k8s部署一个带有mysql应用_k8s(Kubernetes)快速部署捷径(6)-集群mysql应用实例-Go语言中文社区...

六、应用实例

6.1 创建MySQL实例

6.1.1 定义描述文件

apiVersion: v1

kind: ReplicationController #副本控制器RC

metadata:

name: mysql #RC的名称，全局唯一

spec:

replicas: 1 #Pod副本的期待数量

selector:

app: mysql #符合目标的Pod拥有此标签

template: #根据此模板创建Pod的副本(实例)

metadata:

labels:

app: mysql #Pod副本拥有的标签，对应RC的Selector

spec:

containers: #Pod内容器的定义部分

- name: mysql #容器的名称

image: hub.c.163.com/library/mysql #容器对应的Docker image

ports:

- containerPort: 3306 #容器应用监听的端口号

env: #注入容器内的环境变量

- name: MYSQL_ROOT_PASSWORD

value: "123456"

6.1.2 加载ReplicationController副本控制器描述文件

创建好mysql-rc.yaml后，在master节点使用kubectl命令将它发布到k8s集群中。

kubectl create -f mysql-rc.yaml

6.1.3 查看启动状态

通过查看当前的pods列表，是否已经启动成功:

6.1.4 网络异常解决方案(未出现问题可直接跳过)

注意：如果这里出现了ContainerCreating状态，那么可以尝试如下解决办法:

itcast@master:~/working$ kubectl get pods

NAME READY STATUS RESTARTS AGE

mysql-tscrh 0/1 ContainerCreating 0 17m

目前mysql-tscrh 描述文件 已经创建，但是没有启动成功. 状态是ContainerCreating 没有启动起来.

通过kubectl describe pods来查看pods的详细状态

itcast@master:~/working$ kubectl describe pods mysql

Name: mysql-tscrh

Namespace: default

Priority: 0

PriorityClassName:

Node: node1/192.168.236.178

Start Time: Mon, 17 Jun 2019 09:10:35 +0000

Labels: app=mysql

Annotations:

Status: Pending

IP:

Controlled By: ReplicationController/mysql

Containers:

mysql:

Container ID:

Image: hub.c.163.com/library/mysql

Image ID:

Port: 3306/TCP

Host Port: 0/TCP

State: Waiting

Reason: ContainerCreating

Ready: False

Restart Count: 0

Environment:

MYSQL_ROOT_PASSWORD: 123456

Mounts:

/var/run/secrets/kubernetes.io/serviceaccount from default-token-q6ggq (ro)

Conditions:

Type Status

Initialized True

Ready False

ContainersReady False

PodScheduled True

Volumes:

default-token-q6ggq:

Type: Secret (a volume populated by a Secret)

SecretName: default-token-q6ggq

Optional: false

QoS Class: BestEffort

Node-Selectors:

Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s

node.kubernetes.io/unreachable:NoExecute for 300s

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal Scheduled 22m default-scheduler Successfully assigned default/mysql-tscrh to node1

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "58d143373e767c40610587624c667d8e20dd77fa397952406a085f2ae1dc38e6" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "81d12726dbe075c64af48142638e98863231e8201ccc292f0dda1fccfa7fdaec" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "8bd77ee0176d369435ead7bd3c2675b7bbcbdc2b052cf34c784f04053a7d5288" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "0733fc209e085e96f5823a2280b012a609dace41fda967c5ae951005a8699ce6" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "91f337eb334612b2e7426d820ba4b15a9c9c549050517d459508832b69780b5f" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "48cbba9896068a774d9128a6864394e8726a0d857bae61036421ad73f5d6e3dd" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "d259778aa19418a9a429b3175b66afae3d8ffb7324ec9df492b2947dbc153460" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "3d01c00ac9eaac7b2e983402be38c1cf60c4bbd1d454aa45329ce0ca0c2bf792" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 22m kubelet, node1 Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "98879cbb0405dac3a24753dd1986070a53fe9ee9f1b819996a903c19286a2bb7" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Warning FailedCreatePodSandBox 7m49s (x838 over 22m) kubelet, node1 (combined from similar events): Failed create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "60923335b41c2d0412b279bdb6150f9b9b7eae20c4a02549e35509083c01384b" network for pod "mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

Normal SandboxChanged 2m49s (x1127 over 22m) kubelet, node1 Pod sandbox changed, it will be killed and re-created.

会看到一个错误:

"mysql-tscrh": NetworkPlugin cni failed to set up pod "mysql-tscrh_default" network: open /run/flannel/subnet.env: no such file or directory

这是缺少/run/flannel/subnet.env文件

解决办法：配置flannel网络

分别在三台服务器上执行如下步骤

创建目录

sudo mkdir -p /run/flannel

创建环境描述文件

$ sudo tee /run/flannel/subnet.env <

FLANNEL_NETWORK=10.244.0.0/16

FLANNEL_SUBNET=10.244.0.1/24

FLANNEL_MTU=1450

FLANNEL_IPMASQ=true

EOF

6.1.5 查看mysql实例集群状态

itcast@master:~/working$ kubectl get pods

NAME READY STATUS RESTARTS AGE

mysql-tscrh 0/1 Running 0 17m

如果为Running状态，则为mysql集群启动成功。

关于作者：

作者：Aceld(刘丹冰)

简书号：IT无崖子

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