kubernetes搭建rook-ceph

简介

• Rook官网：https://rook.io
• Rook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：https://ceph.com/
• 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

---

有道笔记原文：http://note.youdao.com/noteshare?id=281719f1f0374f787effc90067e0d5ad&sub=0B59EA339D4A4769B55F008D72C1A4C0

环境

centos 7.5
kernel 4.18.7-1.el7.elrepo.x86_64 docker 18.06 kubernetes v1.12.2 kubeadm部署： 网络: canal DNS: coredns 集群成员： 192.168.1.1 kube-master 192.168.1.2 kube-node1 192.168.1.3 kube-node2 192.168.1.4 kube-node3 192.168.1.5 kube-node4 所有node节点准备一块200G的磁盘：/dev/sdb 

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准备工作

• 所有节点开启ip_forward

cat <<EOF >  /etc/sysctl.d/ceph.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --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 $HOME
git clone https://github.com/rook/rook.git

cd rook cd cluster/examples/kubernetes/ceph kubectl 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-agent

kubectl -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=enabled

kubectl 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: v1
kind: Namespace
metadata:
  name: rook-ceph
---
apiVersion: v1
kind: ServiceAccount metadata: name: rook-ceph-cluster namespace: rook-ceph --- kind: Role apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: rook-ceph-cluster namespace: rook-ceph rules: - apiGroups: [""] resources: ["configmaps"] verbs: [ "get", "list", "watch", "create", "update", "delete" ] --- # Allow the operator to create resources in this cluster's namespace kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: rook-ceph-cluster-mgmt namespace: rook-ceph roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: rook-ceph-cluster-mgmt subjects: - kind: ServiceAccount name: rook-ceph-system namespace: rook-ceph-system --- # Allow the pods in this namespace to work with configmaps kind: RoleBinding apiVersion: rbac.authorization.k8s.io/v1beta1 metadata: name: rook-ceph-cluster namespace: rook-ceph roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: rook-ceph-cluster subjects: - kind: ServiceAccount name: rook-ceph-cluster namespace: rook-ceph --- apiVersion: ceph.rook.io/v1beta1 kind: Cluster metadata: name: rook-ceph namespace: rook-ceph spec: 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 https://hub.docker.com/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: 3 allowMultiplePerNode: 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-dashboard network: # 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-mon operator: In values: - enabled osd: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: ceph-osd operator: In values: - enabled mgr: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: nodeSelectorTerms: - matchExpressions: - key: ceph-mgr operator: In values: - enabled resources: # 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 selection useAllNodes: false useAllDevices: false deviceFilter: 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osd nodes: - 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." 

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开始部署ceph

• 部署ceph

kubectl 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Pod

kubectl -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
  

  

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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 -tanl
kubectl -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.html

apiVersion: ceph.rook.io/v1beta1
kind: Pool
metadata:
  #这个name就是创建成ceph pool之后的pool名字
  name: replicapool
  namespace: rook-ceph
spec: 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/v1 kind: StorageClass metadata: name: ceph # StorageClass的名字，pvc调用时填的名字 provisioner: ceph.rook.io/block parameters: 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 be clusterNamespace: 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：Retain reclaimPolicy: Retain 

• 创建StorageClass

kubectl apply -f storageclass.yaml kubectl get storageclasses.storage.k8s.io -n rook-ceph kubectl describe storageclasses.storage.k8s.io -n rook-ceph 

---

• 创建个nginx pod尝试挂载

cat << EOF > nginx.yaml
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nginx-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi
  storageClassName: ceph

---
apiVersion: v1 kind: Service metadata: name: nginx spec: selector: app: nginx ports: - port: 80 name: nginx-port targetPort: 80 protocol: TCP --- apiVersion: apps/v1 kind: Deployment metadata: name: nginx spec: replicas: 1 selector: matchLabels: app: nginx template: metadata: name: nginx labels: app: nginx spec: containers: - name: nginx image: nginx ports: - containerPort: 80 volumeMounts: - mountPath: /html name: http-file volumes: - name: http-file persistentVolumeClaim: claimName: nginx-pvc EOF kubectl 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.yaml

kubectl get pv,pvc
# 可以看到，pod和pvc都已经被删除了，但是pv还在！！！

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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 -w
kubectl -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 -w
kubectl -n rook-ceph get pod -o wide

# 最后记得删除宿主机的/var/lib/rook文件夹