:
nodeSelector:
kubernetes.io/hostname: node-0