Kubernetes | Luis Cacho

Trigger a scheduled job manually on Kubernetes

Thu, 22 Jun 2023 00:00:00 +0000

# Mockup command
kubectl create job --from=cronjob/<cronjob-name> <job-name> -n <namespace-name>

References:

¹How can I trigger a Kubernetes Scheduled Job manually?

https://stackoverflow.com/questions/40401795/how-can-i-trigger-a-kubernetes-scheduled-job-manually ↩︎

Delete OpenShift Operator

Mon, 15 Aug 2022 00:00:00 +0000

# Mockup commands

oc get subscription <operator> -n openshift-operators -o yaml | grep
currentCSV

oc delete subscription <operator> -n openshift-operators

oc delete clusterserviceversion <currentCSV> -n openshift-operators

# Example commands

oc get subscription jaeger -n openshift-operators -o yaml | grep currentCSV

oc delete subscription jaeger -n openshift-operators

oc delete clusterserviceversion jaeger-operator.v1.8.2 -n openshift-operators

Delete OpenShift Project

Mon, 15 Aug 2022 00:00:00 +0000

Issue, can’t delete a namespace/project and is stuck in a “Terminating” status

oc delete project fishbone

oc get projects fishbone
NAME DISPLAY NAME STATUS
fishbone Fishbone Terminating

Solution

Define the namespace/project to delete

export NAMESPACE=fishbone

Cleanup the finalizers section from the namespace definition and define a json file with that

oc get namespace $NAMESPACE -o=json | jq '.spec = {"finalizers":[]}' > $NAMESPACE.json
{
 "apiVersion": "v1",
 "kind": "Namespace",
 "metadata": {
 "annotations":
 "openshift.io/description": "",
 "openshift.io/display-name": "Fishbone",
 "openshift.io/requester": "system:admin",
 "openshift.io/sa.scc.mcs": "s0:c24,c14",
 "openshift.io/sa.scc.supplemental-groups": "1000580000/10000",
 "openshift.io/sa.scc.uid-range": "1000580000/10000"
 },
 "creationTimestamp": "2021-02-20T03:29:59Z",
 "deletionTimestamp": "2021-02-20T03:31:35Z",
 "name": "fishbone",
 "resourceVersion": "270664",
 "selfLink": "/api/v1/namespaces/fishbone",
 "uid": "885c4440-6f05-4e72-a103-28e61705406f"
 },
 "spec": {
 "finalizers": [
 "kubernetes"
 ]
 },
 "status": {
 "conditions": [
 .
 .
 .
 ],
 "phase": "Terminating"
}

Apply the json file from the previous step to delete the finalizers and therefore the deletion of the namespace/project

curl -k -H "authorization: Bearer $(oc whoami --show-token)" -H "Content-Type: application/json" -X PUT --data-binary @$NAMESPACE.json $(oc whoami --show-server)/api/v1/namespaces/$NAMESPACE/finalize

Verify that the namspace/project has been deleted

oc get projects $NAMESPACE
Error from server (NotFound): namespaces "fishbone" not found

References:

Kubernetes Advanced Topics¹
Kubernetes Namespace Stuck²
Red Hat article[^3]

How to Retrieve secrets values

Mon, 15 Aug 2022 00:00:00 +0000

oc get secret my-secret -n my-project --template={{.data.my-secret-key}} | base64 -d

oc get secret my-secret -n my-project -o go-template --template="{{.data.my-secret-key|base64decode}}"

oc extract secrets/my-secret -n my-project

oc get secret my-secret -n my-project -o jsonpath="{.data['tls\.key']}" | base64 -d

How to list the taints on kubernetes nodes

Sun, 14 Aug 2022 00:00:00 +0000

oc get nodes -o json | jq '.items[].spec.taints'
oc get nodes -o json | jq '.items[] | {node_name:.metadata.name,taints:.spec.taints[]?}

oc get nodes -o=custom-columns=NAME:.metadata.name,TAINTS:.spec.taints

get nodes -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.taints}{"\n"}{end}'

References:

¹ StackOverflow

]: https://stackoverflow.com/questions/43379415/how-can-i-list-the-taints-on-kubernetes-nodes ↩︎

Command to perform a curl to a PodIP

Thu, 05 Aug 2021 00:00:00 +0000

curl $(oc get pod <pod-name> --template '{{ .status.podIP}}):8080

Kubernetes debug commands

Sun, 01 Aug 2021 00:00:00 +0000

Kubernetes error messages

kubectl get events -n kube-system

Kubernetes pods logs

stern prox -n kube-system

Debug with busybox

kubectl run --generator=run-pod/v1 -i --tty busybox --image=busybox --restart=Never -- sh

Wait for pod to be ready

Thu, 15 Jul 2021 00:00:00 +0000

export POD_NAME=hello-d8d8d7455-j9nzw
while [[ $(oc get pods $POD_NAME -o 'jsonpath={..status.conditions[?(@.type=="Ready")].status}') != "True" ]]; do echo "waiting for pod" && sleep 1; done

If you want to wait until all the pods with a common label you can do:

while [[ $(kubectl get pods -l app=hello -o 'jsonpath={..status.conditions[?(@.type=="Ready")].status}') != "True" ]]; do echo "waiting for pod" && sleep 1; done

Differences between Kubernetes and Openshift

Thu, 25 Mar 2021 09:10:47 -0500

Differences between Kubernetes and Openshift

Luis Cacho

Senior Container Infrastructure Consultant

@Red Hat

Kubernetes

Some assembly required

Kubernetes

Some assembly required

Kubernetes

Some assembly required

Openshift

Value Added

Openshift

Value Added

Openshift

Value Added

Openshift contains Kubernetes

Conclusion

Openshit IS a Kubernetes flavor

Thank You

Kubernetes Contributor

Sun, 27 Oct 2019 00:00:00 +0000

Contributing to the Kubernetes project in different special interest groups, mainly focused on migration and modernization, documentation, community, and user/contributor experience.

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Contributor on the Spanish translation content at kubernetes.io in sig-docs.

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konveyor

Ansible Galaxy Roles

Fri, 25 Oct 2019 00:00:00 +0000

CircleCI Role: Ansible role that installs CircleCI CLI on your server/workstation.
Sonobuoy Role: Ansible role that installs sonobuoy on your server/workstation.