目录：（可以按w快捷键切换大纲视图）
POD创建时指定工作节点主机host上一个dir分配给POD
# cat cpu-ram-rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: cpu-ram-demo
spec:
replicas: 1
selector:
name: cpu-ram-demo
template:
metadata:
labels:
name: cpu-ram-demo
spec:
containers:
- name: cpu-ram-demo-container
image: registry.paas/library/nginx:1.15.9
resources:
requests:
memory: "200Mi"
cpu: "2"
limits:
memory: "200Mi"
cpu: "2"
volumeMounts:
- mountPath: /etc/work
name: host5490
volumes:
- hostPath:
path: /docker_temp
name: host5490
# kubectl create -f cpu-ram-rc.yaml
replicationcontroller/cpu-ram-demo created
# kubectl get pod|grep cpu-ram-demo
cpu-ram-demo-qmxf4 1/1 Running 0 48s
# kubectl exec -it cpu-ram-demo-qmxf4 bash
root@cpu-ram-demo-qmxf4:/# cd /etc/work/
root@cpu-ram-demo-qmxf4:/etc/work# ls
root@cpu-ram-demo-qmxf4:/etc/work#
# cd /docker_temp/
# ls
#
在容器中对应的目录新建文件`from_docker`，在host上对应的目录可以查看到；在host对应的目录创建`from_host`，在容器对应的目录可以查看到。
root@cpu-ram-demo-qmxf4:/etc/work# touch from_docker
root@cpu-ram-demo-qmxf4:/etc/work# ls
from_docker
root@cpu-ram-demo-qmxf4:/etc/work#
# ls
from_docker
# touch from_host
# ls
from_docker from_host
#
root@cpu-ram-demo-qmxf4:/etc/work# ls
from_docker from_host
root@cpu-ram-demo-qmxf4:/etc/work#
若出现故障，POD重生到其他的工作节点POD原挂载到目录里的内容会丢失。
POD创建时配置存储卷类型为emptyDir
# cat cpu-ram-rc-emptydir.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: cpu-ram-demo
spec:
replicas: 1
selector:
name: cpu-ram-demo
template:
metadata:
labels:
name: cpu-ram-demo
spec:
containers:
- name: cpu-ram-demo-container
image: registry.paas/library/nginx:1.15.9
resources:
requests:
memory: "200Mi"
cpu: "2"
limits:
memory: "200Mi"
cpu: "2"
volumeMounts:
- mountPath: /etc/work
name: host5490
volumes:
- name: host5490
emptyDir: {}
# kubectl create -f cpu-ram-rc-emptydir.yaml
replicationcontroller/cpu-ram-demo created
# kubectl get pod|grep cpu-ram
cpu-ram-demo-h8cwf 1/1 Running 0 32s
# kubectl describe pod cpu-ram-demo-h8cwf
Name: cpu-ram-demo-h8cwf
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: paasn4/39.135.102.125
Start Time: Wed, 27 May 2020 21:08:57 +0800
Labels: name=cpu-ram-demo
Annotations: <none>
Status: Running
IP: 10.222.90.218
Controlled By: ReplicationController/cpu-ram-demo
Containers:
cpu-ram-demo-container:
Container ID: docker://0ffc339f7961b71c5db778cbbe7f738c78fdd5b57013e2b43a3ab2d488f463f7
Image: registry.paas/library/nginx:1.15.9
Image ID: docker-pullable://registry.paas/library/nginx@sha256:082b7224e857035c61eb4a802bfccf8392736953f78a99096acc7e3296739889
Port: <none>
Host Port: <none>
State: Running
Started: Wed, 27 May 2020 21:08:59 +0800
Ready: True
Restart Count: 0
Limits:
cpu: 2
memory: 200Mi
Requests:
cpu: 2
memory: 200Mi
Environment: <none>
Mounts:
/etc/work from host5490 (rw)
/var/run/secrets/kubernetes.io/serviceaccount from default-token-vc2bx (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
host5490:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
Medium:
default-token-vc2bx:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-vc2bx
Optional: false
QoS Class: Guaranteed
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 68s default-scheduler Successfully assigned default/cpu-ram-demo-h8cwf to paasn4
Normal Pulled <invalid> kubelet, paasn4 Container image "registry.paas/library/nginx:1.15.9" already present on machine
Normal Created <invalid> kubelet, paasn4 Created container
Normal Started <invalid> kubelet, paasn4 Started container
若出现故障，POD重生到其他的工作节点POD原挂载到目录里的内容会丢失。
POD创建时配置sercret
# echo -n "1f2d1e2e67df" > ./password.txt
# kubectl create secret generic db-user-pass --from-file=./password.txt
secret/db-user-pass created
# cat cpu-ram-rc-secret.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: cpu-ram-demo
spec:
replicas: 1
selector:
name: cpu-ram-demo
template:
metadata:
labels:
name: cpu-ram-demo
spec:
containers:
- name: cpu-ram-demo-container
image: registry.paas/library/nginx:1.15.9
resources:
requests:
memory: "200Mi"
cpu: "2"
limits:
memory: "200Mi"
cpu: "2"
volumeMounts:
- name: foo
mountPath: /etc/foo
readOnly: true
volumes:
- name: foo
secret:
secretName: db-user-pass
# kubectl create -f cpu-ram-rc-secret.yaml
replicationcontroller/cpu-ram-demo created
# kubectl get pod|grep cpu-ram
cpu-ram-demo-bdnpz 1/1 Running 0 27s
# kubectl exec -it cpu-ram-demo-bdnpz bash
root@cpu-ram-demo-bdnpz:/# cd /etc/foo/
root@cpu-ram-demo-bdnpz:/etc/foo# ls
password.txt
root@cpu-ram-demo-bdnpz:/etc/foo# cat password.txt
1f2d1e2e67dfroot@cpu-ram-demo-bdnpz:/etc/foo#
若出现故障，POD重生到其他的工作节点POD目录里的password.txt内容不会丢失。
POD创建时配置configmap
# kubectl create configmap special-config --from-literal=special.how=very
configmap/special-config created
# cat cpu-ram-rc-configmap.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: cpu-ram-demo
spec:
replicas: 1
selector:
name: cpu-ram-demo
template:
metadata:
labels:
name: cpu-ram-demo
spec:
containers:
- name: cpu-ram-demo-container
image: registry.paas/library/nginx:1.15.9
env:
- name: SPECIAL_LEVEL_KEY
valueFrom:
configMapKeyRef:
name: special-config
key: special.how
resources:
requests:
memory: "200Mi"
cpu: "2"
limits:
memory: "200Mi"
cpu: "2"
# kubectl create -f cpu-ram-rc-configmap.yaml
replicationcontroller/cpu-ram-demo created
# kubectl get pod|grep cpu-ram
cpu-ram-demo-lhwlc 1/1 Running 0 36s
# kubectl exec -it cpu-ram-demo-lhwlc bash
root@cpu-ram-demo-lhwlc:/# env|grep very
SPECIAL_LEVEL_KEY=very
root@cpu-ram-demo-lhwlc:/#
若出现故障，POD重生到其他的工作节点POD环境变量env的SPECIAL_LEVEL_KEY=very不会丢失。
pod自动扩缩容
创建deployment nginx-test和service nginx-test，service暴露端口80
# kubectl run nginx-test --image=registry.paas/library/nginx:1.15.9 --requests=cpu=20m --expose --port=80
kubectl run --generator=deployment/apps.v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create instead.
service/nginx-test created
deployment.apps/nginx-test created
创建hpa（horizontalpodautoscaler），pod数量从1~10，一旦cpu占有率超过5%。就自动进行扩容，若cpu低于5%，就自动进行缩容
[root@paasm1 ~]# kubectl autoscale deployment nginx-test --cpu-percent=5 --min=1 --max=10
horizontalpodautoscaler.autoscaling/nginx-test autoscaled
[root@paasm1 ~]# kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.233.0.1 <none> 443/TCP 26d
nginx-test ClusterIP 10.233.28.40 <none> 80/TCP 23s
加压前
# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
nginx-test Deployment/nginx-test 0%/5% 1 10 1 104s
登陆到集群任意一节点对nginx-service进行加压操作
# while true;do curl 10.233.28.40 >/dev/null 2>&1;done
加压一段时候后，pod数量从1变成10
# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
nginx-test Deployment/nginx-test 14%/5% 1 10 10 5m28s
# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-test-7745fc4958-94msx 1/1 Running 0 3m59s
nginx-test-7745fc4958-9fvzj 1/1 Running 0 3m43s
nginx-test-7745fc4958-bfzqt 1/1 Running 0 3m59s
nginx-test-7745fc4958-bp2hf 1/1 Running 0 4m14s
nginx-test-7745fc4958-ff7sm 1/1 Running 0 3m59s
nginx-test-7745fc4958-fsdq5 1/1 Running 0 3m59s
nginx-test-7745fc4958-mtwkb 1/1 Running 0 3m43s
nginx-test-7745fc4958-n9kgc 1/1 Running 0 6m13s
nginx-test-7745fc4958-pzwlg 1/1 Running 0 4m14s
nginx-test-7745fc4958-x5sw9 1/1 Running 0 4m14s
停止加压操作，pod数量从10变成1
# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
nginx-test Deployment/nginx-test 0%/5% 1 10 1 12m
# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-test-7745fc4958-n9kgc 1/1 Running 0 22m
升级和回滚
# cat pod-30.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-test
# annotations:
# io.kubernetes.cri.untrusted-workload: "true"
spec:
replicas: 30
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: registry.paas/library/nginx:1.13
创建deployments/nginx-test，有30个pod，nginx的版本是1.13
# kubectl create -f pod-30.yaml
deployment.extensions/nginx-test created
# kubectl get deployment nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 0/30 30 0 5s
创建中......
# kubectl get deployment nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 7/30 30 7 9s
创建完成
# kubectl get deployment nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 30/30 30 30 19s
# kubectl get pod|grep nginx-test
nginx-test-c6fcf8b85-2mhk8 1/1 Running 0 43s
nginx-test-c6fcf8b85-4c62c 1/1 Running 0 43s
nginx-test-c6fcf8b85-6kx9p 1/1 Running 0 43s
nginx-test-c6fcf8b85-78nc6 1/1 Running 0 43s
nginx-test-c6fcf8b85-79vfr 1/1 Running 0 43s
nginx-test-c6fcf8b85-8l7dc 1/1 Running 0 43s
nginx-test-c6fcf8b85-9n7dh 1/1 Running 0 43s
nginx-test-c6fcf8b85-bcpj9 1/1 Running 0 43s
nginx-test-c6fcf8b85-c9p4h 1/1 Running 0 43s
nginx-test-c6fcf8b85-dp8rg 1/1 Running 0 43s
nginx-test-c6fcf8b85-dsll8 1/1 Running 0 43s
nginx-test-c6fcf8b85-fqcpb 1/1 Running 0 43s
nginx-test-c6fcf8b85-fsh8h 1/1 Running 0 43s
nginx-test-c6fcf8b85-h6v5l 1/1 Running 0 43s
nginx-test-c6fcf8b85-jmtjr 1/1 Running 0 43s
nginx-test-c6fcf8b85-krpj9 1/1 Running 0 43s
nginx-test-c6fcf8b85-lhdf7 1/1 Running 0 43s
nginx-test-c6fcf8b85-lqzgj 1/1 Running 0 43s
nginx-test-c6fcf8b85-m6kfp 1/1 Running 0 43s
nginx-test-c6fcf8b85-n8ccf 1/1 Running 0 43s
nginx-test-c6fcf8b85-r4wrb 1/1 Running 0 43s
nginx-test-c6fcf8b85-r72qk 1/1 Running 0 43s
nginx-test-c6fcf8b85-rrd7l 1/1 Running 0 43s
nginx-test-c6fcf8b85-shvmg 1/1 Running 0 43s
nginx-test-c6fcf8b85-tdhz7 1/1 Running 0 43s
nginx-test-c6fcf8b85-tlqcv 1/1 Running 0 43s
nginx-test-c6fcf8b85-vkrf5 1/1 Running 0 43s
nginx-test-c6fcf8b85-vwdtc 1/1 Running 0 43s
nginx-test-c6fcf8b85-wdwcc 1/1 Running 0 43s
nginx-test-c6fcf8b85-zf4nv 1/1 Running 0 43s
# kubectl describe deployment nginx-test
Name: nginx-test
Namespace: default
CreationTimestamp: Tue, 09 Jun 2020 17:35:32 +0800
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision: 1
Selector: app=nginx
Replicas: 30 desired | 30 updated | 30 total | 30 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: registry.paas/library/nginx:1.13
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-test-c6fcf8b85 (30/30 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 61s deployment-controller Scaled up replica set nginx-test-c6fcf8b85 to 30
执行升级命令
# kubectl set image deployments nginx-test nginx=registry.paas/library/nginx:1.15.9
deployment.extensions/nginx-test image updated
升级中......
# kubectl get deployments/nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 29/30 24 29 2m4s
升级完成，30个pod的nginx版本都升级到1.15.9
# kubectl get deployments/nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 30/30 30 30 2m25s
# kubectl describe deployment nginx-test
Name: nginx-test
Namespace: default
CreationTimestamp: Tue, 09 Jun 2020 17:35:32 +0800
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision: 2
Selector: app=nginx
Replicas: 30 desired | 30 updated | 30 total | 30 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: registry.paas/library/nginx:1.15.9
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-test-6db76bdf4d (30/30 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 2m20s deployment-controller Scaled up replica set nginx-test-c6fcf8b85 to 30
Normal ScalingReplicaSet 48s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 1
Normal ScalingReplicaSet 48s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 29
Normal ScalingReplicaSet 48s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 2
Normal ScalingReplicaSet 47s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 28
Normal ScalingReplicaSet 47s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 3
Normal ScalingReplicaSet 46s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 27
Normal ScalingReplicaSet 46s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 4
Normal ScalingReplicaSet 44s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 26
Normal ScalingReplicaSet 35s (x16 over 44s) deployment-controller (combined from similar events): Scaled down replica set nginx-test-c6fcf8b85 to 18
执行回滚操作
# kubectl rollout undo deployments nginx-test
deployment.extensions/nginx-test rolled back
回滚中......
# kubectl get deployments/nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 29/30 14 29 3m53s
# kubectl describe deployment nginx-test
Name: nginx-test
Namespace: default
CreationTimestamp: Tue, 09 Jun 2020 17:35:32 +0800
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision: 3
Selector: app=nginx
Replicas: 30 desired | 15 updated | 31 total | 29 available | 2 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: registry.paas/library/nginx:1.13
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: nginx-test-6db76bdf4d (15/15 replicas created)
NewReplicaSet: nginx-test-c6fcf8b85 (16/16 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 3m56s deployment-controller Scaled up replica set nginx-test-c6fcf8b85 to 30
Normal ScalingReplicaSet 2m24s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 1
Normal ScalingReplicaSet 2m24s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 29
Normal ScalingReplicaSet 2m24s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 2
Normal ScalingReplicaSet 2m23s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 28
Normal ScalingReplicaSet 2m23s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 3
Normal ScalingReplicaSet 2m22s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 27
Normal ScalingReplicaSet 2m22s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 4
Normal ScalingReplicaSet 2m20s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 26
Normal ScalingReplicaSet 2m11s (x16 over 2m20s) deployment-controller (combined from similar events): Scaled down replica set nginx-test-c6fcf8b85 to 18
回滚完成，30个pod的nginx版本都回滚到1.13
# kubectl get deployments/nginx-test
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-test 30/30 30 30 4m35s
# kubectl describe deployment nginx-test
Name: nginx-test
Namespace: default
CreationTimestamp: Tue, 09 Jun 2020 17:35:32 +0800
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision: 3
Selector: app=nginx
Replicas: 30 desired | 30 updated | 30 total | 30 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: registry.paas/library/nginx:1.13
Port: <none>
Host Port: <none>
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: nginx-test-c6fcf8b85 (30/30 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 4m37s deployment-controller Scaled up replica set nginx-test-c6fcf8b85 to 30
Normal ScalingReplicaSet 3m5s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 1
Normal ScalingReplicaSet 3m5s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 29
Normal ScalingReplicaSet 3m5s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 2
Normal ScalingReplicaSet 3m4s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 28
Normal ScalingReplicaSet 3m4s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 3
Normal ScalingReplicaSet 3m3s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 27
Normal ScalingReplicaSet 3m3s deployment-controller Scaled up replica set nginx-test-6db76bdf4d to 4
Normal ScalingReplicaSet 3m1s deployment-controller Scaled down replica set nginx-test-c6fcf8b85 to 26
Normal ScalingReplicaSet 2m52s (x16 over 3m1s) deployment-controller (combined from similar events): Scaled down replica set nginx-test-c6fcf8b85 to 18
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