Category: kubernetes

kubectl custom query to get cpu , memory request and limit

kubectl get deploy -A -o=custom-columns='Namespace:.metadata.namespace,Name:.metadata.name,Request_CPU:.spec.template.spec.containers[0].resources.requests.cpu,Limit_CPU:.spec.template.spec.containers[0].resources.limits.cpu,Request_Memory:.spec.template.spec.containers[0].resources.requests.memory,Limit_Memory:.spec.template.spec.containers[0].resources.limits.memory' | sed 1d | tr -s '[:blank:]' ','

kubect replace variabe

deployments=$(kubectl get deploy | awk '{print $1}' | sed 1d)

for deploy in $deployments
do
    deploy_raw_yml=$(kubectl get deploy $deploy -o yaml)
    kubectl get deploy $deploy -o yaml > _tmp_store.yml
    value_to_be_replaced=$(kubectl get deploy $deploy -o yaml | grep -A 1 'NEW_RELIC_APP_NAME' | grep value | awk -F 'value: ' '{print $2}')
    echo "value_to_be_replaced: $value_to_be_replaced"
    if [[ $value_to_be_replaced == "" ]]; then
        echo "=====================$deploy no change =========================="
    else
        replaced_value=$(echo $value_to_be_replaced | sed 's/stage/perf/g')
         echo "replaced_value: $replaced_value"
        cat _tmp_store.yml| sed "s/$value_to_be_replaced/$replaced_value/g"  | kubectl apply -f -
        echo "=====================$deploy done =========================="
    fi
    
done

• Enable feature gate InPlacePodVerticalScaling

/etc/kubernetes/manifests/kube-apiserver.yaml

nginx.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: nginx
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx
        resizePolicy:
        - resourceName: cpu
          restartPolicy: NotRequired
        - resourceName: memory
          restartPolicy: NotRequired
        resources:
          limits:
            memory: "100Mi"
            cpu: "100m"
          requests:
            memory: "100Mi"
            cpu: "100m"

patch.yml [only applied to pod]

kubectl patch pod nginx-94675f6cf-9bxzj --patch '{"spec":{"containers":[{"name":"nginx", "resources":{"requests":{"cpu":"200m"}, "limits":{"cpu":"200m"}}}]}}'

scale down deploy on weeknend:

####scale down####
namespaces="test,test2"
IFS=","

for namespace in $namespaces
do
    deployments=$(kubectl get deploy -n $namespace | grep -v '0/0' | awk '{print $1}' | sed 1d | tr '\n' ' ')
    IFS=" "
    for deploy in $deployments
    do
        replicas="$(kubectl get deploy $deploy -o=custom-columns='REPLICAS:spec.replicas' -n $namespace | sed 1d | tr '\n' ' ')"
        echo "namespace: $namespace deploy: $deploy replicas: $replicas"
        kubectl label deploy $deploy weekdays-replicas=$replicas -n $namespace --overwrite=true
        kubectl scale --replicas=0 statefulset $deploy -n "$namespace" || true
    done
done

scale-up:

####scale up####
namespaces="test,test2"
IFS=","
for namespace in $namespaces
do
    deployments=$(kubectl get deploy -n $namespace | awk '{print $1}' | sed 1d | tr '\n' ' ')
    IFS=" "
    for deploy in $deployments
    do
        replicas="$(kubectl get deploy $deploy -o=custom-columns='REPLICAS:metadata.labels.weekdays-replicas' -n $namespace | sed 1d | tr '\n' ' ')"
        echo "kubectl scale --replicas=$replicas statefulset $deploy -n "$namespace" || true"
    done
done