管理K8S核心资源的三种基本方法:
- 陈述式管理方法–主要依赖命令行CLI工具进行管理
- 声明式管理方法–主要依赖统一资源配置清单( manifest）进行管理
- GUI式管理方法一主要依赖图形化操作界面(web页面）进行管理
image.png
~]# kubectl get namespace/ns
NAME STATUS AGE
default Active 21h
kube-node-lease Active 21h
kube-public Active 21h
kube-system Active 21h
~]# kubectl get all [-n default]
NAME READY STATUS RESTARTS AGE
pod/nginx-ds-4tt4m 1/1 Running 0 16h
pod/nginx-ds-9jcqb 1/1 Running 0 16h
pod/nginx-web-799b86bc9c-9b8mg 1/1 Running 0 16h
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 192.168.0.1 443/TCP 21h
service/nginx-web ClusterIP 192.168.131.242 80/TCP 16h
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/nginx-ds 2 2 2 2 2 16h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-web 1/1 1 1 16h
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-web-799b86bc9c 1 1 1 16h
~]# kubectl create ns app
namespace/app created
~]# kubectl create deployment nginx-dp --image=harbor.od.com/public/nginx:curl -n kube-public
deployment.apps/nginx-dp created
[[email protected] ~]# kubectl get deploy -n kube-public
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-dp 1/1 1 1 23s
[[email protected] ~]# kubectl get pods -n kube-public -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-dp-9c86cfc59-n9vfr 1/1 Running 0 51s 172.7.21.5 k8s7-21.host.com
[[email protected] ~]# kubectl describe deployment nginx-dp -n kube-public
Name: nginx-dp
Namespace: kube-public
CreationTimestamp: Sun, 27 Sep 2020 16:24:42 +0800
Labels: app=nginx-dp
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=nginx-dp
Replicas: 1 desired | 1 updated | 1 total | 1 available | 0 unavailable
StrategyType: RollingUpdate #滚动发布(更新策略)
MinReadySeconds: 0
RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=nginx-dp
Containers:
nginx:
Image: harbor.od.com/public/nginx:curl
Port:
Host Port:
Environment:
Mounts:
Volumes:
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
Progressing True NewReplicaSetAvailable
OldReplicaSets:
NewReplicaSet: nginx-dp-9c86cfc59 (1/1 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 5m35s deployment-controller Scaled up replica set nginx-dp-9c86cfc59 to 1
[[email protected] ~]# kubectl exec -it nginx-dp-9c86cfc59-n9vfr /bin/bash -n kube-public
[[email protected] ~]# watch -n 1 'kubectl describe deployment nginx-dp -n kube-public|grep -C 5 Event'
~]# kubectl delete pod nginx-dp-9c86cfc59-n9vfr -n kube-public [--force --grace-period=0]
使用watch观察pod重建状态变化
强制删除参数:--force --grace-period=0
[[email protected] ~]# kubectl delete deploy nginx-dp -n kube-public
deployment.extensions "nginx-dp" deleted
[[email protected] ~]# kubectl create deployment nginx-dp --image=harbor.od.com/public/nginx:curl -n kube-public
deployment.apps/nginx-dp created
[[email protected] ~]# kubectl get all -n kube-public
[[email protected] ~]# kubectl expose deployment nginx-dp --port=80 -n kube-public
service/nginx-dp exposed
[[email protected] ~]# kubectl get all -n kube-public
NAME READY STATUS RESTARTS AGE
pod/nginx-dp-9c86cfc59-84n55 1/1 Running 0 3m41s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/nginx-dp ClusterIP 192.168.204.85 80/TCP 18s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-dp 1/1 1 1 3m41s
NAME DESIRED CURRENT READY AGE
replicaset.apps/nginx-dp-9c86cfc59 1 1 1 3m41s
~]# curl 192.168.204.85
[[email protected] ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.204.85:80 nq
-> 172.7.22.7:80 Masq 1 0 1
[[email protected] ~]# kubectl scale deployment nginx-dp --replicas=2 -n kube-public
deployment.extensions/nginx-dp scaled
[[email protected] ~]# kubectl get pods -n kube-public
NAME READY STATUS RESTARTS AGE
nginx-dp-9c86cfc59-84n55 1/1 Running 0 7m21s
nginx-dp-9c86cfc59-ghgg8 1/1 Running 0 14s
TCP 192.168.204.85:80 nq
-> 172.7.21.5:80 Masq 1 0 0
-> 172.7.22.7:80 Masq 1 0 0
[[email protected] ~]# kubectl describe svc nginx-dp -n kube-public
Name: nginx-dp
Namespace: kube-public
Labels: app=nginx-dp
Annotations:
Selector: app=nginx-dp
Type: ClusterIP
IP: 192.168.204.85
Port: 80/TCP
TargetPort: 80/TCP
Endpoints: 172.7.21.5:80,172.7.22.7:80
Session Affinity: None
Events:
image.png
[[email protected] ~]# kubectl get daemonset -n default
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
nginx-ds 2 2 2 2 2 17h
daemonset这种控制器会让每个运算节点都要运行一份
[[email protected] ~]# kubectl expose daemonset -n default nginx-ds --port=888
error: cannot expose a DaemonSet.extensions
不允许给daemonset控制器创建svc
image.png
1.获取统一资源配置清单
[[email protected] ~]# kubectl get pods -n kube-public
NAME READY STATUS RESTARTS AGE
nginx-dp-9c86cfc59-84n55 1/1 Running 0 23m
nginx-dp-9c86cfc59-ghgg8 1/1 Running 0 16m
[[email protected] ~]# kubectl get pods nginx-dp-9c86cfc59-ghgg8 -o yaml -n kube-public
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: "2020-09-27T09:27:00Z"
generateName: nginx-dp-9c86cfc59-
labels:
app: nginx-dp
pod-template-hash: 9c86cfc59
name: nginx-dp-9c86cfc59-ghgg8
namespace: kube-public
ownerReferences:
- apiVersion: apps/v1
blockOwnerDeletion: true
controller: true
kind: ReplicaSet
name: nginx-dp-9c86cfc59
uid: a68e29e0-98ba-4270-93ae-8d14c0b6de64
resourceVersion: "109194"
selfLink: /api/v1/namespaces/kube-public/pods/nginx-dp-9c86cfc59-ghgg8
uid: 76438ce3-058e-4b48-b15d-9b68731ddd37
spec:
containers:
- image: harbor.od.com/public/nginx:curl
imagePullPolicy: IfNotPresent
name: nginx
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /var/run/secrets/kubernetes.io/serviceaccount
name: default-token-zqxm4
readOnly: true
dnsPolicy: ClusterFirst
enableServiceLinks: true
nodeName: k8s7-21.host.com
priority: 0
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
serviceAccount: default
serviceAccountName: default
terminationGracePeriodSeconds: 30
tolerations:
- effect: NoExecute
key: node.kubernetes.io/not-ready
operator: Exists
tolerationSeconds: 300
- effect: NoExecute
key: node.kubernetes.io/unreachable
operator: Exists
tolerationSeconds: 300
volumes:
- name: default-token-zqxm4
secret:
defaultMode: 420
secretName: default-token-zqxm4
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2020-09-27T09:27:00Z"
status: "True"
type: Initialized
- lastProbeTime: null
lastTransitionTime: "2020-09-27T09:27:02Z"
status: "True"
type: Ready
- lastProbeTime: null
lastTransitionTime: "2020-09-27T09:27:02Z"
status: "True"
type: ContainersReady
- lastProbeTime: null
lastTransitionTime: "2020-09-27T09:27:00Z"
status: "True"
type: PodScheduled
containerStatuses:
- containerID: docker://1c2f1e9f15b0450f9bd84b7478550d04479d4f48d94e2b43c1b2e48f542a4bcf
image: harbor.od.com/public/nginx:curl
imageID: docker-pullable://harbor.od.com/public/nginx@sha256:9fb052e40b572765bca65cf43cbe6a8d62053361afcbac0e69999f61ab72c6d5
lastState: {}
name: nginx
ready: true
restartCount: 0
state:
running:
startedAt: "2020-09-27T09:27:01Z"
hostIP: 10.4.7.21
phase: Running
podIP: 172.7.21.5
qosClass: BestEffort
startTime: "2020-09-27T09:27:00Z"
查看SVC
[[email protected] ~]# kubectl get svc -n kube-public
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx-dp ClusterIP 192.168.204.85 80/TCP 22m
[[email protected] ~]# kubectl get svc nginx-dp -o yaml -n kube-public
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2020-09-27T09:23:16Z"
labels:
app: nginx-dp
name: nginx-dp
namespace: kube-public
resourceVersion: "108854"
selfLink: /api/v1/namespaces/kube-public/services/nginx-dp
uid: a8cd589a-98b8-4ac4-9bbe-50af51e06f85
spec:
clusterIP: 192.168.204.85
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: nginx-dp
sessionAffinity: None
type: ClusterIP
status:
loadBalancer: {}
点读机专用命令：
[[email protected] ~]# kubectl explain service.metadata
[[email protected] ~]# cat nginx-ds-svc.yaml
apiVersion: v1
kind: Service
metadata:
labels:
app: nginx-ds
name : nginx-ds
namespace: default
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: nginx-ds
type: ClusterIP
[[email protected] ~]# kubectl create/apply -f nginx-ds-svc.yaml
service/nginx-ds created
[[email protected] ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 192.168.0.1 443/TCP 23h
nginx-ds ClusterIP 192.168.90.55 80/TCP 22s
nginx-web ClusterIP 192.168.131.242 80/TCP 18h
[[email protected] ~]# kubectl get svc nginx-ds -o yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2020-09-27T10:03:46Z"
labels:
app: nginx-ds
name: nginx-ds
namespace: default
resourceVersion: "112350"
selfLink: /api/v1/namespaces/default/services/nginx-ds
uid: a69781d2-6d92-4f39-87a6-19ddb454cef5
spec:
clusterIP: 192.168.90.55
ports:
- port: 80 #对外暴露的端口
protocol: TCP
targetPort: 80 #容器内的端口
selector:
app: nginx-ds
sessionAffinity: None
type: ClusterIP
status:
loadBalancer: {}
在线修改资源配置清单：
[[email protected] ~]# kubectl edit svc nginx-ds
离线修改：
vim nginx-ds-svc.yaml
kubectl apply -f ....
[[email protected] ~]# kubectl delete svc nginx-ds
service "nginx-ds" deleted
[[email protected] ~]# kubectl delete -f nginx-ds-svc.yaml