Kubernetes叢集安裝及kubectl指令行大全

筆記本/桌上型電腦電腦的性能足夠強勁（記憶體不低于 8G），可以直接安裝 docker-desktop，并啟用其中内嵌的  Kubernetes  叢集，用做學習、測試，也可以用作日常開發。

下載下傳 docker-desktop

從 docker 下載下傳 docker-desktop (opens new window)，并完成安裝

啟用 Kubernetes 叢集

MAC

啟動 docker-desktop

打開 docker-desktop 的 preference 面闆

切換到 Kubernetes 标簽頁

并勾選啟動 Enable Kubernetes，點選 Apply

kubectl config view      

kubectl config get-contexts      

kubectl cluster-info      

kubectl get pods -o wide      

docker network inspect bridge      

[
    {
        "Name": "bridge",
        "Id": "e6a5227c83898fa2904259426de838145d62539d01fb7f3fe241f65db38a3c3b",
        "Created": "2020-12-30T02:51:44.917984338Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16",
                    "Gateway": "172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]      

另一種進入nginx容器的方法

kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] – [COMMAND] instead.

因為剛才建立的 nginx pod 裡隻有一個容器，是以我們就進入了那個。可如果nginx pod 裡有倆容器，預設隻會進第一個，如何進第二個呢？

kubectl describe pods nginx      

➜  pod-basic kubectl describe pods nginx
Name:         nginx
Namespace:    default
Priority:     0
Node:         docker-desktop/192.168.65.3
Start Time:   Wed, 30 Dec 2020 12:35:54 +0800
Labels:       app=nginx
Annotations:  <none>
Status:       Running
IP:           10.1.0.6
IPs:
  IP:  
Containers:
  nginx:
    Container ID:   docker://f4e45055b4b33430ecd775494c6bd8a8fe0c351ab1333016fcdc588182f40e41
    Image:          nginx
    Image ID:       docker-pullable://nginx@sha256:4cf620a5c81390ee209398ecc18e5fb9dd0f5155cd82adcbae532fec94006fb9
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Wed, 30 Dec 2020 12:40:42 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-tqpkf (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             True
  ContainersReady   True
  PodScheduled      True
Volumes:
  default-token-tqpkf:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-tqpkf
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason   Age   From     Message
  ----    ------   ----  ----     -------
  Normal  Pulled   60m   kubelet  Successfully pulled image "nginx" in 35.578083503s
  Normal  Created  60m   kubelet  Created container nginx
  Normal  Started  60m   kubelet  Started container nginx      

删除資源

# 删除一個配置檔案對應的資源對象
kubectl delete -f xxx.yaml       
# 删除名字為baz或foo的pod和service                  
kubectl delete pod,service baz foo   
# -l 參數可以删除包含指定label的資源對象                                        
kubectl delete pods,services -l name=myLabel   
# 強制删除一個pod，在各種原因pod一直terminate不掉的時候很有用 
kubectl delete pod foo --grace-period=0 --force       

kubectl delete pods imagename      

更新資源

# 将foo.yaml中描述的對象擴充為3個
kubectl scale --replicas=3 -f foo.yaml
# 增加description='my frontend'備注,已有保留不覆寫
kubectl annotate pods foo description='my frontend' 
# 增加status=unhealthy 标簽，已有則覆寫
kubectl label --overwrite pods foo status=unhealthy       

kubectl scale rs nginx --replicas=2 更新某 pod 内叢集數

建立資源

# 建立一個service，暴露 nginx 這個rc
kubectl expose deployment nginx-deployment --type=NodePort      

kubectl get svc

切換上下文

kubectl config use-context xxx 即可