简介
Rook官网：https://rook.ioRook是云原生计算基金会(CNCF)的孵化级项目.Rook是Kubernetes的开源云本地存储协调器，为各种存储解决方案提供平台，框架和支持，以便与云原生环境本地集成。至于CEPH，官网在这：/ceph官方提供的helm部署，至今我没成功过，所以转向使用rook提供的方案环境
centos 7.5kernel 4.18.7-1.el7.elrepo.x86_64docker 18.06kubernetes v1.12.2kubeadm部署：网络: canalDNS: coredns集群成员： 192.168.1.1 kube-master192.168.1.2 kube-node1192.168.1.3 kube-node2192.168.1.4 kube-node3192.168.1.5 kube-node4所有node节点准备一块200G的磁盘：/dev/sdb
准备工作
所有节点开启ip_forwardcat <<EOF > /etc/sysctl.d/ceph.confnet.ipv4.ip_forward = 1net.bridge.bridge-nf-call-ip6tables = 1net.bridge.bridge-nf-call-iptables = 1EOFsysctl --system
开始部署Operator
部署Rook Operator#无另外说明，全部操作都在master操作cd $HOMEgit clone /rook/rook.gitcd rookcd cluster/examples/kubernetes/cephkubectl apply -f operator.yaml
查看Operator的状态
#执行apply之后稍等一会。#operator会在集群内的每个主机创建两个pod:rook-discover,rook-ceph-agentkubectl -n rook-ceph-system get pod -o wide
给节点打标签
运行ceph-mon的节点打上：ceph-mon=enabledkubectl label nodes {kube-node1,kube-node2,kube-node3} ceph-mon=enabled
运行ceph-osd的节点，也就是存储节点，打上：ceph-osd=enabled
kubectl label nodes {kube-node1,kube-node2,kube-node3} ceph-osd=enabled
运行ceph-mgr的节点，打上：ceph-mgr=enabled
#mgr只能支持一个节点运行，这是ceph跑k8s里的局限kubectl label nodes kube-node1 ceph-mgr=enabled
配置cluster.yaml文件
官方配置文件详解：https://rook.io/docs/rook/v0.8/ceph-cluster-crd.html
文件中有几个地方要注意：
dataDirHostPath: 这个路径是会在宿主机上生成的，保存的是ceph的相关的配置文件，再重新生成集群的时候要确保这个目录为空，否则mon会无法启动useAllDevices: 使用所有的设备，建议为false，否则会把宿主机所有可用的磁盘都干掉useAllNodes：使用所有的node节点，建议为false，肯定不会用k8s集群内的所有node来搭建ceph的databaseSizeMB和journalSizeMB：当磁盘大于100G的时候，就注释这俩项就行了
本次实验用到的 cluster.yaml 文件内容如下：
apiVersion: v1kind: Namespacemetadata:name: rook-ceph---apiVersion: v1kind: ServiceAccountmetadata:name: rook-ceph-clusternamespace: rook-ceph---kind: RoleapiVersion: rbac.authorization.k8s.io/v1beta1metadata:name: rook-ceph-clusternamespace: rook-cephrules:- apiGroups: [""]resources: ["configmaps"]verbs: [ "get", "list", "watch", "create", "update", "delete" ]---# Allow the operator to create resources in this cluster's namespacekind: RoleBindingapiVersion: rbac.authorization.k8s.io/v1beta1metadata:name: rook-ceph-cluster-mgmtnamespace: rook-cephroleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: rook-ceph-cluster-mgmtsubjects:- kind: ServiceAccountname: rook-ceph-systemnamespace: rook-ceph-system---# Allow the pods in this namespace to work with configmapskind: RoleBindingapiVersion: rbac.authorization.k8s.io/v1beta1metadata:name: rook-ceph-clusternamespace: rook-cephroleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: rook-ceph-clustersubjects:- kind: ServiceAccountname: rook-ceph-clusternamespace: rook-ceph---apiVersion: ceph.rook.io/v1beta1kind: Clustermetadata:name: rook-cephnamespace: rook-cephspec:cephVersion:# The container image used to launch the Ceph daemon pods (mon, mgr, osd, mds, rgw).# v12 is luminous, v13 is mimic, and v14 is nautilus.# RECOMMENDATION: In production, use a specific version tag instead of the general v13 flag, which pulls the latest release and could result in different# versions running within the cluster. See tags available at /r/ceph/ceph/tags/.image: ceph/ceph:v13# Whether to allow unsupported versions of Ceph. Currently only luminous and mimic are supported.# After nautilus is released, Rook will be updated to support nautilus.# Do not set to true in production.allowUnsupported: false# The path on the host where configuration files will be persisted. If not specified, a kubernetes emptyDir will be created (not recommended).# Important: if you reinstall the cluster, make sure you delete this directory from each host or else the mons will fail to start on the new cluster.# In Minikube, the '/data' directory is configured to persist across reboots. Use "/data/rook" in Minikube environment.dataDirHostPath: /var/lib/rook# The service account under which to run the daemon pods in this cluster if the default account is not sufficient (OSDs)serviceAccount: rook-ceph-cluster# set the amount of mons to be started# count可以定义ceph-mon运行的数量，这里默认三个就行了mon:count: 3allowMultiplePerNode: true# enable the ceph dashboard for viewing cluster status# 开启ceph资源面板dashboard:enabled: true# serve the dashboard under a subpath (useful when you are accessing the dashboard via a reverse proxy)# urlPrefix: /ceph-dashboardnetwork:# toggle to use hostNetwork# 使用宿主机的网络进行通讯# 使用宿主机的网络貌似可以让集群外的主机挂载ceph# 但是我没试过，有兴趣的兄弟可以试试改成true# 反正这里只是集群内用，我就不改了hostNetwork: false# To control where various services will be scheduled by kubernetes, use the placement configuration sections below.# The example under 'all' would have all services scheduled on kubernetes nodes labeled with 'role=storage-node' and# tolerate taints with a key of 'storage-node'.placement:# all:#nodeAffinity:# requiredDuringSchedulingIgnoredDuringExecution:#nodeSelectorTerms:#- matchExpressions:# - key: role# operator: In# values:# - storage-node#podAffinity:#podAntiAffinity:#tolerations:#- key: storage-node# operator: Exists# The above placement information can also be specified for mon, osd, and mgr components# mon:# osd:# mgr:# nodeAffinity：通过选择标签的方式，可以限制pod被调度到特定的节点上# 建议限制一下，为了让这几个pod不乱跑mon:nodeAffinity:requiredDuringSchedulingIgnoredDuringExecution:nodeSelectorTerms:- matchExpressions:- key: ceph-monoperator: Invalues:- enabledosd:nodeAffinity:requiredDuringSchedulingIgnoredDuringExecution:nodeSelectorTerms:- matchExpressions:- key: ceph-osdoperator: Invalues:- enabledmgr:nodeAffinity:requiredDuringSchedulingIgnoredDuringExecution:nodeSelectorTerms:- matchExpressions:- key: ceph-mgroperator: Invalues:- enabledresources:# The requests and limits set here, allow the mgr pod to use half of one CPU core and 1 gigabyte of memory# mgr:#limits:# cpu: "500m"# memory: "1024Mi"#requests:# cpu: "500m"# memory: "1024Mi"# The above example requests/limits can also be added to the mon and osd components# mon:# osd:storage: # cluster level storage configuration and selectionuseAllNodes: falseuseAllDevices: falsedeviceFilter:location:config:# The default and recommended storeType is dynamically set to bluestore for devices and filestore for directories.# Set the storeType explicitly only if it is required not to use the default.# storeType: bluestore# databaseSizeMB: "1024" # this value can be removed for environments with normal sized disks (100 GB or larger)# journalSizeMB: "1024" # this value can be removed for environments with normal sized disks (20 GB or larger)# Cluster level list of directories to use for storage. These values will be set for all nodes that have no `directories` set.# directories:# - path: /rook/storage-dir# Individual nodes and their config can be specified as well, but 'useAllNodes' above must be set to false. Then, only the named# nodes below will be used as storage resources. Each node's 'name' field should match their 'kubernetes.io/hostname' label.#建议磁盘配置方式如下：#name: 选择一个节点，节点名字为kubernetes.io/hostname的标签，也就是kubectl get nodes看到的名字#devices: 选择磁盘设置为OSD# - name: "sdb":将/dev/sdb设置为osdnodes:- name: "kube-node1"devices:- name: "sdb"- name: "kube-node2"devices:- name: "sdb"- name: "kube-node3"devices:- name: "sdb"#directories: # specific directories to use for storage can be specified for each node#- path: "/rook/storage-dir"#resources:# limits:#cpu: "500m"#memory: "1024Mi"# requests:#cpu: "500m"#memory: "1024Mi"# - name: "172.17.4.201"#devices: # specific devices to use for storage can be specified for each node#- name: "sdb"#- name: "sdc"#config: # configuration can be specified at the node level which overrides the cluster level config# storeType: filestore# - name: "172.17.4.301"#deviceFilter: "^sd."
开始部署ceph
部署cephkubectl apply -f cluster.yaml# cluster会在rook-ceph这个namesapce创建资源# 盯着这个namesapce的pod你就会发现，它在按照顺序创建Podkubectl -n rook-ceph get pod -o wide -w# 看到所有的pod都Running就行了# 注意看一下pod分布的宿主机，跟我们打标签的主机是一致的kubectl -n rook-ceph get pod -o wide
切换到其他主机看一下磁盘
切换到kube-node1
lsblk
切换到kube-node3
lsblk
配置ceph dashboard
看一眼dashboard在哪个service上kubectl -n rook-ceph get service#可以看到dashboard监听了8443端口
创建个nodeport类型的service以便集群外部访问
kubectl apply -f dashboard-external-https.yaml# 查看一下nodeport在哪个端口ss -tanlkubectl -n rook-ceph get service
找出Dashboard的登陆账号和密码
MGR_POD=`kubectl get pod -n rook-ceph | grep mgr | awk '{print $1}'`kubectl -n rook-ceph logs $MGR_POD | grep password
打开浏览器输入任意一个Node的IP+nodeport端口这里我的就是：https://192.168.1.2:30290
配置ceph为storageclass
官方给了一个样本文件：storageclass.yaml这个文件使用的是RBD 块存储pool创建详解：https://rook.io/docs/rook/v0.8/ceph-pool-crd.htmlapiVersion: ceph.rook.io/v1beta1kind: Poolmetadata:#这个name就是创建成ceph pool之后的pool名字name: replicapoolnamespace: rook-cephspec:replicated:size: 1# size 池中数据的副本数,1就是不保存任何副本failureDomain: osd# failureDomain：数据块的故障域，# 值为host时，每个数据块将放置在不同的主机上# 值为osd时，每个数据块将放置在不同的osd上---apiVersion: storage.k8s.io/v1kind: StorageClassmetadata:name: ceph# StorageClass的名字，pvc调用时填的名字provisioner: ceph.rook.io/blockparameters:pool: replicapool# Specify the namespace of the rook cluster from which to create volumes.# If not specified, it will use `rook` as the default namespace of the cluster.# This is also the namespace where the cluster will beclusterNamespace: rook-ceph# Specify the filesystem type of the volume. If not specified, it will use `ext4`.fstype: xfs# 设置回收策略默认为：RetainreclaimPolicy: Retain
创建StorageClass
kubectl apply -f storageclass.yamlkubectl get storageclasses.storage.k8s.io -n rook-cephkubectl describe storageclasses.storage.k8s.io -n rook-ceph
创建个nginx pod尝试挂载
cat << EOF > nginx.yaml---apiVersion: v1kind: PersistentVolumeClaimmetadata:name: nginx-pvcspec:accessModes:- ReadWriteManyresources:requests:storage: 1GistorageClassName: ceph---apiVersion: v1kind: Servicemetadata:name: nginxspec:selector:app: nginxports: - port: 80name: nginx-porttargetPort: 80protocol: TCP---apiVersion: apps/v1kind: Deploymentmetadata:name: nginxspec:replicas: 1selector:matchLabels:app: nginxtemplate:metadata:name: nginxlabels:app: nginxspec:containers:- name: nginximage: nginxports:- containerPort: 80volumeMounts:- mountPath: /htmlname: http-filevolumes:- name: http-filepersistentVolumeClaim:claimName: nginx-pvcEOFkubectl apply -f nginx.yaml
查看pv,pvc是否创建了
kubectl get pv,pvc# 看一下nginx这个pod也运行了kubectl get pod
删除这个pod,看pv是否还存在
kubectl delete -f nginx.yamlkubectl get pv,pvc# 可以看到，pod和pvc都已经被删除了，但是pv还在！！！
添加新的OSD进入集群
这次我们要把node4添加进集群，先打标签kubectl label nodes kube-node4 ceph-osd=enabled
重新编辑cluster.yaml文件
# 原来的基础上添加node4的信息cd $HOME/rook/cluster/examples/kubernetes/ceph/vi cluster.yam
apply一下cluster.yaml文件
kubectl apply -f cluster.yaml# 盯着rook-ceph名称空间,集群会自动添加node4进来kubectl -n rook-ceph get pod -o wide -wkubectl -n rook-ceph get pod -o wide
去node4节点看一下磁盘
lsblk
再打开dashboard看一眼
删除一个节点
去掉node3的标签kubectl label nodes kube-node3 ceph-osd-
重新编辑cluster.yaml文件
# 删除node3的信息cd $HOME/rook/cluster/examples/kubernetes/ceph/vi cluster.yam
apply一下cluster.yaml文件
kubectl apply -f cluster.yaml# 盯着rook-ceph名称空间kubectl -n rook-ceph get pod -o wide -wkubectl -n rook-ceph get pod -o wide# 最后记得删除宿主机的/var/lib/rook文件夹
常见问题
官方解答：https://rook.io/docs/rook/v0.8/common-issues.html
当机器重启之后，osd无法正常的Running，无限重启
#解决办法：# 标记节点为 drain 状态kubectl drain <node-name> --ignore-daemonsets --delete-local-data# 然后再恢复kubectl uncordon <node-name>
