Pod management

# Set up image acceleration 
cat /etc/docker/daemon.json

{
  "exec-opts": ["native.cgroupdriver=systemd"], # Here in k8s1.2 It is recommended to be consistent with this content when deploying versions above .
  "registry-mirrors": ["https://zzypv4yy.mirror.aliyuncs.com"]
}

#--dry-run Output pod Created yaml file 
[[email protected] ~]# kubectl run www --image=nginx --dry-run -o yaml
W0211 12:25:12.671160   43802 helpers.go:598] --dry-run is deprecated and can be replaced with --dry-run=client.
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: www
  name: www
spec:
  containers:
  - image: nginx
    name: www
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

[[email protected] ~]# kubectl config view
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.71.133:6443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    namespace: app01
    user: kubernetes-admin
  name: [email protected]
current-context: [email protected]
kind: Config
preferences: {}
users:
- name: kubernetes-admin
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

# see api Object and version 
[[email protected] ~]# kubectl api-resources
# see kube-sytem ns Medium pod Operation information 
[[email protected] ~]# kubectl get pods -o wide -n kube-system
NAME                                    READY   STATUS    RESTARTS        AGE     IP               NODE            NOMINATED NODE   READINESS GATES
coredns-6d8c4cb4d-5x5gq                 1/1     Running   8 (103m ago)    2d18h   10.244.0.31      k8s-master-01   <none>           <none>
coredns-6d8c4cb4d-m2gjp                 1/1     Running   8 (103m ago)    2d18h   10.244.0.30      k8s-master-01   <none>           <none>
etcd-k8s-master-01                      1/1     Running   10 (103m ago)   2d18h   192.168.71.133   k8s-master-01   <none>           <none>
kube-apiserver-k8s-master-01            1/1     Running   10 (103m ago)   2d18h   192.168.71.133   k8s-master-01   <none>           <none>
kube-controller-manager-k8s-master-01   1/1     Running   10 (103m ago)   2d18h   192.168.71.133   k8s-master-01   <none>           <none>
kube-flannel-ds-8tzbw                   1/1     Running   7 (101m ago)    2d18h   192.168.71.134   k8s-node-01     <none>           <none>
kube-flannel-ds-d6fpt                   1/1     Running   0               13h     192.168.71.135   k8s-node-02     <none>           <none>
kube-flannel-ds-p46hm                   1/1     Running   12 (102m ago)   2d18h   192.168.71.133   k8s-master-01   <none>           <none>
kube-proxy-kfjhw                        1/1     Running   0               13h     192.168.71.135   k8s-node-02     <none>           <none>
kube-proxy-p5gws                        1/1     Running   5 (101m ago)    2d18h   192.168.71.134   k8s-node-01     <none>           <none>
kube-proxy-tmc9w                        1/1     Running   8 (103m ago)    2d18h   192.168.71.133   k8s-master-01   <none>           <none>
kube-scheduler-k8s-master-01            1/1     Running   10 (103m ago)   2d18h   192.168.71.133   k8s-master-01   <none>           <none>
# see pod Content options 
[[email protected] ~]# kubectl explain pod.spec
# see pod label 
[[email protected] ~]# kubectl get pods --show-labels
# see pod Information 
[[email protected] ~]# kubectl describe pod www
# see node Information 
[[email protected] ~]# kubectl describe node k8s-node-01
# modify pod Information 
[[email protected] ~]# kubectl edit pod www
# see event
[[email protected] ~]# kubectl get event
# Delete pod
[[email protected] ~]# kubectl delete pod www --grace-period=0 --force
# stay pod Middle execution command 
[[email protected] ~]# kubectl exec -it www -- ls /
bin   docker-entrypoint.d   home   media  proc  sbin  tmp
boot  docker-entrypoint.sh  lib    mnt    root  srv   usr
dev   etc                   lib64  opt    run   sys   var
# Copy files from the host to pod Corresponding catalogue 
[[email protected] ~]# kubectl cp /etc/hosts www:/tmp
[[email protected] ~]# kubectl exec -it www -- ls /tmp
hosts
# from pod Copy the file to the host 
[[email protected] ~]# kubectl cp www:/etc/hosts hosts.bak
[[email protected] ~]# cat hosts.bak
# Kubernetes-managed hosts file.
127.0.0.1       localhost
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe00::1 ip6-allnodes
fe00::2 ip6-allrouters
10.244.1.15     www
# Enter designated pod Medium container
[[email protected] ~]# kubectl exec -it www -c www -- ls /tmp
hosts
# label 
[[email protected] ~]# kubectl label nodes --all app=trust
[[email protected] ~]# kubectl label nodes --all app-
[[email protected] ~]# kubectl get pods -l app=www
#Taints
[[email protected] ~]# kubectl taint node k8s-node-01 xx=yy:NoSchedule
[[email protected] ~]# kubectl describe node k8s-node-01 | grep Taints
Taints:             xx=yy:NoSchedule
## test Taint
[[email protected] ~]# kubectl run pod www --image=nginx --dry-run -o yaml
W0211 17:04:11.389901   16593 helpers.go:598] --dry-run is deprecated and can be replaced with --dry-run=client.
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: pod
  name: pod
spec:
  containers:
  - args:
    - www
    image: nginx
    name: pod
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}
## Copy the above content to www02.yaml And create pod, To the only one node The node is on Taint, It makes it impossible to schedule 
[[email protected] ~]# kubectl apply -f www02.yaml
pod/pod created
[[email protected] ~]# kubectl get pods
NAME   READY   STATUS    RESTARTS   AGE
pod    0/1     Pending   0          3s
## modify www02.yaml
[[email protected] ~]# cat www02.yaml
apiVersion: v1
kind: Pod
metadata:
  labels:
    run: pod
  name: www02
spec:
  containers:
  - image: nginx
    name: nginx-01
  tolerations:
  - effect: NoSchedule
    key: xx
    value: yy
    operator: Equal
  dnsPolicy: ClusterFirst
  restartPolicy: Always
[[email protected] ~]# kubectl get pods
NAME    READY   STATUS    RESTARTS   AGE
www02   1/1     Running   0          42s
## Remove Taint
[[email protected] ~]# kubectl taint node k8s-node-01 xx:NoSchedule-
node/k8s-node-01 untainted