K8S Pod status的状态分析

K8S Pod status的状态分析

CrashLoopBackOff: 容器退出,kubelet正在将它重启
InvalidImageName: 无法解析镜像名称
ImageInspectError: 无法校验镜像
ErrImageNeverPull: 策略禁止拉取镜像
ImagePullBackOff: 正在重试拉取
RegistryUnavailable: 连接不到镜像中心
ErrImagePull: 通用的拉取镜像出错
CreateContainerConfigError: 不能创建kubelet使用的容器配置
CreateContainerError: 创建容器失败
m.internalLifecycle.PreStartContainer  执行hook报错
RunContainerError: 启动容器失败
PostStartHookError: 执行hook报错
ContainersNotInitialized: 容器没有初始化完毕
ContainersNotReady: 容器没有准备完毕
ContainerCreating:容器创建中
PodInitializing:pod 初始化中
DockerDaemonNotReady:docker还没有完全启动
NetworkPluginNotReady: 网络插件还没有完全启动

K8S-YAML的使用及命令

YAML配置文件管理对象
对象管理:
# 创建deployment资源
kubectl create -f nginx-deployment.yaml
# 查看deployment
kubectl get deploy
# 查看ReplicaSet
kubectl get rs
# 查看pods所有标签
kubectl get pods --show-labels
# 根据标签查看pods
kubectl get pods -l app=nginx
# 滚动更新镜像
kubectl set image deployment/nginx-deployment nginx=nginx:1.11
或者
kubectl edit deployment/nginx-deployment
或者
kubectl apply -f nginx-deployment.yaml
# 实时观察发布状态:
kubectl rollout status deployment/nginx-deployment
# 查看deployment历史修订版本
kubectl rollout history deployment/nginx-deployment
kubectl rollout history deployment/nginx-deployment --revision=3
# 回滚到以前版本
kubectl rollout undo deployment/nginx-deployment
kubectl rollout undo deployment/nginx-deployment --to-revision=3
# 扩容deployment的Pod副本数量
kubectl scale deployment nginx-deployment --replicas=10
# 设置启动扩容/缩容
kubectl autoscale deployment nginx-deployment --min=10 --max=15 --cpu-percent=80

对象管理实例:vim nginx.deployment.yaml

apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.10
ports:
- containerPort: 80

服务发现实例:vim nging.service.yaml

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

清理:

# kubectl delete -f nginx-deployment.yaml

# kubectl delete -f nginx-service.yaml

POD作用:

Pod管理-创建/查询/更新/删除
基本管理:
# 创建pod资源
kubectl create -f pod.yaml
# 查看pods
kubectl get pods pod-test
# 查看pod描述
kubectl describe pod pod-test
# 替换资源
kubectl replace -f pod.yaml -force
# 删除资源
kubectl delete pod pod-test

支持三种策略:

Always:当容器终止退出后,总是重启容器,默认策略。

OnFailure:当容器异常退出(退出状态码非0)时,才重启容器。

Never:当容器终止退出,从不重启容器。

Pod实例:vim pod.yaml

apiVersion: v1
kind: Pod
metadata:
name: pod-test
labels:
os: centos
spec:
containers:
- name: hello
image: centos:7
env:
- name: Test
value: "123456"
command: ["bash","-c","while true;do date;sleep 1;done"]
restartPolicy: OnFailure

Pod管理-健康检查:

提供Probe机制,有以下两种类型:
livenessProbe
如果检查失败,将杀死容器,然后根据Pod的重启策略来决定是否
重启。
readinessProbe
如果检查失败,Kubernetes会把Pod从服务代理的分发后端剔除。
Probe支持以下三种检查方法:
httpGet
发送HTTP请求,返回200-400范围状态码为成功。
exec
执行Shell命令返回状态码是0为成功。
tcpSocket
发起TCP Socket建立成功。

实例:vim pod2.yaml

apiVersion: v1
kind: Pod
metadata:
name: nginx-pod
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.10
ports:
- containerPort: 80
livenessProbe:
httpGet:
path: /index.html
port: 80

Pod管理-数据持久化和共享:

vim pod3.yaml

apiVersion: v1
kind: Pod
metadata:
name: pod-test1
labels:
test: centos
spec:
containers:
# 第一个容器
- name: hello-write
image: centos:7
command: ["bash","-c","for i in {1..1000};do echo $i >> /data/hello;sleep 1;done"]
# 第二个容器
- name: hello-read
image: centos:7
command: ["bash","-c","for i in {1..1000};do cat $i >> /data/hello;sleep 1;done"]
volumeMounts:
- name: data
mountPath: /data
# 数据卷
volumes:
- name: data
hostPath:
path: /data

Pod端口映射:

vim pod4.yaml

apiVersion: v1
kind: Pod
metadata:
name: nginx-pod
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.10
ports:
- name: http
containerPort: 80
hostIP: 0.0.0.0
hostPort: 80
protocol: TCP
- name: https
containerPort: 443
hostIP: 0.0.0.0
hostPort: 443
protocol: TCP