k8s官網基礎知識入門教程

時間 2019-12-05

標籤 k8s 基礎知識入門教程简体版

原文原文鏈接

官網連接爲 https://kubernetes.io/docs/tutorials/kubernetes-basics/node

基礎操做環境爲minikubelinux

常見基礎命令

查看基礎的一些信息git

# 查看版本
(oracle) ➜  cdss_db git:(dameng) kubectl version
Client Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.0", GitCommit:"fc32d2f3698e36b93322a3465f63a14e9f0eaead", GitTreeState:"clean", BuildDate:"2018-03-26T16:55:54Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.0", GitCommit:"fc32d2f3698e36b93322a3465f63a14e9f0eaead", GitTreeState:"clean", BuildDate:"2018-03-26T16:44:10Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}


# 查看節點
(oracle) ➜  cdss_db git:(dameng) kubectl get nodes
NAME       STATUS    ROLES     AGE       VERSION
minikube   Ready     master    23h       v1.10.0

PODS/DEPLOYMENTS

建立一個pod（因爲網絡問題，須要提早將image導入到minikube的機器中）docker

# 建立pod
(oracle) ➜  cdss_db git:(dameng) kubectl run kubernetes-bootcamp --image=gcr.io/hello-minikube-zero-install/hello-node:latest --port=8080 --image-pull-policy=Never
deployment.apps "kubernetes-bootcamp" created

# 查看pod
(oracle) ➜  cdss_db git:(dameng) kubectl get pods
NAME                                   READY     STATUS    RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running   0          5s

# 查看deployment
(oracle) ➜  cdss_db git:(dameng) kubectl get deployments
NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-bootcamp   1         1         1            1           19m

# 將服務暴露到外網（相對於k8s的內部網）環境
(oracle) ➜  cdss_db git:(dameng) kubectl proxy
Starting to serve on 127.0.0.1:8001

# 測試----查看相關的接口
➜  minikube curl 127.0.0.1:8001/version
{
  "major": "1",
  "minor": "10",
  "gitVersion": "v1.10.0",
  "gitCommit": "fc32d2f3698e36b93322a3465f63a14e9f0eaead",
  "gitTreeState": "clean",
  "buildDate": "2018-03-26T16:44:10Z",
  "goVersion": "go1.9.3",
  "compiler": "gc",
  "platform": "linux/amd64"
}%

# 測試----測試對應接口
➜  minikube curl 127.0.0.1:8001/api/v1/namespaces/default/pods/kubernetes-bootcamp-85459f8c6c-9jgfl/proxy/
Hello World!%

# 停止proxy
ctrl+c 便可中止

查看pod的詳細信息shell

# 查看pod信息
➜  ~ kubectl describe pods
Name:           kubernetes-bootcamp-85459f8c6c-9jgfl
Namespace:      default
Node:           minikube/10.0.2.15
Start Time:     Tue, 19 Mar 2019 14:04:18 +0800
Labels:         pod-template-hash=4101594727
                run=kubernetes-bootcamp
Annotations:    <none>
Status:         Running
IP:             172.17.0.5
Controlled By:  ReplicaSet/kubernetes-bootcamp-85459f8c6c
Containers:
  kubernetes-bootcamp:
    Container ID:   docker://9ad04cae7f054805acfe9af452210bca960c44b673c2e837e9c39cf70f40a717
    Image:          gcr.io/hello-minikube-zero-install/hello-node:latest
    Image ID:       docker://sha256:40da0f31e97619946d2a9ca662cb9ccef3f9d45508cd3de58a93542ac2108121
    Port:           8080/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Tue, 19 Mar 2019 14:04:20 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-c9lkr (ro)
Conditions:
  Type           Status
  Initialized    True
  Ready          True
  PodScheduled   True
Volumes:
  default-token-c9lkr:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-c9lkr
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason                 Age   From               Message
  ----    ------                 ----  ----               -------
  Normal  Scheduled              26m   default-scheduler  Successfully assigned kubernetes-bootcamp-85459f8c6c-9jgfl to minikube
  Normal  SuccessfulMountVolume  26m   kubelet, minikube  MountVolume.SetUp succeeded for volume "default-token-c9lkr"
  Normal  Pulled                 26m   kubelet, minikube  Container image "gcr.io/hello-minikube-zero-install/hello-node:latest" already present on machine
  Normal  Created                26m   kubelet, minikube  Created container
  Normal  Started                26m   kubelet, minikube  Started container


# 查看pod日誌
kubectl logs kubernetes-bootcamp-85459f8c6c-9jgfl

# 查看pod環境變量
➜  ~ kubectl exec kubernetes-bootcamp-85459f8c6c-9jgfl env
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=kubernetes-bootcamp-85459f8c6c-9jgfl
KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1
KUBERNETES_SERVICE_HOST=10.96.0.1
KUBERNETES_SERVICE_PORT=443
KUBERNETES_SERVICE_PORT_HTTPS=443
KUBERNETES_PORT=tcp://10.96.0.1:443
KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443
KUBERNETES_PORT_443_TCP_PROTO=tcp
KUBERNETES_PORT_443_TCP_PORT=443
NODE_VERSION=6.14.2
YARN_VERSION=1.6.0
HOME=/root

# 進入pod的shell環境
➜  ~ kubectl exec -it kubernetes-bootcamp-85459f8c6c-9jgfl bash
root@kubernetes-bootcamp-85459f8c6c-9jgfl:/# ls
bin   dev  home  lib64  mnt  proc  run   server.js  sys  usr
boot  etc  lib   media  opt  root  sbin  srv        tmp  var

SERVICES

爲pod/deployment建立serviceapi

# 建立service
➜  minikube kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
service "kubernetes-bootcamp" exposed

# 查看deployment
➜  minikube kubectl get deployments
NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-bootcamp   1         1         1            1           41m

# 查看service
➜  minikube kubectl get services
NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes            ClusterIP   10.96.0.1       <none>        443/TCP          23h
kubernetes-bootcamp   NodePort    10.111.228.62   <none>        8080:32383/TCP   1m

# 查看service相關信息
➜  minikube kubectl describe services/kubernetes-bootcamp
Name:                     kubernetes-bootcamp
Namespace:                default
Labels:                   run=kubernetes-bootcamp
Annotations:              <none>
Selector:                 run=kubernetes-bootcamp
Type:                     NodePort
IP:                       10.111.228.62
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  32383/TCP
Endpoints:                172.17.0.5:8080
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

# 觀察到NodePort，爲Node相關服務暴露的接口，配合node的ip，能夠直接訪問
➜  minikube curl 192.168.99.101:32383
Hello World!%

labels的使用bash

# 使用describe能夠查看到對應的labels
➜  minikube kubectl describe deployment
Name:                   kubernetes-bootcamp
Namespace:              default
CreationTimestamp:      Tue, 19 Mar 2019 14:04:17 +0800
Labels:                 run=kubernetes-bootcamp
Annotations:            deployment.kubernetes.io/revision=1
Selector:               run=kubernetes-bootcamp
Replicas:               1 desired | 1 updated | 1 total | 1 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  1 max unavailable, 1 max surge
Pod Template:
  Labels:  run=kubernetes-bootcamp
  Containers:
   kubernetes-bootcamp:
    Image:        gcr.io/hello-minikube-zero-install/hello-node:latest
    Port:         8080/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Available      True    MinimumReplicasAvailable
  Progressing    True    NewReplicaSetAvailable
OldReplicaSets:  <none>
NewReplicaSet:   kubernetes-bootcamp-85459f8c6c (1/1 replicas created)
Events:
  Type    Reason             Age   From                   Message
  ----    ------             ----  ----                   -------
  Normal  ScalingReplicaSet  44m   deployment-controller  Scaled up replica set kubernetes-bootcamp-85459f8c6c to 1


# 上面labels爲run=kubernetes-bootcamp
# 查看labels對應的pod/service
➜  minikube kubectl get pods -l run=kubernetes-bootcamp
NAME                                   READY     STATUS    RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running   0          47m
➜  minikube kubectl get services -l run=kubernetes-bootcamp
NAME                  TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes-bootcamp   NodePort   10.111.228.62   <none>        8080:32383/TCP   7m

# 爲pod打新label，使用方法相似於docker的tag命令
➜  minikube kubectl label pod kubernetes-bootcamp-85459f8c6c-9jgfl app=v1
pod "kubernetes-bootcamp-85459f8c6c-9jgfl" labeled
➜  minikube kubectl describe pods kubernetes-bootcamp-85459f8c6c-9jgfl
Name:           kubernetes-bootcamp-85459f8c6c-9jgfl
Namespace:      default
Node:           minikube/10.0.2.15
Start Time:     Tue, 19 Mar 2019 14:04:18 +0800
Labels:         app=v1
                pod-template-hash=4101594727
                run=kubernetes-bootcamp

# 查看label對應的pods
➜  minikube kubectl get pods -l app=v1
NAME                                   READY     STATUS    RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running   0          50m

刪除service網絡

# 刪除service，可使用label來刪除
➜  ~ kubectl delete service -l run=kubernetes-bootcamp
service "kubernetes-bootcamp" deleted

# 查看service，能夠看到被刪除
➜  ~ kubectl get services
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   23h

# 服務已經不可用，但pod依然存在
➜  ~ curl 192.168.99.101:32383
curl: (7) Failed to connect to 192.168.99.101 port 32383: Connection refused

➜  ~ kubectl exec -it kubernetes-bootcamp-85459f8c6c-9jgfl bash
root@kubernetes-bootcamp-85459f8c6c-9jgfl:/#

➜  ~ kubectl get pods
NAME                                   READY     STATUS    RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running   0          54m

動態調整

增長/調整分片oracle

# 查看分片
➜  ~ kubectl get deployments
NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-bootcamp   1         1         1            1           1h

# 增長分片
➜  ~ kubectl scale deployments/kubernetes-bootcamp --replicas=3
deployment.extensions "kubernetes-bootcamp" scaled

# 查看效果
➜  ~ kubectl get deployments
NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-bootcamp   3         3         3            3           1h

# 查看各個pod的信息
➜  ~ kubectl get pods -o wide
NAME                                   READY     STATUS    RESTARTS   AGE       IP           NODE
kubernetes-bootcamp-85459f8c6c-4x8fd   1/1       Running   0          1m        172.17.0.6   minikube
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running   0          1h        172.17.0.5   minikube
kubernetes-bootcamp-85459f8c6c-rlzbp   1/1       Running   0          1m        172.17.0.7   minikube

# 使用describe命令能夠查看其變更（包含event）
➜  ~ kubectl describe deployments/kubernetes-bootcamp
Name:                   kubernetes-bootcamp
Namespace:              default
CreationTimestamp:      Tue, 19 Mar 2019 14:04:17 +0800
Labels:                 run=kubernetes-bootcamp
Annotations:            deployment.kubernetes.io/revision=1
Selector:               run=kubernetes-bootcamp
Replicas:               3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  1 max unavailable, 1 max surge
Pod Template:
  Labels:  run=kubernetes-bootcamp
  Containers:
   kubernetes-bootcamp:
    Image:        gcr.io/hello-minikube-zero-install/hello-node:latest
    Port:         8080/TCP
    Host Port:    0/TCP
    Environment:  <none>
    Mounts:       <none>
  Volumes:        <none>
Conditions:
  Type           Status  Reason
  ----           ------  ------
  Progressing    True    NewReplicaSetAvailable
  Available      True    MinimumReplicasAvailable
OldReplicaSets:  <none>
NewReplicaSet:   kubernetes-bootcamp-85459f8c6c (3/3 replicas created)
Events:
  Type    Reason             Age   From                   Message
  ----    ------             ----  ----                   -------
  Normal  ScalingReplicaSet  2m    deployment-controller  Scaled up replica set kubernetes-bootcamp-85459f8c6c to 3


# 暴露services，隨後查看詳細信息
➜  ~ kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
service "kubernetes-bootcamp" exposed

➜  ~ kubectl get services
NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes            ClusterIP   10.96.0.1       <none>        443/TCP          1d
kubernetes-bootcamp   NodePort    10.97.170.139   <none>        8080:30424/TCP   6s

➜  ~ kubectl describe services/kubernetes-bootcamp
Name:                     kubernetes-bootcamp
Namespace:                default
Labels:                   run=kubernetes-bootcamp
Annotations:              <none>
Selector:                 run=kubernetes-bootcamp
Type:                     NodePort
IP:                       10.97.170.139
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30424/TCP
Endpoints:                172.17.0.5:8080,172.17.0.6:8080,172.17.0.7:8080
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

# 驗證服務
➜  ~ curl 192.168.99.101:30424
Hello World!%

# 能夠從新調整分片
➜  ~ kubectl scale deployments/kubernetes-bootcamp --replicas=2
deployment.extensions "kubernetes-bootcamp" scaled

➜  ~ kubectl get deployments
NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-bootcamp   2         2         2            2           1h

# 能夠查看到變化
➜  ~ kubectl get pods -o wide
NAME                                   READY     STATUS        RESTARTS   AGE       IP           NODE
kubernetes-bootcamp-85459f8c6c-4x8fd   1/1       Running       0          7m        172.17.0.6   minikube
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running       0          1h        172.17.0.5   minikube
kubernetes-bootcamp-85459f8c6c-rlzbp   1/1       Terminating   0          7m        172.17.0.7   minikube

➜  ~ kubectl get pods
NAME                                   READY     STATUS        RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-4x8fd   1/1       Running       0          7m
kubernetes-bootcamp-85459f8c6c-9jgfl   1/1       Running       0          1h
kubernetes-bootcamp-85459f8c6c-rlzbp   1/1       Terminating   0          7m

更新服務

# 更新爲新的鏡像（首先須要導入新的鏡像，新鏡像返回的內容從hello world變動爲hello）
➜  minikube kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=node_hello:2
deployment.apps "kubernetes-bootcamp" image updated

# 查看pods，能夠看到過程
➜  minikube kubectl get pods
NAME                                   READY     STATUS        RESTARTS   AGE
kubernetes-bootcamp-85459f8c6c-4x8fd   1/1       Terminating   1          1h
kubernetes-bootcamp-b4d449bd-vlnpd     1/1       Running       0          17m

# services沒有發生變化
➜  minikube kubectl get services
NAME                  TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes            ClusterIP   10.96.0.1       <none>        443/TCP          1d
kubernetes-bootcamp   NodePort    10.97.170.139   <none>        8080:30424/TCP   1h

# describe能夠看到鏡像已經發生變化
➜  minikube kubectl describe pod kubernetes-bootcamp-b4d449bd-vlnpd
Name:           kubernetes-bootcamp-b4d449bd-vlnpd
Namespace:      default
Node:           minikube/10.0.2.15
Start Time:     Tue, 19 Mar 2019 16:07:19 +0800
Labels:         pod-template-hash=60800568
                run=kubernetes-bootcamp
Annotations:    <none>
Status:         Running
IP:             172.17.0.5
Controlled By:  ReplicaSet/kubernetes-bootcamp-b4d449bd
Containers:
  kubernetes-bootcamp:
    Container ID:   docker://fb59d3c98a1ca705640520954198d5bb336167a8fe1e40603e9281e714a997f4
    Image:          node_hello:2
    Image ID:       docker://sha256:74a687422f4cb90ac252a35b6e0bef78d5f4a546fa64b63afc672b763ce5e6b2
    Port:           8080/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Tue, 19 Mar 2019 16:07:20 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-c9lkr (ro)
Conditions:
  Type           Status
  Initialized    True
  Ready          True
  PodScheduled   True
Volumes:
  default-token-c9lkr:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-c9lkr
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason                 Age   From               Message
  ----    ------                 ----  ----               -------
  Normal  Scheduled              17m   default-scheduler  Successfully assigned kubernetes-bootcamp-b4d449bd-vlnpd to minikube
  Normal  SuccessfulMountVolume  17m   kubelet, minikube  MountVolume.SetUp succeeded for volume "default-token-c9lkr"
  Normal  Pulled                 17m   kubelet, minikube  Container image "node_hello:2" already present on machine
  Normal  Created                17m   kubelet, minikube  Created container
  Normal  Started                17m   kubelet, minikube  Started container

從上面能夠看到服務已經更新，可使用下面的方式驗證一下app

# 經過describe查看service的nodeport
➜  ~ kubectl describe service kubernetes-bootcamp
Name:                     kubernetes-bootcamp
Namespace:                default
Labels:                   run=kubernetes-bootcamp
Annotations:              <none>
Selector:                 run=kubernetes-bootcamp
Type:                     NodePort
IP:                       10.97.170.139
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30424/TCP
Endpoints:                172.17.0.5:8080
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>


# 返回內容已經變動爲hello（以前爲hello world）
➜  minikube curl 192.168.99.101:30424
Hello%

# 也能夠經過下面命令來驗證更新結果
➜  ~ kubectl rollout status deployments/kubernetes-bootcamp
deployment "kubernetes-bootcamp" successfully rolled out