常用命令
kubectl logs mypod --previous
kubectl delete pod -n kube-system test-q2ngc --grace-period=180
kubectl delete pod <pod> --force --grace-period=0
kubectl exec -it -n monitoring test-f7bdb9769-ctxbs -- env COLUMNS=210 LINES=60 bash
kubectl scale deployments/kubernetes-bootcamp --replicas=3
kubectl rollout status ds/<daemonset-name> # status
kubectl rollout undo deployments/kubernetes-bootcamp #回退
kubectl get --raw "/apis/metrics.k8s.io/v1beta1/nodes" | jq
kubectl -v=8 top node
kubectl -v=8 get svc kubernetes
kubectl apply -f ds.yaml --dry-run -o go-template='{{.spec.updateStrategy.type}}{{"\\\\n"}}'
# doc
kubectl api-resources
kubectl explain statefulsets
journalctl -xef -u kubelet
# 打印使用的api
kubectl get pod -v=9
资源使用情况
kubectl get deployments.apps -n xxx -o custom-columns=:.metadata.namespace,:.metadata.name,:.spec.replicas,:.spec.template.spec.containers[0].resources.limits.cpu,:.spec.template.spec.containers[0].resources.limits.memory
运行测试 pod
kubectl run busytest --rm -it --image=busybox sh
kubectl run dig --rm -it --image=docker.io/azukiapp/dig /bin/sh
kubectl run centos --rm -it --image=centos bash
查看某个app pod分布情况
kubectl get pods -o wide -l app="nginx-server" | awk '{print $7}'| \\
awk '{ count[$0]++ }
END {
printf("%-35s: %s\\n","Word","Count");
for(ind in count){
printf("%-35s: %d\\n",ind,count[ind]);
}
}'
label master
# label
kubectl get node --show-labels
kubectl label node yztest-ops-k8s24v8-yz role=master
kubectl label node yztest-ops-k8s24v8-yz role-
# spec.template.spec.nodeSelector: node label位置
# 标记为node
kubectl label node hostname node-role.kubernetes.io/node=
# master 充当node
kubectl taint node yztest-ops-k8s24v8-yz node-role.kubernetes.io/master-
# 恢复master角色
kubectl taint node yztest-ops-k8s24v8-yz node-role.kubernetes.io/master="":NoSchedule
k8s自动补全
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc
patch
如果一个容器已经在运行，这时需要对一些容器属性进行修改，又不想删除容器，或不方便通过replace的方式进行更新。kubernetes还提供了一种在容器运行时，直接对容器进行修改的方式，就是patch命令。 如前面创建pod的label是app=nginx-2，如果在运行过程中，需要把其label改为app=nginx-3，这patch命令如下：
kubectl patch pod rc-nginx-2-kpiqt -p '{"metadata":{"labels":{"app":"nginx-3"}}}'
deployment
rolling-update
rolling-update是一个非常重要的命令，对于已经部署并且正在运行的业务，rolling-update提供了不中断业务的更新方式。rolling-update每次起一个新的pod，等新pod完全起来后删除一个旧的pod，然后再起一个新的pod替换旧的pod，直到替换掉所有的pod。
rolling-update需要确保新的版本有不同的name，Version和label，否则会报错 。
kubectl rolling-update rc-nginx-2 -f rc-nginx.yaml
如果在升级过程中，发现有问题还可以中途停止update，并回滚到前面版本
kubectl rolling-update rc-nginx-2 —rollback
scale
kubectl scale --replicas=3 rs/foo # Scale a replicaset named 'foo' to 3
kubectl scale --replicas=3 -f foo.yaml # Scale a resource specified in "foo.yaml" to 3
kubectl scale --current-replicas=2 --replicas=3 deployment/mysql # If the deployment named mysql's current size is 2, scale mysql to 3
kubectl scale --replicas=5 rc/foo rc/bar rc/baz # Scale multiple replication controllers
rollout
kubectl rollout history deployment/frontend # Check the history of deployments including the revision
kubectl rollout undo deployment/frontend # Rollback to the previous deployment
kubectl rollout undo deployment/frontend --to-revision=2 # Rollback to a specific revision
kubectl rollout status -w deployment/frontend # Watch rolling update status of "frontend" deployment until completion
kubectl rollout restart deployment/frontend # Rolling restart of the "frontend" deployment
pod 与主机文件传输
kubectl cp foo-pod:/var/log/foo.log foo.log
kubectl cp localfile foo-pod:/etc/remotefile
kubeadm
kubeadm config print init-defaults
kubeadm config view
快速查看pid的容器名字
podinfo() {
CID=$(cat /proc/$1/cgroup | awk -F '/' '{print $5}')
CID=$(echo ${CID:7:10})
crictl inspect $CID | jq '.status.labels["io.kubernetes.pod.name"]'
}
增加到~/.bashrc
# podinfo 16529
"test-6cc546b5-75q9n"
另一种方法
#!/bin/bash
forid=$(ps -efl|grep log4j-core|grep -v grep|awk '{print $4}'|xargs -i pstree -sg {} |awk 'NR==1{print $0}'|grep -E -o "[0-9]{1,10}"|grep -v ^1)
for I in $forid; do
docker ps -q | xargs docker inspect --format '{{.State.Pid}}, {{.Name}}' | grep "$I"|grep -v formatMsgNoLookups;
done
nsenter
快速脚本，需进入进入pod所在node,增加下面函数到~/.bashrc
function e() {
set -eu
ns=${2-"default"}
pod=`kubectl -n $ns describe pod $1 | grep -A10 "^Containers:" | grep -Eo 'docker://.*$' | head -n 1 | sed 's/docker:\\/\\/\\(.*\\)$/\\1/'`
pid=`docker inspect -f {{.State.Pid}} $pod`
echo "entering pod netns for $ns/$1"
cmd="nsenter -n --target $pid"
echo $cmd
$cmd
}
进入pod所在netns
e istio-galley-58c7c7c646-m6568 istio-system
e proxy-5546768954-9rxg6 # 省略 NAMESPACE 默认为 default
tcpdump -i eth0 -w test.pcap port 80
原文地址： Kubernetes 问题定位技巧：容器内抓包
metrics
cadvisor
kubectl get --raw /api/v1/nodes/10.66.240.101/proxy/metrics/cadvisor
kube-apiserver
kubectl get --raw /metrics
