Pod常见状态分析
常见状态和原因
kube-scheduler
Pending：调度不成功
kubelet
ImagePullBackOff：镜像拉取失败
Running：容器已创建并且启动
Ready：容器可以提供服务
CrashLoopBackOff：容器退出后kubelet拉起新容器
如果没有配置livenessProbe或者readinessProbe，那么对应的检查默认成功。
通过livenessProbe和readinessProbe是容器Ready的必要条件。
实验1：Pod重启次数计算方式
创建初始化容器后Pod重启次数是初始化容器重启次数之和
创建业务容器后Pod重启次数是业务容器重启次数之和
apiVersion: apps/v1
kind: Deployment
metadata:
name: busybox-deployment
spec:
replicas: 1
selector:
matchLabels:
app: busybox
template:
metadata:
labels:
app: busybox
spec:
containers:
- name: busybox1
image: busybox:1.36
command: ["sh", "-c", "sleep 10000"]
- name: busybox2
image: busybox:1.36
command: ["sh", "-c", "sleep 10000"]
readinessProbe:
tcpSocket:
port: 100
initialDelaySeconds: 5
initContainers:
- name: check1
image: busybox:1.36
command: ["sh", "-c", "cat /test/abc"]
volumeMounts:
- mountPath: /test
name: root
- name: check2
image: busybox:1.36
command: ["sh", "-c", "cat /test/abc"]
volumeMounts:
- mountPath: /test
name: root
volumes:
- name: root
hostPath:
path: /root实验2：livenessProbe成功而readinessProbe失败进入不了Ready
apiVersion: apps/v1
kind: Deployment
metadata:
name: busybox-deployment
spec:
replicas: 1
selector:
matchLabels:
app: busybox
template:
metadata:
labels:
app: busybox
spec:
containers:
- name: busybox1
image: busybox:1.36
command: ["sh", "-c", "sleep 10000"]
- name: busybox2
image: busybox:1.36
command: ["sh", "-c", "sleep 10000"]
readinessProbe:
tcpSocket:
port: 100
initialDelaySeconds: 5查询异常Pod
kubectl get pod -A | grep -v Completed | tr '/' ' ' | awk '$3!=$4||$5!="Running"'
参考资料
pod常见状态及故障原因