Some Tips and Tricks for OCP (openshift)

You will find here some all day work tips for OpenShift Cluster and for the origin (okd) version, some of the commands also works for kubectl – Command line tool.

get nodeport🔗

oc get svc <your-service> -o jsonpath='{.spec.ports[?(@)].nodePort}'

get all released pv🔗

oc get pv \
--template='{{range .items}}{{if eq .status.phase "Released" }}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' \
--all-namespaces

The output.

pv020-volume
pv021-volume
pv022-volume
pv023-volume
pv025-volume
pv027-volume
pv034-volume
pv037-volume
pv038-volume
pv039-volume
pv042-volume
pv043-volume

Cleanup Released pvs🔗

⚠ | You need jq to execute the following snipplet

for i in $(oc get pv --template='{{range .items}}{{if eq .status.phase "Released" }}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' --all-namespaces ); 
do
  oc export pv $i -o json | jq 'del(.spec.claimRef)' > ${i}_no-claimRef.json
  oc delete pv $i && oc create -f ${i}_no-claimRef.json
  echo "rm -rf /mnt/$( echo $i|cut -d'-' -f1)/[a-z]*"
done

Running pods on Nodes🔗

This command shows which pod run on which node.

oc get po  --all-namespaces \
  -o go-template='{{range .items}}{{if eq .status.phase "Running" }}name: {{ printf "%19s" .metadata.name}}; Namespace: {{ printf "%15s" .metadata.namespace}}; Nodename: {{.spec.nodeName}}{{"\n"}}{{end}}{{end}}'

The output looks like this.

name:     router-51-f9gc4; Namespace:  dev-router; Nodename: app_n05
name:    router01-4-8z5gb; Namespace:  dev-router; Nodename: app_n01
name:    router02-4-mvd8l; Namespace:  dev-router; Nodename: app_n04
name:    router03-3-vnkn2; Namespace:  dev-router; Nodename: app_n04
name:    router04-2-gp4r7; Namespace:  dev-router; Nodename: app_n02
name:    router05-4-hmhnb; Namespace:  dev-router; Nodename: app_n02
name:    router12-4-vrcgc; Namespace:  dev-router; Nodename: app_n04
name:          ap-6-btgqf; Namespace:       dev01; Nodename: app_n05
name:          ap-1-4rz89; Namespace:       dev02; Nodename: app_n05
name:  ap-haproxy-1-q7tvq; Namespace:       dev03; Nodename: app_n02
name:          ap-1-blb8p; Namespace:       dev03; Nodename: app_n03

Print all labels🔗

with perl🔗

oc get node --show-labels --no-headers \ 
| perl -MData::Dumper -ane 'push(@{$hosts->{$F[0]}},split( "," , $F[5])) ; \ 
    END {foreach (reverse sort { $hosts->{$a} <=> $hosts->{$b} } keys %{$hosts}){ \
      printf("\n% 8s\n    %s\n",$_,join( " ; " , @{$hosts->{$_}}) );}}'

Output

nodei01
    beta.kubernetes.io/arch=amd64 ; beta.kubernetes.io/os=linux ; failure-domain.beta.kubernetes.io/zone=nova ; kubernetes.io/hostname=nodei01 ; logging-infra-fluentd=true ; node-role.kubernetes.io/compute=true ; region=primary ; role=infra ; router=yes ; zone=mgmt
nodei02
    beta.kubernetes.io/arch=amd64 ; beta.kubernetes.io/os=linux ; failure-domain.beta.kubernetes.io/zone=nova ; kubernetes.io/hostname=nodei02 ; logging-infra-fluentd=true ; node-role.kubernetes.io/compute=true ; region=primary ; role=infra ; router=yes ; zone=mgmt

without perl🔗

In case that the perl module Data::Dumper isn’t available here the solution with build-in go-template.

oc get node  --no-headers \
  -o go-template='{{range .items}}name:{{ .metadata.name }}{{"\n"}}{{range $key, $value := .metadata.labels}}  {{ $key }}{{"="}}{{ $value }}{{"\n"}}{{end}}{{"\n"}}{{end}}'|less11111

Collect and compress must-gather🔗

When you create an Red Hat Case is most of the time a must-gather recommended. The output of must-gather could be quite big why it’s recommended to compress the archive.

The commands below are for a bash shell.

# Save timestamp for followup commands
CURRENT_DATE=$(date +"%Y-%m-%d-%S")

# Save output from must gather

oc adm must-gather \
  --dest-dir=${CURRENT_DATE}_must-gather \
  >${CURRENT_DATE}_must-gather.txt 2>&1

# Compress the stdout and stderr output
xz -9 ${CURRENT_DATE}_must-gather.txt

# Compress the archive
XZ_DEFAULTS=-9 tar cfJ ${CURRENT_DATE}_must-gather.tar.xz ${CURRENT_DATE}_must-gather

oc snipplets🔗

get infos🔗

 oc -n default \
     get dc ipfailover \
     -o jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'

json patch🔗

oc -n default \
    patch dc/ipfailover \
    --type='json' \
    -p '[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"internal.registy/openshift3/ose-keepalived-ipfailover:v3.9.68"}]'

get secrets🔗

The ClientID in the snippets below is a key in the secret, you must replace it with the key in your secret.

with go-template🔗

From “secret” to plain text 😄.

$ oc -n ${NAMEPACE} get secrets ${SECRET} \
  -o go-template='{{.data.ClientID|base64decode}}{{"\n"}}'

with jsonpath🔗

$ oc -n ${NAMEPACE} get secrets \
  ${SECRET} \
  -o jsonpath='{.data.ClientID}' \
  | base64 -d

get spec🔗

$ oc -n ${NAMEPACE} get deployment \
  ${DEPLOYMENT} \
  -o jsonpath='{.spec}' \
  | jq