• kubebuilder:printcolumn - Adding back the AGE column

    1 min read

    Operator-SDK kubebuilder printcolumn age

    If we use //+kubebuilder:printcolumn to add fields to print with kubectl get we'll notice that the AGE colum goes away with it. We can use an additional //+kubebuilder:printcolumn to add the AGE column back.

    29/08/2023

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  • Pushing metric to prometheus with Pushgateway

    2 min read

    kubernetes prometheus Pushgateway

    Prometheus Pushgateway is a component of the Prometheus monitoring system that allows for the collection of time-series data that cannot be scraped: It allows you to push metrics instead of having to wait for prometheus to scrape them

    15/08/2023

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  • Operator-SDK: Create a group of objects that can be queried together

    2 min read

    Operator-SDK CustomResourceDefinition categories groups

    When you have several kubernetes objects (CRDs) that work together it can be useful to be able to query them all together to get a better idea of what's deployed without having to query all the individial resources. With operator-SDK we just need to annotate the objects.

    01/08/2023

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  • Kubernetes: Search the specific rule granting a given permission

    2 min read

    kubernetes role clusterrole rule search kubectl

    Sometimes might be difficult to tell how some subject (User, ServiceAccount, ...) is able to perform a certain task: What's the Role or ClusterRole granting some permission?

    For this we can use the searchrule plugin.

    25/07/2023

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  • Monitoring APIRequestCount in OpenShift

    2 min read

    OpenShift APIRequestCount monitoring API usage

    Openshift provides an object that tracks the number of requests made to the Kubernetes API server. It provides insights into the load on the cluster, the performance of applications, and helps in capacity planning. By monitoring APIRequestCount, you can identify potential bottlenecks, detect unusual spikes in traffic, and optimize resource allocation.

    $ kubectl get apirequestcounts
    NAME                                                                           REMOVEDINRELEASE   REQUESTSINCURRENTHOUR   REQUESTSINLAST24H
    alertmanagerconfigs.v1alpha1.monitoring.coreos.com                                                6                       1706
    alertmanagers.v1.monitoring.coreos.com                                                            20                      2891
    apiservices.v1.apiregistration.k8s.io                                                             994                     99521
    (...)
    

    11/07/2023

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Kubernetes:
container orchestration
kubernetes
tags related to this category
operator-sdk golang Pushgateway RBAC Rule troubleshooting APIRequestCount Pod affinity topologySpreadConstraints Route ExternalSecret Secret kubectl jsonpath ServiceAccount Ingress k3s letsencrypt tcpdump ssh CRD additionalPrinterColumns Velero query PV Operator Role ClusterRole web-console operator oc-mirror Secrets Manager tekton context Policy enforcement Rules Project ConfigMap Environment ROSA IngressRoute redirect RDS psql kind API server S3 patch file apply selector minikube arm64 colima EKS-connector SecurityContextConstraint SecretStore scripting CRC credentials Deployment valueFrom setup helm StorageClass tagging EBS externalDNS ALB HPA plugin convert API version example custom command shipwright ECR imagePullSecrets ENI subnet krew blame cloud provider etcd availability zones CoreDNS backend state Kaniko podAntiAffinity Composite images GKE activeDeadlineSeconds Job lifetime bestby IRSA label annotation PersistentVolume StatefulSet Volume fsGroup vpa cluster autoscaler Karpenter provider kubernetes_manifest fsGroupChangePolicy container escape spot instances termination handler persistentVolumeReclaimPolicy fieldPath upgrade privileged network NetworkPolicy bash ps longhorn ASCP QoD raspberry pi drain evict uncordon kubeconfig config view logs admission controller hook postStart preStop deprecations gp3 get-all taints securityGroup probe readinessProbe livenessProbe tolerations explain MutatingWebhook startupProbe RollingUpdate Recreate PDB emptyDir socat netstat ss autoscale Kubeconfig initContainers DNS tree DaemonSet stern tail LimitRange resource limits restartPolicy system-upgrade-controller rolling update history undo Volumes awsElasticBlockStore change-cause set image imperative port-forward hostAliases imagePullPolicy metrics-server Service overlay agent nodes declarative ELB HTTPS alpine package nodeSelector scheduler kubie api-versions events multiple containers SecretKeyRef ReplicaSet NodePort Pod restart rollout deployment nginx-contoller ValidatingWebhookConfiguration error recovery httpHeaders security uid securityContext exec interactive LoadBalancer IAM scale replicas nodeName externalName namespace Cronjob multinode template yaml unused-volumes diff