昨天我們已經把k8s的集群在AWS上架設起來了，今天我們稍微操作下基礎篇的內容，看看會有什麼差異，值得一提的是，我們在昨天新增了三個Node，這三個Node是計算節點，主節點Master的部分是EKS在管理的，我們不能去操控它，並且它自帶HA（High Availability），高可用性，也就是有主節點的備援，我們不需要再集群內新增主節點並設置HA，HA的好處是當主節點掛掉的時候，它會用另外兩個備用的選一個當作新的主節點，並會找一個新的主備用節點，維持同時三個主節點的狀態。k8s在使用上是基於etcd的，它是一個時間序列的資料庫，因此備援系統的設置顯得格外重要，它可以保證群集資料的完整性。
接著我們應用前面所學的知識，操作基礎篇的內容
在開始之前，我們先確定版本
$kubectl version --short
Client Version: v1.13.11-eks-5876d6
Server Version: v1.13.10-eks-5ac0f1
我們前面有提過標籤（Label）、活性（livenessProbe）、可讀性（readinessProbe）
在這邊我們綜合運用一下
$vim pod-demo.yaml
apiVersion: v1
kind: Pod
metadata:
name: my-helloworld
labels:
app: helloworld
spec:
containers:
- name: k8s-demo
image: 105552010/k8s-demo
args:
- /bin/sh
- -c
- touch /tmp/healthy; npm start; sleep 30; rm -rf /tmp/healthy; sleep 600
ports:
- name: nodejs-port
containerPort: 3000
livenessProbe:
httpGet:
path: /
port: 3000
initialDelaySeconds: 15
timeoutSeconds: 30
readinessProbe:
exec:
command:
- cat
- /tmp/healthy
initialDelaySeconds: 5
periodSeconds: 5
接著apply它並檢查Pod狀態
$kubectl apply -f pod-demo.yaml
pod/my-helloworld created
$kubectl get po
NAME READY STATUS RESTARTS AGE
my-helloworld 1/1 Running 0 20s
詳細檢查，可以發現到不一樣
$kubectl describe po
Name: my-helloworld
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: ip-192-168-18-184.ap-southeast-1.compute.internal/192.168.18.184
Start Time: Mon, 07 Oct 2019 16:09:42 +0800
Labels: app=helloworld
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"labels":{"app":"helloworld"},"name":"my-helloworld","namespace":"default"}
kubernetes.io/psp: eks.privileged
Status: Running
IP: 192.168.28.191
Containers:
k8s-demo:
Container ID: docker://ea5c9229dd6589a136dfd72aafa63333081f4e31403a16325634f27517f359bc
Image: 105552010/k8s-demo
Image ID: docker-pullable://105552010/k8s-demo@sha256:2c050f462f5d0b3a6430e7869bcdfe6ac48a447a89da79a56d0ef61460c7ab9e
Port: 3000/TCP
Host Port: 0/TCP
Args:
/bin/sh
-c
touch /tmp/healthy; npm start; sleep 30; rm -rf /tmp/healthy; sleep 600
State: Running
Started: Mon, 07 Oct 2019 16:09:46 +0800
Ready: True
Restart Count: 0
Liveness: http-get http://:3000/ delay=15s timeout=30s period=10s #success=1 #failure=3
Readiness: exec [cat /tmp/healthy] delay=5s timeout=1s period=5s #success=1 #failure=3
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-b6shs (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-b6shs:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-b6shs
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 2m25s default-scheduler Successfully assigned default/my-helloworld to ip-192-168-18-184.ap-southeast-1.compute.internal
Normal Pulling 2m24s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal pulling image "105552010/k8s-demo"
Normal Pulled 2m21s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Successfully pulled image "105552010/k8s-demo"
Normal Created 2m21s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Created container
Normal Started 2m21s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Started container
節點等訊息可以看出與minikube的差異
恢復原狀
$kubectl delete -f pod-demo.yaml
pod "my-helloworld" deleted
接著我們看下一個例子
前面有提過Scaling的部分包含Horizontal和Vertical
我們看個例子，用ReplicationController測試
$vim pod-scale.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: helloworld-controller
spec:
replicas: 2
selector:
app: helloworld
template:
metadata:
labels:
app: helloworld
spec:
containers:
- name: k8s-demo
image: 105552010/k8s-demo
ports:
- containerPort: 3000
resources:
requests:
cpu: 100m
memory: 50Mi
接著一樣apply，很熟悉吧？
$kubectl apply -f pod-scale.yaml
replicationcontroller/helloworld-controller created
檢查Pod狀態
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-controller-9gb5m 0/1 ContainerCreating 0 20s
helloworld-controller-bz9t2 1/1 Running 0 20s
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-controller-9gb5m 1/1 Running 0 23s
helloworld-controller-bz9t2 1/1 Running 0 23s
詳細檢查Pod狀態
$kubectl describe po
Name: helloworld-controller-9gb5m
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: ip-192-168-51-244.ap-southeast-1.compute.internal/192.168.51.244
Start Time: Mon, 07 Oct 2019 16:44:51 +0800
Labels: app=helloworld
Annotations: kubernetes.io/psp: eks.privileged
Status: Running
IP: 192.168.54.6
Controlled By: ReplicationController/helloworld-controller
Containers:
k8s-demo:
Container ID: docker://0292d73e55d870d549d31fe2f54320d3ad4af49d3d04aad42f0e6f7a0d729de7
Image: 105552010/k8s-demo
Image ID: docker-pullable://105552010/k8s-demo@sha256:2c050f462f5d0b3a6430e7869bcdfe6ac48a447a89da79a56d0ef61460c7ab9e
Port: 3000/TCP
Host Port: 0/TCP
State: Running
Started: Mon, 07 Oct 2019 16:45:11 +0800
Ready: True
Restart Count: 0
Requests:
cpu: 100m
memory: 50Mi
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-b6shs (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-b6shs:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-b6shs
Optional: false
QoS Class: Burstable
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 73s default-scheduler Successfully assigned default/helloworld-controller-9gb5m to ip-192-168-51-244.ap-southeast-1.compute.internal
Normal Pulling 72s kubelet, ip-192-168-51-244.ap-southeast-1.compute.internal pulling image "105552010/k8s-demo"
Normal Pulled 58s kubelet, ip-192-168-51-244.ap-southeast-1.compute.internal Successfully pulled image "105552010/k8s-demo"
Normal Created 53s kubelet, ip-192-168-51-244.ap-southeast-1.compute.internal Created container
Normal Started 53s kubelet, ip-192-168-51-244.ap-southeast-1.compute.internal Started container
Name: helloworld-controller-bz9t2
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: ip-192-168-18-184.ap-southeast-1.compute.internal/192.168.18.184
Start Time: Mon, 07 Oct 2019 16:44:51 +0800
Labels: app=helloworld
Annotations: kubernetes.io/psp: eks.privileged
Status: Running
IP: 192.168.14.232
Controlled By: ReplicationController/helloworld-controller
Containers:
k8s-demo:
Container ID: docker://4c5434332b92fef28fbdbffa69738ad13f7a960d42c5ea147262b55fbf923e8b
Image: 105552010/k8s-demo
Image ID: docker-pullable://105552010/k8s-demo@sha256:2c050f462f5d0b3a6430e7869bcdfe6ac48a447a89da79a56d0ef61460c7ab9e
Port: 3000/TCP
Host Port: 0/TCP
State: Running
Started: Mon, 07 Oct 2019 16:44:55 +0800
Ready: True
Restart Count: 0
Requests:
cpu: 100m
memory: 50Mi
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-b6shs (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-b6shs:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-b6shs
Optional: false
QoS Class: Burstable
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 73s default-scheduler Successfully assigned default/helloworld-controller-bz9t2 to ip-192-168-18-184.ap-southeast-1.compute.internal
Normal Pulling 72s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal pulling image "105552010/k8s-demo"
Normal Pulled 69s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Successfully pulled image "105552010/k8s-demo"
Normal Created 69s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Created container
Normal Started 69s kubelet, ip-192-168-18-184.ap-southeast-1.compute.internal Started container
可以注意到它把Pod開在兩個不同的EC2的instance上
恢復原狀
$kubectl delete -f pod-scale.yaml
replicationcontroller "helloworld-controller" deleted
當然，我們也知道這可以用Deployment的ReplicaSet代替
$vim pod-deploy.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: helloworld-deployment
spec:
replicas: 2
template:
metadata:
labels:
app: helloworld
spec:
containers:
- name: k8s-demo
image: 105552010/k8s-demo
ports:
- containerPort: 3000
resources:
requests:
cpu: 100m
memory: 50Mi
接著建立它
$kubectl create -f pod-deploy.yaml
deployment.extensions/helloworld-deployment created
檢查狀態，這個Deployment開啟了2個Pod，每個Pod的要求資源是cpu：100m、memory：50Mi
$kubectl get deployment
NAME READY UP-TO-DATE AVAILABLE AGE
helloworld-deployment 2/2 2 2 3m55s
$kubectl describe deploy
Name: helloworld-deployment
Namespace: default
CreationTimestamp: Mon, 07 Oct 2019 17:02:09 +0800
Labels: app=helloworld
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=helloworld
Replicas: 2 desired | 2 updated | 2 total | 2 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=helloworld
Containers:
k8s-demo:
Image: 105552010/k8s-demo
Port: 3000/TCP
Host Port: 0/TCP
Requests:
cpu: 100m
memory: 50Mi
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: helloworld-deployment-5b5457694d (2/2 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 4m6s deployment-controller Scaled up replica set helloworld-deployment-5b5457694d to 2
我們接著測試一些東西：
將deployment設成Pause狀態
$kubectl rollout pause deployment/helloworld-deployment
deployment.extensions/helloworld-deployment paused
修改Deployment可使用的資源
$kubectl set resources deployment helloworld-deployment --limits=cpu=200m,memory=100Mi
deployment.extensions/helloworld-deployment resource requirements updated
更新所用的image版本
$kubectl set image deployment/helloworld-deployment k8s-demo=105552010/k8s-demo:v2
deployment.extensions/helloworld-deployment image updated
回復正常狀態
$kubectl rollout resume deploy/helloworld-deployment
deployment.extensions/helloworld-deployment resumed
檢查Pod狀態
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-5b5457694d-hbw78 1/1 Running 0 12m
helloworld-deployment-5b5457694d-v95bg 1/1 Terminating 0 12m
helloworld-deployment-9d595467-s4z9p 0/1 ContainerCreating 0 6s
helloworld-deployment-9d595467-s7wfx 0/1 ContainerCreating 0 6s
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-5b5457694d-hbw78 0/1 Terminating 0 13m
helloworld-deployment-9d595467-s4z9p 1/1 Running 0 40s
helloworld-deployment-9d595467-s7wfx 1/1 Running 0 40s
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-9d595467-s4z9p 1/1 Running 0 64s
helloworld-deployment-9d595467-s7wfx 1/1 Running 0 64s
檢查Image版本
$kubectl describe deployment|grep -i image
Image: 105552010/k8s-demo:v2
創造更多分身（從2改成3）
$kubectl scale deployment/helloworld-deployment --replicas=3
deployment.extensions/helloworld-deployment scaled
檢查Pod狀態
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-9d595467-dkxg4 0/1 ContainerCreating 0 19s
helloworld-deployment-9d595467-s4z9p 1/1 Running 0 5m32s
helloworld-deployment-9d595467-s7wfx 1/1 Running 0 5m32s
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-9d595467-dkxg4 1/1 Running 0 56s
helloworld-deployment-9d595467-s4z9p 1/1 Running 0 6m9s
helloworld-deployment-9d595467-s7wfx 1/1 Running 0 6m9s
我們也可以設置AutoScaling
這邊是說最小4個Pod，最多10個，當cpu的loading大於80%就開始增加Pod，後面會詳細介紹
$kubectl autoscale deployment/helloworld-deployment --min=4 --max=10 --cpu-percent=80
horizontalpodautoscaler.autoscaling/helloworld-deployment autoscaled
檢查Pod狀態，最小是4，所以至少要4個
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-9d595467-dkxg4 1/1 Running 0 3m52s
helloworld-deployment-9d595467-phvvr 1/1 Running 0 76s
helloworld-deployment-9d595467-s4z9p 1/1 Running 0 9m5s
helloworld-deployment-9d595467-s7wfx 1/1 Running 0 9m5s
檢查更新狀態
$kubectl rollout status deployment/helloworld-deployment
deployment "helloworld-deployment" successfully rolled out
檢查詳細記錄
$kubectl describe deployment
Name: helloworld-deployment
Namespace: default
CreationTimestamp: Mon, 07 Oct 2019 17:02:09 +0800
Labels: app=helloworld
Annotations: deployment.kubernetes.io/revision: 2
Selector: app=helloworld
Replicas: 4 desired | 4 updated | 4 total | 4 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=helloworld
Containers:
k8s-demo:
Image: 105552010/k8s-demo:v2
Port: 3000/TCP
Host Port: 0/TCP
Limits:
cpu: 200m
memory: 100Mi
Requests:
cpu: 100m
memory: 50Mi
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: helloworld-deployment-9d595467 (4/4 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 24m deployment-controller Scaled up replica set helloworld-deployment-5b5457694d to 2
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set helloworld-deployment-9d595467 to 1
Normal ScalingReplicaSet 11m deployment-controller Scaled down replica set helloworld-deployment-5b5457694d to 1
Normal ScalingReplicaSet 11m deployment-controller Scaled up replica set helloworld-deployment-9d595467 to 2
Normal ScalingReplicaSet 11m deployment-controller Scaled down replica set helloworld-deployment-5b5457694d to 0
Normal ScalingReplicaSet 6m14s deployment-controller Scaled up replica set helloworld-deployment-9d595467 to 3
Normal ScalingReplicaSet 3m38s deployment-controller Scaled up replica set helloworld-deployment-9d595467 to 4
將現有版本回朔到上一個版本。還記得瑪莎多拉嗎？
$kubectl rollout undo deployment/helloworld-deployment
deployment.extensions/helloworld-deployment rolled back
檢查倒回狀態
$kubectl rollout status deployment/helloworld-deployment
deployment "helloworld-deployment" successfully rolled out
檢查Image版本
$kubectl describe deployment|grep -i image
Image: 105552010/k8s-demo
檢查Pod狀態，應該沒變，只是改Image的版本而已
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-5b5457694d-6p7pl 1/1 Running 0 75s
helloworld-deployment-5b5457694d-ghhxw 1/1 Running 0 75s
helloworld-deployment-5b5457694d-lfckb 1/1 Running 0 70s
helloworld-deployment-5b5457694d-lgl7h 1/1 Running 0 71s
檢查rolling的紀錄
$kubectl rollout history deployment/helloworld-deployment
deployment.extensions/helloworld-deployment
REVISION CHANGE-CAUSE
2 <none>
3 <none>
最後恢復原狀
$kubectl delete -f pod-deploy.yaml
deployment.extensions "helloworld-deployment" deleted
Pod也會一併刪除
$kubectl get po
NAME READY STATUS RESTARTS AGE
helloworld-deployment-5b5457694d-6p7pl 1/1 Terminating 0 5m43s
helloworld-deployment-5b5457694d-ghhxw 1/1 Terminating 0 5m43s
helloworld-deployment-5b5457694d-lfckb 1/1 Terminating 0 5m38s
helloworld-deployment-5b5457694d-lgl7h 1/1 Terminating 0 5m39s
$kubectl get po
No resources found.
OK，基礎篇的AWS操作就到這邊囉～
今天我們看到了在基礎篇整個運用在AWS上的樣子，基本上大同小異，只是會噴錢而已（笑，不過因為是遠端的連線，所以有時候會稍微卡一下，大致上使用還算是蠻順暢的，目前已經把之前基礎篇的部分大致瀏覽過，算是個完整的複習，當然我們也有看到新的部分，像是Scale up和Auto Scaling的部分，下一篇將會介紹進階篇的一些操作，我們明天見～
本文同步刊載於https://github.com/x1y2z3456/ironman
感謝您撥冗閱讀此文章，不喜勿噴，有任何問題建議歡迎下方留言：）
說個笑話，希望我能寫滿30天啊（笑
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