k8s學(xué)習(xí)筆記之statefulset應(yīng)用為何總是pending狀態(tài)

k8s pv 和 PVC 為何綁定不上

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?使用statefuset 部署有狀態(tài)應(yīng)用，應(yīng)用總是處于pending 狀態(tài),在開始之前先介紹什么是statefuset, 在 k8s 中一般用 deployment? 管理無狀態(tài)應(yīng)用，statefuset 用來管理有狀態(tài)應(yīng)用，如 redis 、MySQL 、zookper 等分布式應(yīng)用，這些應(yīng)用的啟動停止都會有嚴格的順序?

一、statefulset??

headless (無頭服務(wù)),沒有cluserIP, 資源標識符，用于生成可解析的DNS 記錄?
StatefulSet 用于pod 資源的管理
volumeClaimTemplates? 提供存儲

二、statefulset? 部署

使用nfs 做網(wǎng)絡(luò)存儲
搭建nfs
配置共享存儲目錄
創(chuàng)建pv
編排 yaml?

? ? 搭建nfs?

? ? ?yum install nfs-utils -y?

? ? mkdir -p /usr/local/k8s/redis/pv{7..12} # 創(chuàng)建掛載目錄

?cat?/etc/exports
?
?/usr/local/k8s/redis/pv7?172.16.0.0/16(rw,sync,no_root_squash)
?/usr/local/k8s/redis/pv8?172.16.0.0/16(rw,sync,no_root_squash)
?/usr/local/k8s/redis/pv9?172.16.0.0/16(rw,sync,no_root_squash)
?/usr/local/k8s/redis/pv10?172.16.0.0/16(rw,sync,no_root_squash)
?/usr/local/k8s/redis/pv11?172.16.0.0/16(rw,sync,no_root_squash

??exportfs?-avr

? ? 創(chuàng)建pv?

? ?cat?nfs_pv2.yaml

apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv7
spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??persistentVolumeReclaimPolicy:?Retain
??storageClassName:?slow
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv7"
---
apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv8

spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??storageClassName:?slow
??persistentVolumeReclaimPolicy:?Retain
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv8"
---
apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv9

spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??storageClassName:?slow
??persistentVolumeReclaimPolicy:?Retain
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv9"
---
apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv10

spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??storageClassName:?slow
??persistentVolumeReclaimPolicy:?Retain
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv10"
---
apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv11

spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??storageClassName:?slow
??persistentVolumeReclaimPolicy:?Retain
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv11"
---
apiVersion:?v1
kind:?PersistentVolume
metadata:
??name:?nfs-pv12

spec:
??capacity:
????storage:?500M
??accessModes:
????-?ReadWriteMany
??storageClassName:?slow
??persistentVolumeReclaimPolicy:?Retain
??nfs:
????server:?172.16.0.59
????path:?"/usr/local/k8s/redis/pv12"

? ?kubectl apply -f nfs_pv2.yaml

? ?

?查看 # 創(chuàng)建成功

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

? 編寫yaml 編排應(yīng)用

apiVersion:?v1
kind:?Service
metadata:
??name:?myapp
??labels:
????app:?myapp
spec:
??ports:
??-?port:?80
????name:?web
??clusterIP:?None
??selector:
????app:?myapp-pod
---
apiVersion:?apps/v1
kind:?StatefulSet
metadata:
??name:?myapp
spec:
??serviceName:?myapp
??replicas:?3
??selector:
????matchLabels:
??????app:?myapp-pod
??template:
????metadata:
??????labels:
????????app:?myapp-pod
????spec:
??????containers:
??????-?name:?myapp
????????image:?ikubernetes/myapp:v1
????????resources:
??????????requests:
????????????cpu:?"500m"
????????????memory:?"500Mi"
????????ports:
????????-?containerPort:?80
??????????name:?web
????????volumeMounts:
????????-?name:?myappdata
??????????mountPath:?/usr/share/nginx/html
??volumeClaimTemplates:
??-?metadata:
??????name:?myappdata
????spec:
??????accessModes:?["ReadWriteOnce"]
??????storageClassName:?"slow"
??????resources:
????????requests:
??????????storage:?400Mi

??kubectl create -f new-stateful.yaml?

? 查看headless 創(chuàng)建成功

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

?查看pod 是否創(chuàng)建成功

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

查看pvc 是否創(chuàng)建成功

? k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

pod 啟動沒有成功，依賴于pvc ，查看pvc 的日志,沒有找到對應(yīng)的pvc,明明寫了啊

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

查看關(guān)聯(lián)信息，有下面這個屬性

storageClassName:?"slow"

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài) ?

三、statefulset? 排障

? pvc 無法創(chuàng)建，導(dǎo)致pod 無法正常啟動，yaml 文件重新檢查了幾遍，

思考的方向：pvc 如何綁定pv ，通過storageClassName 去關(guān)聯(lián)，pv 也創(chuàng)建成功了，也存在storageClassName: slow 這個屬性，結(jié)果愣是找不到

。。。。

后面檢查pv 和pvc 的權(quán)限是否一直

發(fā)現(xiàn)pv 設(shè)置的權(quán)限

volumeClaimTemplates: 聲明的pvc 權(quán)限

k8s 學(xué)習(xí)筆記之 statefulset 應(yīng)用為何總是pending 狀態(tài)

兩邊的權(quán)限不一致，

操作?

刪除 pvc??kubectl delete pvc myappdata-myapp-0 -n daemon

刪除 yaml 文件， kubectl delete -f new-stateful.yaml -n daemon

嘗試修改??accessModes: ["ReadWriteMany"]

再次查看

提示：pv 和PVC 設(shè)定權(quán)限注

四、statefulset 測試，域名解析

kubectl exec -it myapp-0 sh -n daemon

nslookup myapp-0.myapp.daemon.svc.cluster.local

解析的規(guī)則如下

? ? ? ? ??myapp-0? ? ? ?myapp? ? ? ? ? ? ? ? ? ? ? ? ?daemon??

FQDN： $(podname).(headless server name).namespace.svc.cluster.local

容器里面如沒有nsllokup ,需要安裝對應(yīng)的包，busybox 可以提供類似的功能

?提供yaml 文件

apiVersion:?v1
kind:?Pod
metadata:
??name:?busybox
??namespace:?daemon
spec:
??containers:
??-?name:?busybox
????image:?busybox:1.28.4
????command:
??????-?sleep
??????-?"7600"
????resources:
??????requests:
????????memory:?"200Mi"
????????cpu:?"250m"
????imagePullPolicy:?IfNotPresent
??restartPolicy:?Never