k8s-容器资源管理

k8s 容器资源管理

1.  定义配置文件使用最新的api
2.  配置文件统一版本管理，使用git，svn等
3.  使用yaml格式配置文件（k8s支持json）
4.  可以将不同的对象合并成一个配置文件
5.  不要没有必要设置默认值
6.  在注释中说明配置的作用

1. 获取api

[root@master ~]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1

2. 创建 nginx-deployment.yaml 配置文件

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deployment # 创建deployment的名称
  
spec: #具体容器和控制器的所有配置
  replicas: 3 # 副本数量
  selector: # 选择器
    matchLabels:
      app: nginx # 匹配下面的template.metadata.labels
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers: # 容器的说明
        - name: nginx
          image: nginx:1.10
          ports:
            - containerPort: 80

3. 创建资源

[root@master ~]# kubectl create -f nginx-deployment.yaml 
deployment "nginx-deployment" created

4. 查看资源

[root@master ~]# kubectl get deploy
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx              3         3         3            2           49d
nginx-deployment   3         3         3            0           5m

5. 创建nginx-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
  labels:
    app: nginx
spec:
  ports:
    - port: 88
      targetPort: 80
  selector:
    app: nginx

6. 创建资源

[root@master ~]# kubectl get svc -o wide |grep app=nginx
nginx-service   ClusterIP   10.10.10.27   <none>        88/TCP         1m        app=nginx

7. 测试端口是不是联通

# 在node01上测试
[root@node01 ~]# hostname
node01
[root@node01 ~]# curl -I 10.10.10.27:88
HTTP/1.1 200 OK
Server: nginx/1.10.3
Date: Sun, 16 Feb 2020 07:23:11 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 31 Jan 2017 15:01:11 GMT
Connection: keep-alive
ETag: "5890a6b7-264"
Accept-Ranges: bytes

8. 查看端口访问日志

[root@master ~]# kubectl logs -f nginx-deployment-58d6d6ccb8-wbgdx
172.17.19.0 - - [16/Feb/2020:07:21:42 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.29.0" "-"
172.17.19.0 - - [16/Feb/2020:07:23:11 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.29.0" "-"
172.17.98.1 - - [16/Feb/2020:07:27:19 +0000] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.29.0" "-"

Pod 管理

1. 创建/查询/更新/删除

[root@master ~]# vim nginx-pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
    - name: nginx
      image: nginx:1.12

# 创建
[root@master ~]# kubectl create -f nginx-pod.yaml 
pod "nginx-pod" created


## 查看
[root@master ~]# kubectl get pod nginx-pod
NAME        READY     STATUS              RESTARTS   AGE
nginx-pod   0/1       ContainerCreating   0          1m


[root@master ~]# kubectl describe pod nginx-pod
Name:         nginx-pod
Namespace:    default
Node:         192.168.10.157/192.168.10.157
Start Time:   Sun, 16 Feb 2020 02:45:18 -0500
Labels:       app=nginx
Annotations:  <none>
Status:       Pending
IP:           
Containers:
  nginx:
    Container ID:   
    Image:          nginx:1.12


#删除pod
[root@master ~]# kubectl delete -f nginx-pod.yaml 
pod "nginx-pod" deleted

# 替换
[root@master ~]# kubectl replace -f nginx-pod.yaml --force
[root@master ~]# kubectl apply -f nginx-pod.yaml

2. 资源控制

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
    - name: nginx
      image: nginx
      resources: # 资源限制
        requests: # 需要多少
          memory: "64Mi"
          cpu: "250m"
        limits: # 最高使用多少
          memory: "128Mi"
          cpu: "500m"

3. 调度约束

# 主要是将pod发布到不同的环境，dev test prod 等
apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  # nodeName: node01 # nodeName： 强制约束Pod调度到指定Node节点上
  nodeSelector: # 通过label-selector 机制选择节点
    env_role: dev
  containers:
    - name: nginx
      image: nginx
      resources:
        requests:
          memory: "64Mi"
          cpu: "250m"
        limits:
          memory: "128Mi"
          cpu: "500m"

# 创建并查看
[root@master ~]# kubectl get pod nginx-pod -o wide
NAME        READY     STATUS              RESTARTS   AGE       IP        NODE
nginx-pod   0/1       ContainerCreating   0          18s       <none>    192.168.10.157

# 查看node
[root@master ~]# kubectl describe node 192.168.10.157
Name:               192.168.10.157
Roles:              <none>
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/hostname=192.168.10.157
Annotations:        node.alpha.kubernetes.io/ttl=0
                    volumes.kubernetes.io/controller-managed-attach-detach=true
Taints:             <none>
CreationTimestamp:  Sat, 28 Dec 2019 22:05:14 -0500
Conditions:
  Type             Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----             ------  -----------------                 ------------------                ------                       -------
  OutOfDisk        False   Sun, 16 Feb 2020 03:12:16 -0500   Sat, 28 Dec 2019 22:05:14 -0500   KubeletHasSufficientDisk     kubelet has sufficient disk space available
  MemoryPressure   False   Sun, 16 Feb 2020 03:12:16 -0500   Sat, 28 Dec 2019 22:05:14 -0500   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure     False   Sun, 16 Feb 2020 03:12:16 -0500   Sat, 28 Dec 2019 22:05:14 -0500   KubeletHasNoDiskPressure     kubelet has no disk pressure
  Ready            True    Sun, 16 Feb 2020 03:12:16 -0500   Sat, 15 Feb 2020 21:23:43 -0500   KubeletReady                 kubelet is posting ready status
Addresses:
  InternalIP:  192.168.10.157
  Hostname:    192.168.10.157
Capacity:
 cpu:     2
 memory:  1863088Ki
 pods:    110
Allocatable:
 cpu:     2
 memory:  1760688Ki
 pods:    110
System Info:
 Machine ID:                 62e88a67a90446a2a526e4a44d747252
 System UUID:                C4364D56-AF69-D8E2-B66F-9248ABA78285
 Boot ID:                    72d46f77-e850-4051-8575-5220ddfeea26
 Kernel Version:             3.10.0-1062.9.1.el7.x86_64
 OS Image:                   CentOS Linux 7 (Core)
 Operating System:           linux
 Architecture:               amd64
 Container Runtime Version:  docker://19.3.5
 Kubelet Version:            v1.9.1
 Kube-Proxy Version:         v1.9.1
ExternalID:                  192.168.10.157
Non-terminated Pods:         (5 in total)
  Namespace                  Name                                     CPU Requests  CPU Limits  Memory Requests  Memory Limits
  ---------                  ----                                     ------------  ----------  ---------------  -------------
  default                    nginx-8586cf59-ms8tr                     0 (0%)        0 (0%)      0 (0%)           0 (0%)
  default                    nginx-deployment-58d6d6ccb8-wbgdx        0 (0%)        0 (0%)      0 (0%)           0 (0%)
  default                    nginx-pod                                250m (12%)    500m (25%)  64Mi (3%)        128Mi (7%)
  kube-system                kubernetes-dashboard-67c665dd8d-p5xm2    0 (0%)        0 (0%)      0 (0%)           0 (0%)
  kubernetes-dashboard       kubernetes-dashboard-9df4d7b65-hnxsv     0 (0%)        0 (0%)      0 (0%)           0 (0%)
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  CPU Requests  CPU Limits  Memory Requests  Memory Limits
  ------------  ----------  ---------------  -------------
  250m (12%)    500m (25%)  64Mi (3%)        128Mi (7%)
Events:         <none>

## 给node里面的label为
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/hostname=192.168.10.157
## 给该node增加一个标签
[root@master ~]# kubectl label nodes 192.168.10.157 env_role=dev
node "192.168.10.157" labeled

## 再次查看标签
[root@master ~]# kubectl describe node 192.168.10.157

Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    env_role=dev
                    kubernetes.io/hostname=192.168.10.157

4. Pod的重启策略

参考： https://blog.51cto.com/2032872/2332944?source=dra

## 三种重启策略 Always、OnFailure和Never，默认值为Always。
Always：当容器失效时，由kubelet自动重启该容器。
OnFailure：当容器终止运行且退出码不为0时，由kubelet自动重启该容器。
Never：不论容器运行状态如何，kubelet都不会重启该容器。

# Pod的重启策略与控制方式息息相关，当前可用于管理Pod的控制器包括ReplicationController、Job、DaemonSet及直接通过kubelet管理（静态Pod）。每种控制器对Pod的重启策略要求如下：

RC和DaemonSet：必须设置为Always，需要保证该容器持续运行。
Job和CronJob：OnFailure或Never，确保容器执行完成后不再重启。
kubelet：在Pod失效时自动重启它，不论将RestartPolicy设置为什么值，也不会对Pod进行健康检查。

5. Pod的健康检查机制

参考： https://www.cnblogs.com/ssgeek/p/11351376.html

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
    - name: nginx
      image: nginx
      ports:
        - containerPort: 80
      livenessProbe:
        httpGet:
          port: 80
          path: /index.html

6. 问题定位

1. kubectl describe TYPE NAME_PREFIX
2. kubectl logs NAME
3. kubectl exec -it NAME bash