Kubernetes进阶实战读书笔记:网络存储

一、nfs存储卷

kubernetes的NFS存储卷用于将某实现存在的NFS服务器上导出export的存储空间挂在到pod中以供容器使用

与emptyDir不同的是、NFS存储卷在POD对象终止后仅是被卸载而非删除、另外NFS是文件系统级共享服务,它支持同时存在的多路关在请求

1、字段详解

[root@master ~]# kubectl explain pod.spec.volumes.nfs
KIND:     Pod
VERSION:  v1

RESOURCE: nfs <Object>

DESCRIPTION:
     NFS represents an NFS mount on the host that shares a pod's lifetime More
     info: https://kubernetes.io/docs/concepts/storage/volumes#nfs

     Represents an NFS mount that lasts the lifetime of a pod. NFS volumes do
     not support ownership management or SELinux relabeling.

FIELDS:
   path	<string> -required-
   #NFS服务器导出共享的文件系统路径、必选字段
     Path that is exported by the NFS server. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#nfs

   readOnly	<boolean>
   #是以只读方式挂在、默认为false
     ReadOnly here will force the NFS export to be mounted with read-only
     permissions. Defaults to false. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#nfs

   server	<string> -required-
   #NFS服务器的ip地址、默认是false
     Server is the hostname or IP address of the NFS server. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#nfs

2、配置清单

[root@master chapter7]# cat vol-nfs1.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: vol-nfs-pod
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html
  volumes:
  - name: html
    nfs:
      path: /data/volumes
      server: node2

3、nfs server搭建

yum install nfs-utils rpcbind -y #所有节点均安装
[root@node2 volumes]# cat /etc/exports
/data/volumes 192.168.118.0/24 (rw,no_root_squash)

# 启动rpcbind服务
systemctl restart rpcbind

#启动
systemctl restart nfs-server

[root@node2 volumes]# showmount -e
Export list for node2:
/data/volumes (everyone)

4、挂载主页

[root@node2 volumes]# ls
index.html
[root@node2 volumes]# pwd
/data/volumes
[root@node2 volumes]# cat index.html 
<h1>NFS node2</h1>

5、创建运行vol-nfs.yaml

[root@master chapter7]# kubectl get pods
NAME               READY   STATUS    RESTARTS   AGE
pod-example        1/1     Running   1          9d
vol-emptydir-pod   2/2     Running   0          5d1h
vol-hostpath-pod   1/1     Running   0          4d22h
[root@master chapter7]# kubectl apply -f vol-nfs1.yaml 
pod/vol-nfs-pod created
[root@master chapter7]# kubectl get pods -o wide
NAME               READY   STATUS    RESTARTS   AGE     IP            NODE    NOMINATED NODE   READINESS GATES
pod-example        1/1     Running   1          9d      10.244.2.9    node2   <none>           <none>
vol-emptydir-pod   2/2     Running   0          5d1h    10.244.2.68   node2   <none>           <none>
vol-hostpath-pod   1/1     Running   0          4d22h   10.244.1.43   node1   <none>           <none>
vol-nfs-pod        1/1     Running   0          4m24s   10.244.1.50   node1   <none>           <none>
[root@master chapter7]# curl 10.244.1.50
<h1>NFS node2</h1>

6、删除pod数据依然存在

为了测试其数据持久化效果,下面删除pod资源vol-nfs-pod、并重建后检测数据是否依然能访问

[root@master chapter7]# kubectl delete -f vol-nfs1.yaml 
pod "vol-nfs-pod" deleted
[root@master chapter7]# kubectl get pods -o wide
NAME               READY   STATUS    RESTARTS   AGE     IP            NODE    NOMINATED NODE   READINESS GATES
pod-example        1/1     Running   1          9d      10.244.2.9    node2   <none>           <none>
vol-emptydir-pod   2/2     Running   0          5d1h    10.244.2.68   node2   <none>           <none>
vol-hostpath-pod   1/1     Running   0          4d22h   10.244.1.43   node1   <none>           <none>

[root@master chapter7]# kubectl apply -f vol-nfs1.yaml 
pod/vol-nfs-pod created
[root@master chapter7]# kubectl get pods -o wide
NAME               READY   STATUS    RESTARTS   AGE     IP            NODE    NOMINATED NODE   READINESS GATES
pod-example        1/1     Running   1          9d      10.244.2.9    node2   <none>           <none>
vol-emptydir-pod   2/2     Running   0          5d1h    10.244.2.68   node2   <none>           <none>
vol-hostpath-pod   1/1     Running   0          4d22h   10.244.1.43   node1   <none>           <none>
vol-nfs-pod        1/1     Running   0          6s      10.244.1.51   node1   <none>           <none>
[root@master chapter7]# curl 10.244.1.51
<h1>NFS node2</h1>

这里应确保实现要存在一个名为nfs.ilinux.io的NFS服务器、其输出了/data/redis目录,并授权给了kubernetes集群中的节点访问、主机和目录都可以按需进行调整

 

从上面的命令中可以看出,此前创建的键mykey及其数据在pod资源重建后依然存在、这表明再删除pod资源时、其关联的外部存储卷并不会被一同删除、如果需要清除此类的数据、需要用户通过存储系统的管理接口手动进行

二、RBD存储卷

1、配置pod资源使用RBD存储卷、满足条件

  1. 存在某可用的Ceph RBD存储集群,否则就需要创建一个
  2. 在Ceph集群中创建一个能满足Pod资源数据存储需要的存储影响(images)
  3. 在kubernetes集群内的各节点上安装Ceph客户端程序包(ceph-common)

2、字段详解

在配置RBD类型的存储卷时、需要制定要连接的目标服务器和认证信息等、这一点通常使用一下嵌套字段进行定义

[root@master ~]# kubectl explain pod.spec.volumes.rbd
KIND:     Pod
VERSION:  v1

RESOURCE: rbd <Object>

DESCRIPTION:
     RBD represents a Rados Block Device mount on the host that shares a pod's
     lifetime. More info: https://examples.k8s.io/volumes/rbd/README.md

     Represents a Rados Block Device mount that lasts the lifetime of a pod. RBD
     volumes support ownership management and SELinux relabeling.

FIELDS:
   fsType	<string>
   #要挂在的存储卷的文件系统类型,至少应该是节点操作系统支持的文件系统,如:ext4", "xfs", "ntfs".默认为"ext4" 
     Filesystem type of the volume that you want to mount. Tip: Ensure that the
     filesystem type is supported by the host operating system. Examples:
     "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
     More info: https://kubernetes.io/docs/concepts/storage/volumes#rbd

   image	<string> -required-
   #rados image的名称,必选字段
     The rados image name. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   keyring	<string>
   #RBD用户认证时的keyring文件路径,默认为/etc/ceph/keyring
     Keyring is the path to key ring for RBDUser. Default is /etc/ceph/keyring.
     More info: https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   monitors	<[]string> -required-
   #ceph存储见识其,逗号分隔的字符串列表;必选字段
     A collection of Ceph monitors. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   pool	<string>
   #rados 存储池名称,默认为RBD
     The rados pool name. Default is rbd. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   readOnly	<boolean>
   #是否以只读的方式进行访问
     ReadOnly here will force the ReadOnly setting in VolumeMounts. Defaults to
     false. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   secretRef	<Object>
   #RBD用户认证时使用的保存有相应认真信息的secret对象,会覆盖由keyring字段提供的密钥信息
     SecretRef is name of the authentication secret for RBDUser. If provided
     overrides keyring. Default is nil. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

   user	<string>
   #rados 用户名,默认为admin
     The rados user name. Default is admin. More info:
     https://examples.k8s.io/volumes/rbd/README.md#how-to-use-it

3、实验架构图

此示例依赖于实现存在的一个ceph存储集群

这里假设其监视器的地址为:172.16.0.56、172.16.0.57、172.16.0.58三个主机IP
并且集群上存储池kube中存在创建好的应先redis、此影响用油ext4文件系统
ceph客户端访问集群时需要实现完成认真之后才能进行后续的访问操作、此示例上、其认真信息保存于名为Ceph-secret的secret资源对象中

4、示例模板

[root@master chapter7]# cat vol-rbd.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: vol-rbd-pod
spec:
  containers:
  - name: redis
    image: redis:4-alpine
    ports:
    - containerPort: 6379
      name: redisport
    volumeMounts:
    - mountPath: /data
      name: redis-rbd-vol
  volumes:
    - name: redis-rbd-vol
      rbd:
        monitors:
        - '172.16.0.56:6789'
        - '172.16.0.57:6789'
        - '172.16.0.58:6789'
        pool: kube
        image: redis
        fsType: ext4
        readOnly: false
        user: admin
        secretRef:
           name: ceph-secret

三、GlusterFS存储卷

要配置pod资源使用GlusterFS存储卷、需要事先满足一下前提条件

1、前提条件

1、存储在某可用的GlusterFS存储集群、否则就要创建一个

2、在GlusterFS集群中创建一个能满足pod资源数据存储需要的卷

3、在kubernetes集群内的各节点上安装GlusterFS客户端程序包(glusterf和gluseterfs-fuse)

4、另外、若要基于GlusterFS是哦用存储卷的动态供给机制、还需要实现部署heketi,它用于为GlusterFS集群提供RESTFUL风格的管理接口

2、字段属性详解

[root@master ~]# kubectl explain pod.spec.volumes.glusterfs
KIND:     Pod
VERSION:  v1

RESOURCE: glusterfs <Object>

DESCRIPTION:
     Glusterfs represents a Glusterfs mount on the host that shares a pod's
     lifetime. More info: https://examples.k8s.io/volumes/glusterfs/README.md

     Represents a Glusterfs mount that lasts the lifetime of a pod. Glusterfs
     volumes do not support ownership management or SELinux relabeling.

FIELDS:
   endpoints	<string> -required-
   #Endpoints 资源的名称、此资源需要实现存在,用于提供Cluster集群的部分节点信息作为其访问入口;必选字段
     EndpointsName is the endpoint name that details Glusterfs topology. More
     info: https://examples.k8s.io/volumes/glusterfs/README.md#create-a-pod

   path	<string> -required-
   #用到的glusterfs集群的卷路径、如:kube-redis;必选字段
     Path is the Glusterfs volume path. More info:
     https://examples.k8s.io/volumes/glusterfs/README.md#create-a-pod

   readOnly	<boolean>
   #是否为只读卷
     ReadOnly here will force the Glusterfs volume to be mounted with read-only
     permissions. Defaults to false. More info:
     https://examples.k8s.io/volumes/glusterfs/README.md#create-a-pod

3、资源清单

[root@master chapter7]# cat vol-glusterfs.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: vol-glusterfs-pod
  labels:
    app: redis
spec:
  containers:
  - name: redis
    image: redis:alpine
    ports:
    - containerPort: 6379
      name: redisport
    volumeMounts:
    - mountPath: /data
      name: redisdata
  volumes:
    - name: redisdata
      glusterfs:
        endpoints: glusterfs-endpoints
        path: kube-redis
        readOnly: false

vol-glusterfs.yaml 它使用了glusterfs存储卷持久保存应用数据、它通过glusterfs-endpolints资源中定义的glusterfs集群节点信息接入集群

并以kube-redis卷作为pod资源的存储卷。glusterfs-endpolints资源需要在kubernetes集群中事先创建、而kube-redis则需要事先创建Gluster集群

4、创建运行

用于访问cluster集群的相关结点信息要实现保存于某特定的endpolints资源中、例如上面示例中调用的glusterfs-endpolints、此类的endpolints

资源可由用户根据实际需要手动创建、例如、下面的保存于glusterfs-endpolints.yaml文件中的资源示例中定义了三个接入相关的gluster存储集群

的节点gfs01.ilinux.io、gfs01.ilinux.io和gfs03.ilinux.io、期中的端口信息仅为满足endpolints资源必选字段要求、因此其值可以随意填写

[root@master chapter7]# cat glusterfs-endpoints.yaml 
apiVersion: v1
kind: Endpoints
metadata:
  name: glusterfs-endpoints
subsets:
  - addresses:
    - ip: 172.16.2.36
    ports:
    - port: 24007 
      name: glusterd
  - addresses:
    - ip: 172.16.2.37
    ports:
    - port: 24007 
      name: glusterd
  - addresses:
    - ip: 172.16.2.38
    ports:
    - port: 24007 
      name: glusterd

首先创建endpolints资源glusterfs-endpoints,然后再创建pod资源vol-glusterfs即可测试其数据持久化存储的效果

四、cinder存储卷

1、字段详解

openstack构建的iaas环境中时、cinder的块存储功能可为pod资源提供外部持久存储的幼小方式

在pod资源上定义使用cinder存储卷时,其可用的嵌套字段包含如下几个

[root@master ~]# kubectl explain pod.spec.volumes.cinder
KIND:     Pod
VERSION:  v1

RESOURCE: cinder <Object>

DESCRIPTION:
     Cinder represents a cinder volume attached and mounted on kubelets host
     machine. More info: https://examples.k8s.io/mysql-cinder-pd/README.md

     Represents a cinder volume resource in Openstack. A Cinder volume must
     exist before mounting to a container. The volume must also be in the same
     region as the kubelet. Cinder volumes support ownership management and
     SELinux relabeling.

FIELDS:
   fsType	<string>
   #要挂在的存储卷的问价那系统类型,至少应该是接待能操作系统支持的问价那系统
     Filesystem type to mount. Must be a filesystem type supported by the host
     operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to
     be "ext4" if unspecified. More info:
     https://examples.k8s.io/mysql-cinder-pd/README.md

   readOnly	<boolean>
   #是否以只读方式访问
     Optional: Defaults to false (read/write). ReadOnly here will force the
     ReadOnly setting in VolumeMounts. More info:
     https://examples.k8s.io/mysql-cinder-pd/README.md

   secretRef	<Object>
     Optional: points to a secret object containing parameters used to connect
     to OpenStack.

   volumeID	<string> -required-
   #用于表示cinder中的存储卷的卷标识符、必选字段
     volume id used to identify the volume in cinder. More info:
     https://examples.k8s.io/mysql-cinder-pd/README.md

2、模板示例

下面的资源清单是定义在vol-cinder.yaml 文件中的使用示例、假设在openstack环境中有创建好的cinder卷可用

[root@master chapter7]# cat vol-cinder.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: vol-cinder-pod
spec:
  containers:
   - image: mysql
      name: mysql
      args:
        - "--ignore-db-dir"
        - "lost+found"
      env:
        - name: MYSQL_ROOT_PASSWORD
          value: YOUR_PASS
      ports:
        - containerPort: 3306
          name: mysqlport
      volumeMounts:
        - name: mysqldata
          mountPath: /var/lib/mysql
  volumes:
    - name: mysqldata
      cinder:
        volumeID: e2b8d2f7-wece-90d1-a505-4acf607a90bc
        fsType: ext4

配置可用的系统环境和存储资源时、将其匹配于资源清单文件中即可完成pod资源创建、另外、kubernetes所支持的各类持久存储卷其配置使用方式各不同

posted @ 2020-08-15 18:55  活的潇洒80  阅读(70)  评论(0编辑  收藏