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Revisions

  1. pydevops revised this gist Nov 30, 2024. 1 changed file with 2 additions and 0 deletions.
    2 changes: 2 additions & 0 deletions kubectl.md
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    @@ -161,6 +161,8 @@ kubectl get --raw /apis/${group/version} | jq -r '.resources[].kind'
    kubectl get --raw /apis/apps/v1 | jq . -C | less -R
    API_SERVER_ENDPOINT="$(kubectl config view --raw -o json | jq -r '.clusters[0].cluster.server')
    ```

    ### list resources under a specific api version.
  2. pydevops revised this gist Nov 19, 2024. 1 changed file with 5 additions and 0 deletions.
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    @@ -265,4 +265,9 @@ kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes \
    | jq '[.items [] | {nodeName: .metadata.name, nodeCpu: .usage.cpu, nodeMemory: .usage.memory}]'
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/pods | jq . -C | less -R
    ```

    ## labels
    ```
    kubectl get nodes -L karpenter.sh/nodepool -L node.kubernetes.io/instance-type -L topology.kubernetes.io/zone -L karpenter.sh/capacity-type
    ```
  3. pydevops revised this gist Jul 16, 2024. 1 changed file with 9 additions and 0 deletions.
    9 changes: 9 additions & 0 deletions kubectl.md
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    @@ -108,6 +108,15 @@ kubectl run -it --rm debug --image=busybox -- sh
    ```
    * busybox https://busybox.net/downloads/BusyBox.html


    ## cert compare

    ```
    kubectl get validatingwebhookconfigurations.admissionregistration.k8s.io aws-load-balancer-webhook -ojsonpath={.webhooks[0].clientConfig.caBundle} | base64 -d | openssl x509 -noout -text
    kubectl get secret -n kube-system aws-load-balancer-tls -ojsonpath="{.data.ca\.crt}" |base64 -d |openssl x509 -noout -text
    ```


    ## context, namespace
    ```
    get current context: kubectl config view -o=jsonpath='{.current-context}'
  4. pydevops revised this gist Jul 12, 2024. 1 changed file with 13 additions and 1 deletion.
    14 changes: 13 additions & 1 deletion kubectl.md
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    @@ -86,10 +86,22 @@ Did this for cleaning up pods with not in Running state such as Terminated
    k get po --field-selector=status.phase!=Running -o custom-columns=":metadata.name" --no-headers | xargs kubectl delete po
    ```

    ## waitfor
    ## mysql and psql

    ```
    kubectl run -n default mysql-client-${USER} --image=mysql:5.7 -it --restart=Never -- /bin/bash
    kubectl run -n default psql-cli-${USER} --image=postgres -it --restart=Never -- bash
    ```


    ## wait for

    * https://vadosware.io/post/so-you-need-to-wait-for-some-kubernetes-resources/

    ```
    kubectl -n istio-system wait --for=jsonpath='{.data.ca\.crt}' secrets/cacerts
    ```

    ## debug
    ```
    kubectl run -it --rm debug --image=busybox -- sh
  5. pydevops revised this gist Jun 5, 2024. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion kubectl.md
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    ## reference
    ## references
    * https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands
    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)
    * https://medium.com/@bingolbalihasan/how-does-kubectl-work-writing-custom-kubectl-commands-da86e5d49c74
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    ## reference
    * https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands
    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)
    * https://medium.com/@bingolbalihasan/how-does-kubectl-work-writing-custom-kubectl-commands-da86e5d49c74

    ## cheatsheet & tips
    * https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
  7. pydevops revised this gist Aug 1, 2023. 1 changed file with 2 additions and 1 deletion.
    3 changes: 2 additions & 1 deletion kubectl.md
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    @@ -2,8 +2,9 @@
    * https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands
    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)

    ## cheatsheet
    ## cheatsheet & tips
    * https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
    * https://github.com/devoriales/kubectl-cheatsheet
    * https://learncloudnative.com/blog/2022-05-10-kubectl-tips
    * https://itnext.io/tips-tricks-for-cka-ckad-and-cks-exams-cc9dade1f76d
    * https://cloud.google.com/anthos/gke/docs/on-prem/reference/cheatsheet
  8. pydevops revised this gist Jun 14, 2023. 1 changed file with 5 additions and 2 deletions.
    7 changes: 5 additions & 2 deletions kubectl.md
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    @@ -181,10 +181,13 @@ kubectl rollout undo deployment/hello
    ```
    ## rbac
    ```
    k auth can-i get crd
    k auth can-i '*' '*' --all-namespaces
    # list what a sa 's rbac
    k auth can-i --list --as system:serviceaccount:datadog:datadog
    k auth can-i get crd --as system:serviceaccount:velero:velero
    k auth can-i '*' '*' --as system:serviceaccount:default:remote-admin-sa --all-namespaces
    # list what I can do
    k auth can-i get crd
    k auth can-i '*' '*' --all-namespaces
    # with krew plugins
  9. pydevops revised this gist May 22, 2023. 1 changed file with 5 additions and 0 deletions.
    5 changes: 5 additions & 0 deletions kubectl.md
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    @@ -38,6 +38,11 @@ kubectl get pods -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{ran
    kubectl get svc -l component=elasticsearch,role=client -o jsonpath='{..ip}'
    grace=$(kubectl get po cassandra-0 -o=jsonpath=‘{.spec.terminationGracePeriodSeconds}’)
    grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..terminationGracePeriodSeconds}'
    # list node instance type, zone, ami
    echo "***list karpenter nodes ami"
    kubectl get nodes -L karpenter.k8s.aws/instance-ami-id -l karpenter.sh/provisioner-name=default -o custom-columns="Name:.metadata.name,InstanceType:.metadata.labels.node\.kubernetes\.io/instance-type,\
    Zone:.metadata.labels.topology\.kubernetes\.io/zone,Ami:.metadata.labels.karpenter\.k8s\.aws/instance-ami-id"
    ```

    ## custom-columns
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    * https://karlkfi.medium.com/compendium-of-kubernetes-application-deployment-tools-80a828c91e8f
    * https://krew.sigs.k8s.io/plugins/

    ## imperative
    * https://kubernetes.io/docs/tasks/manage-kubernetes-objects/imperative-command/
    * https://medium.com/better-programming/kubernetes-tips-create-pods-with-imperative-commands-in-1-18-62ea6e1ceb32
    * https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde
    * https://blog.heptio.com/using-kubectl-to-jumpstart-a-yaml-file-heptioprotip-6f5b8a63a3ea

    ## JSONAPTH

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    ```
    # loop with range
    # list pods
    # list pod's name
    k get po -o jsonpath='{range .items[*]}{.metadata.name}{"\n"}{end}'
    k get po -o jsonpath={.items..metadata.name}
    # list node names and cpu capacity
    k get nodes -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.capacity.cpu}{"\n"}{end}'
    kubectl get pods -o jsonpath="{..image}"
    # list image
    kubectl get pods -o jsonpath="{..image}" | tr -s '[[:space:]]' '\n' | sort | uniq
    kubectl get pods -o jsonpath="{.items[*].spec.containers[*].image}"
    kubectl get pods -o jsonpath='{.items[*].status.podIP}'
    kubectl get nodes -o jsonpath='{.items[*].spec.podCIDR}' | tr " " "\n"
    kubectl get nodes -o json | jq '.items[] | .spec'
    kubectl get no -o go-template='{{range .items}}{{.spec.podCIDR}}{{"\n"}}{{end}}'
    kubectl get pods -o jsonpath='{.items[*].status.podIP}'
    kubectl get pods -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}'
    kubectl get pods -o go-template --template="{{range .items}}{{range .spec.containers}}{{.image}} {{end}}{{end}}"
    kubectl get svc -l component=elasticsearch,role=client -o jsonpath='{..ip}'
    kubectl get pods --all-namespaces -o jsonpath="{..image}" |\
    tr -s '[[:space:]]' '\n' |\
    sort |\
    uniq -c
    kubectl get svc -l component=elasticsearch,role=client -o jsonpath='{..ip}'
    grace=$(kubectl get po cassandra-0 -o=jsonpath=‘{.spec.terminationGracePeriodSeconds}’)
    grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..terminationGracePeriodSeconds}'
    ```

    ## custom-columns
    ```
    # same query in jsonpath
    k get po -o custom-columns='POD_NAME:.metadata.name'
    k get po -o custom-columns='POD_NAME:metadata.name'
    # same query as in jsonpath for node and cpu counts
    k get nodes -o custom-columns="NODE:.metadata.name,CPU:.status.capacity.cpu"
    # node name
    k get nodes -o custom-columns=NAME:.metadata.name
    # pod name
  12. pydevops revised this gist Dec 14, 2022. 1 changed file with 4 additions and 3 deletions.
    7 changes: 4 additions & 3 deletions kubectl.md
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    @@ -3,13 +3,12 @@
    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)

    ## cheatsheet
    * https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
    * https://learncloudnative.com/blog/2022-05-10-kubectl-tips
    * https://itnext.io/tips-tricks-for-cka-ckad-and-cks-exams-cc9dade1f76d
    * https://cloud.google.com/anthos/gke/docs/on-prem/reference/cheatsheet
    * https://medium.com/flant-com/kubectl-commands-and-tips-7b33de0c5476
    * https://prefetch.net/blog/2019/10/16/the-beginners-guide-to-creating-kubernetes-manifests/
    * https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
    * https://learnk8s.io/blog/kubectl-productivity/
    * https://medium.com/faun/kubectl-commands-cheatsheet-43ce8f13adfb
    * https://gist.github.com/so0k/42313dbb3b547a0f51a547bb968696ba
    * https://www.atomiccommits.io/everything-useful-i-know-about-kubectl
    @@ -217,8 +216,10 @@ k access-matrix --sa kube-system:kube-state-metrics
    ```
    ## find top resource hungry pod
    ```
    # cpu
    # pod sort by cpu
    k top pods --sort-by=cpu --no-headers
    # container sort by memory
    k top pods --containers --sort-by=memory
    kubectl top pods -A --no-headers | sort -rn -k 3
    # memory
    kubectl top pods -A --no-headers | sort -rn -k 4
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    ## cool gear to have
    * https://karlkfi.medium.com/a-select-list-of-kubernetes-tools-38249fc27155
    * https://karlkfi.medium.com/compendium-of-kubernetes-application-deployment-tools-80a828c91e8f
    * https://medium.com/free-code-camp/how-to-set-up-a-serious-kubernetes-terminal-dd07cab51cd4
    * https://krew.sigs.k8s.io/plugins/

    ## imperative
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    ```
    # loop with range
    # list pods
    k get po -o jsonpath='{range .items[*]}{.metadata.name}{"\n"}{end}'
    # list node names and cpu capacity
    k get nodes -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.capacity.cpu}{"\n"}{end}'
    kubectl get pods -o jsonpath="{..image}"
    @@ -54,6 +57,8 @@ grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..ter

    ## custom-columns
    ```
    # same query in jsonpath
    k get po -o custom-columns='POD_NAME:.metadata.name'
    # same query as in jsonpath for node and cpu counts
    k get nodes -o custom-columns="NODE:.metadata.name,CPU:.status.capacity.cpu"
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    @@ -54,18 +54,27 @@ grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..ter

    ## custom-columns
    ```
    # same query as in jsonpath for node and cpu counts
    k get nodes -o custom-columns="NODE:.metadata.name,CPU:.status.capacity.cpu"
    # node name
    k get nodes -o custom-columns=NAME:.metadata.name
    # pod name
    k get po -o custom-columns=NAME:.metadata.name
    # image name
    k get po -o custom-columns='IMAGE:spec.containers[*].image'
    # list container image and k8s-app lable value in kube-system
    k get deployment -o custom-columns='IMAGE:.spec.template.spec.containers[*].image,LABEL:.spec.template.metadata.labels.k8s-app' -n kube-system
    ```
    ## sort-by

    ```
    # implict range or items[*]
    k get nodes --sort-by=".metadata.name"
    k get nodes --sort-by=".status.capacity.cpu"
    k get po --sort-by=.spec.nodeName -o wide
    k get po --sort-by=".metadata.creationTimestamp"
    k get pv --sort-by=.spec.capacity.storage -o custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
  16. pydevops revised this gist Dec 13, 2022. 1 changed file with 47 additions and 37 deletions.
    84 changes: 47 additions & 37 deletions kubectl.md
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    @@ -26,6 +26,53 @@
    * https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde
    * https://blog.heptio.com/using-kubectl-to-jumpstart-a-yaml-file-heptioprotip-6f5b8a63a3ea

    ## JSONAPTH

    ```
    # loop with range
    k get nodes -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.capacity.cpu}{"\n"}{end}'
    kubectl get pods -o jsonpath="{..image}"
    kubectl get pods -o jsonpath="{.items[*].spec.containers[*].image}"
    kubectl get pods -o jsonpath='{.items[*].status.podIP}'
    kubectl get nodes -o jsonpath='{.items[*].spec.podCIDR}' | tr " " "\n"
    kubectl get nodes -o json | jq '.items[] | .spec'
    kubectl get no -o go-template='{{range .items}}{{.spec.podCIDR}}{{"\n"}}{{end}}'
    kubectl get pods -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}'
    kubectl get pods -o go-template --template="{{range .items}}{{range .spec.containers}}{{.image}} {{end}}{{end}}"
    kubectl get svc -l component=elasticsearch,role=client -o jsonpath='{..ip}'
    kubectl get pods --all-namespaces -o jsonpath="{..image}" |\
    tr -s '[[:space:]]' '\n' |\
    sort |\
    uniq -c
    grace=$(kubectl get po cassandra-0 -o=jsonpath=‘{.spec.terminationGracePeriodSeconds}’)
    grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..terminationGracePeriodSeconds}'
    ```

    ## custom-columns
    ```
    # node name
    k get nodes -o custom-columns=NAME:.metadata.name
    # pod name
    k get po -o custom-columns=NAME:.metadata.name
    # image name
    k get po -o custom-columns='IMAGE:spec.containers[*].image'
    k get deployment -o custom-columns='IMAGE:.spec.template.spec.containers[*].image,LABEL:.spec.template.metadata.labels.k8s-app' -n kube-system
    ```
    ## sort-by

    ```
    # implict range or items[*]
    k get po --sort-by=.spec.nodeName -o wide
    k get po --sort-by=".metadata.creationTimestamp"
    k get pv --sort-by=.spec.capacity.storage -o custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    ```


    ## clean up pods
    Did this for cleaning up pods with not in Running state such as Terminated

    @@ -106,43 +153,6 @@ echo $(kubectl get secret/terraform -o jsonpath="{.data['terraform\.json']}" | b
    * https://gist.github.com/so0k/42313dbb3b547a0f51a547bb968696ba
    * https://kubernetes.io/docs/tasks/access-application-cluster/list-all-running-container-images/

    ```
    grace=$(kubectl get po cassandra-0 -o=jsonpath=‘{.spec.terminationGracePeriodSeconds}’)
    grace=$(kubectl get sts -l component=elasticsearch,role=data -o jsonpath='{..terminationGracePeriodSeconds}'
    kubectl get svc -l component=elasticsearch,role=client -o jsonpath='{..ip}'
    kubectl get pods -o jsonpath="{..image}"
    kubectl get pods -o jsonpath="{.items[*].spec.containers[*].image}"
    kubectl get pods -o jsonpath='{.items[*].status.podIP}'
    kubectl get nodes -o jsonpath='{.items[*].spec.podCIDR}' | tr " " "\n"
    kubectl get nodes -o json | jq '.items[] | .spec'
    kubectl get no -o go-template='{{range .items}}{{.spec.podCIDR}}{{"\n"}}{{end}}'
    kubectl get pods -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}'
    kubectl get pods -o go-template --template="{{range .items}}{{range .spec.containers}}{{.image}} {{end}}{{end}}"
    kubectl get pods --all-namespaces -o jsonpath="{..image}" |\
    tr -s '[[:space:]]' '\n' |\
    sort |\
    uniq -c
    ```
    ## custom-columns
    ```
    # node name
    k get nodes -o custom-columns=NAME:.metadata.name
    # pod name
    k get po -o custom-columns=NAME:.metadata.name
    # image name
    k get po -o custom-columns='IMAGE:spec.containers[*].image'
    k get pv --sort-by=.spec.capacity.storage -o custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    k get deployment -o custom-columns='IMAGE:.spec.template.spec.containers[*].image,LABEL:.spec.template.metadata.labels.k8s-app' -n kube-system
    ```
    ## sort-by

    ```
    kubectl get po --sort-by=.spec.nodeName -o wide
    kubectl get po --sort-by=".metadata.creationTimestamp"
    ```

    ## Get the TCP LB port and IP
    ```
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    ```
    ## custom-columns
    ```
    k get po -A -o=custom-columns='DATA:spec.containers[*].image'
    k get pv --sort-by=.spec.capacity.storage -o=custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    # node name
    k get nodes -o custom-columns=NAME:.metadata.name
    # pod name
    k get po -o custom-columns=NAME:.metadata.name
    # image name
    k get po -o custom-columns='IMAGE:spec.containers[*].image'
    k get pv --sort-by=.spec.capacity.storage -o custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    k get deployment -o custom-columns='IMAGE:.spec.template.spec.containers[*].image,LABEL:.spec.template.metadata.labels.k8s-app' -n kube-system
    ```
    ## sort-by
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    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)

    ## cheatsheet
    * https://learncloudnative.com/blog/2022-05-10-kubectl-tips
    * https://itnext.io/tips-tricks-for-cka-ckad-and-cks-exams-cc9dade1f76d
    * https://cloud.google.com/anthos/gke/docs/on-prem/reference/cheatsheet
    * https://medium.com/flant-com/kubectl-commands-and-tips-7b33de0c5476
  19. pydevops revised this gist Mar 9, 2022. 1 changed file with 1 addition and 1 deletion.
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    * https://karlkfi.medium.com/a-select-list-of-kubernetes-tools-38249fc27155
    * https://karlkfi.medium.com/compendium-of-kubernetes-application-deployment-tools-80a828c91e8f
    * https://medium.com/free-code-camp/how-to-set-up-a-serious-kubernetes-terminal-dd07cab51cd4
    * https://github.com/kubernetes-sigs/krew-index/blob/master/plugins.md
    * https://krew.sigs.k8s.io/plugins/

    ## imperative
    * https://kubernetes.io/docs/tasks/manage-kubernetes-objects/imperative-command/
  20. pydevops revised this gist Mar 9, 2022. 1 changed file with 6 additions and 24 deletions.
    30 changes: 6 additions & 24 deletions kubectl.md
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    @@ -71,32 +71,14 @@ kubectl api-resources --sort-by=kind
    # find out what is under the api group
    k api-resources --api-group apps
    NAME SHORTNAMES APIGROUP NAMESPACED KIND
    controllerrevisions apps true ControllerRevision
    daemonsets ds apps true DaemonSet
    deployments deploy apps true Deployment
    replicasets rs apps true ReplicaSet
    statefulsets sts apps true StatefulSet
    k api-resources --api-group extensions
    NAME SHORTNAMES APIGROUP NAMESPACED KIND
    ingresses ing extensions true Ingress
    k api-resources --api-group=batch
    NAME SHORTNAMES APIGROUP NAMESPACED KIND
    cronjobs cj batch true CronJob
    jobs batch true Job
    k api-resources --api-group=networking.k8s.io
    NAME SHORTNAMES APIGROUP NAMESPACED KIND
    ingressclasses networking.k8s.io false IngressClass
    ingresses ing networking.k8s.io true Ingress
    networkpolicies netpol networking.k8s.io true NetworkPolicy
    # so we have group networking.k8s.io from api-resource, version (v1) from api-version, now we can explain
    k explain ingress --api-version=networking.k8s.io/v1 --recursive
    NAME SHORTNAMES APIVERSION NAMESPACED KIND
    ingressclasses networking.k8s.io/v1 false IngressClass
    ingresses ing networking.k8s.io/v1 true Ingress
    networkpolicies netpol networking.k8s.io/v1 true NetworkPolicy
    # then we can explain with $APIVERSION
    k explain --api-version=$APIVERSION ingress --recursive
    k explain --api-version=apps/v1 deployment --recursive
    # for each "group/version" in the output above except for "api/v1"
  21. pydevops revised this gist Mar 9, 2022. 1 changed file with 2 additions and 1 deletion.
    3 changes: 2 additions & 1 deletion kubectl.md
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    @@ -58,7 +58,8 @@ kubectl config set-context --current --namespace=kube-system

    ## API
    * https://kubernetes.io/docs/tasks/administer-cluster/access-cluster-api/
    * api group https://kubernetes.io/docs/reference/using-api/api-overview/#api-groups
    * API group https://kubernetes.io/docs/reference/using-api/api-overview/#api-groups
    * API convention https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#api-conventions

    ```
    # Print the supported API group and its versions on the server, in the form of "group/version"
  22. pydevops revised this gist Mar 9, 2022. 1 changed file with 10 additions and 10 deletions.
    20 changes: 10 additions & 10 deletions kubectl.md
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    @@ -176,16 +176,6 @@ kubectl rollout resume deployment/hello
    # roll back
    kubectl rollout undo deployment/hello
    ```
    ## find top resource hungry pod
    ```
    # cpu
    k top pods --sort-by=cpu --no-headers
    kubectl top pods -A --no-headers | sort -rn -k 3
    # memory
    kubectl top pods -A --no-headers | sort -rn -k 4
    # top 1
    kubectl top pod --no-headers | grep -v NAME | sort -k 3 -nr | awk -F ' ' 'NR==1{print $1}'
    ```
    ## rbac
    ```
    k auth can-i get crd
    @@ -212,6 +202,16 @@ k who-can create customresourcedefinition
    k access-matrix --sa default:deployer
    k access-matrix --sa kube-system:kube-state-metrics
    ```
    ## find top resource hungry pod
    ```
    # cpu
    k top pods --sort-by=cpu --no-headers
    kubectl top pods -A --no-headers | sort -rn -k 3
    # memory
    kubectl top pods -A --no-headers | sort -rn -k 4
    # top 1
    kubectl top pod --no-headers | grep -v NAME | sort -k 3 -nr | awk -F ' ' 'NR==1{print $1}'
    ```

    ## metrics
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    @@ -179,12 +179,12 @@ kubectl rollout undo deployment/hello
    ## find top resource hungry pod
    ```
    # cpu
    k top pods --sort-by=cpu
    kubectl top pods -A | sort -rn -k 3
    k top pods --sort-by=cpu --no-headers
    kubectl top pods -A --no-headers | sort -rn -k 3
    # memory
    kubectl top pods -A | sort -rn -k 4
    kubectl top pods -A --no-headers | sort -rn -k 4
    # top 1
    kubectl top pod | grep -v NAME | sort -k 3 -nr | awk -F ' ' 'NR==1{print $1}'
    kubectl top pod --no-headers | grep -v NAME | sort -k 3 -nr | awk -F ' ' 'NR==1{print $1}'
    ```
    ## rbac
    ```
  24. pydevops revised this gist Mar 9, 2022. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion kubectl.md
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    @@ -99,7 +99,7 @@ k explain ingress --api-version=networking.k8s.io/v1 --recursive
    k explain --api-version=apps/v1 deployment --recursive
    # for each "group/version" in the output above except for "api/v1"
    kubectl get --raw /apis/group/version | jq -r '.resources[].kind'
    kubectl get --raw /apis/${group/version} | jq -r '.resources[].kind'
    kubectl get --raw /apis/apps/v1 | jq . -C | less -R
  25. pydevops revised this gist Mar 8, 2022. 1 changed file with 22 additions and 0 deletions.
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    @@ -212,4 +212,26 @@ k who-can create customresourcedefinition
    k access-matrix --sa default:deployer
    k access-matrix --sa kube-system:kube-state-metrics
    ```

    ## metrics
    * https://talkcloudlytome.com/raw-kubernetes-metrics-with-kubectl/
    * https://www.datadoghq.com/blog/how-to-collect-and-graph-kubernetes-metrics/

    ```
    # all nodes
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes | jq -C . | less -R
    # individual node
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes/$NODE_NAME
    # all pods
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/pods | jq . -C | less -R
    # individual pod
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/namespaces/$NS/pods/$POD
    # jq
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes \
    | jq '[.items [] | {nodeName: .metadata.name, nodeCpu: .usage.cpu, nodeMemory: .usage.memory}]'
    kubectl get --raw /apis/metrics.k8s.io/v1beta1/pods | jq . -C | less -R
    ```
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    * https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde
    * https://blog.heptio.com/using-kubectl-to-jumpstart-a-yaml-file-heptioprotip-6f5b8a63a3ea

    ## clean up pods
    Did this for cleaning up pods with not in Running state such as Terminated

    ```
    k get po --field-selector=status.phase!=Running -o custom-columns=":metadata.name" --no-headers | xargs kubectl delete po
    ```

    ## waitfor

    * https://vadosware.io/post/so-you-need-to-wait-for-some-kubernetes-resources/
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    * https://learnk8s.io/blog/kubectl-productivity/
    * https://medium.com/faun/kubectl-commands-cheatsheet-43ce8f13adfb
    * https://gist.github.com/so0k/42313dbb3b547a0f51a547bb968696ba
    * https://www.atomiccommits.io/everything-useful-i-know-about-kubectl

    ## cool gear to have
    * https://karlkfi.medium.com/a-select-list-of-kubernetes-tools-38249fc27155
    @@ -23,7 +24,9 @@
    * https://medium.com/better-programming/kubernetes-tips-create-pods-with-imperative-commands-in-1-18-62ea6e1ceb32
    * https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde
    * https://blog.heptio.com/using-kubectl-to-jumpstart-a-yaml-file-heptioprotip-6f5b8a63a3ea

    ## waitfor

    * https://vadosware.io/post/so-you-need-to-wait-for-some-kubernetes-resources/

    ## debug
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    ## custom-columns
    ```
    k get po -A -o=custom-columns='DATA:spec.containers[*].image'
    kubectl get pv --sort-by=.spec.capacity.storage -o=custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    k get pv --sort-by=.spec.capacity.storage -o=custom-columns="NAME:.metadata.name,CAPACITY:.spec.capacity.storage"
    k get deployment -o custom-columns='IMAGE:.spec.template.spec.containers[*].image,LABEL:.spec.template.metadata.labels.k8s-app' -n kube-system
    ```
    ## sort-by
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    * https://medium.com/better-programming/kubernetes-tips-create-pods-with-imperative-commands-in-1-18-62ea6e1ceb32
    * https://medium.com/bitnami-perspectives/imperative-declarative-and-a-few-kubectl-tricks-9d6deabdde
    * https://blog.heptio.com/using-kubectl-to-jumpstart-a-yaml-file-heptioprotip-6f5b8a63a3ea
    ## waitfor
    * https://vadosware.io/post/so-you-need-to-wait-for-some-kubernetes-resources/

    ## debug
    ```
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    ## reference
    * https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands
    * [how it works](https://github.com/jamiehannaford/what-happens-when-k8s)

    ## cheatsheet
    * https://itnext.io/tips-tricks-for-cka-ckad-and-cks-exams-cc9dade1f76d