k8s pod使用iscsi块存储

k8s pod使用iscsi块存储

一、iscsi设备建立块存储

本例子iscsi设备为tgtd+lvm

lvcreate -V 1G -T volgrp/lvpool -n node4   #添加块设备
[root@target ~]# lvs
node4  volgrp Vwi-aotz--   1.00g lvpool        4.79 

配置/etc/tgt/targets.conf添加以下配置

<target iqn.2001-04.com.example:storage.kube.sys1.xyz>
    backing-store /dev/volgrp/node4
    initiator-address 192.168.3.71
    initiator-address 192.168.3.74
    initiator-address 192.168.3.75
</target>

重启服务

systemctl restart tgtd.service

二、k8s pod挂载

编辑yaml文件iscsipod.yaml

---
apiVersion: v1
kind: Pod
metadata:
  name: iscsipd
spec:
  containers:
  - name: iscsipd-rw
    image: httpd
    volumeMounts:
    - mountPath: "/mnt"
      name: iscsipd-rw
  volumes:
  - name: iscsipd-rw
    iscsi:
      targetPortal: 192.168.3.4:3260
      portals: ['192.168.3.4:3260']
      iqn: iqn.2001-04.com.example:storage.kube.sys1.xyz
      lun: 1
      fsType: ext4
      readOnly: true

执行：

kubectl apply -f iscsipod.yaml

查看pod的信息：

 kubectl describe pod iscsipd
Name:         iscsipd
Namespace:    default
Priority:     0
Node:         k8s-worker02/192.168.3.75
Start Time:   Tue, 23 Feb 2021 16:53:19 +0800
Labels:       <none>
Annotations:  cni.projectcalico.org/podIP: 10.255.2.9/32
Status:       Running
IP:           10.255.2.9
IPs:
  IP:  10.255.2.9
Containers:
  iscsipd-rw:
    Container ID:   docker://bc10d08edcca5a04ba423dfe9b3932dad73da2174641d78d95a8b2abe778490e
    Image:          httpd
    Image ID:       docker-pullable://httpd@sha256:2fab99fb3b1c7ddfa99d7dc55de8dad0a62dbe3e7c605d78ecbdf2c6c49fd636
    Port:           <none>
    Host Port:      <none>
    State:          Running
      Started:      Tue, 23 Feb 2021 16:53:50 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /mnt from iscsipd-rw (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-88ss9 (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  iscsipd-rw:
    Type:               ISCSI (an ISCSI Disk resource that is attached to a kubelet's host machine and then exposed to the pod)
    TargetPortal:       192.168.3.4:3260
    IQN:                iqn.2001-04.com.example:storage.kube.sys1.xyz
    Lun:                1
    ISCSIInterface      default
    FSType:             ext4
    ReadOnly:           true
    Portals:            [192.168.3.4:3260]
    DiscoveryCHAPAuth:  false
    SessionCHAPAuth:    false
    SecretRef:          nil
    InitiatorName:      <none>
  default-token-88ss9:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-88ss9
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason                  Age    From                     Message
  ----    ------                  ----   ----                     -------
  Normal  Scheduled               8m5s   default-scheduler        Successfully assigned default/iscsipd to k8s-worker02
  Normal  SuccessfulAttachVolume  8m5s   attachdetach-controller  AttachVolume.Attach succeeded for volume "iscsipd-rw"
  Normal  Pulling                 7m36s  kubelet, k8s-worker02    Pulling image "httpd"
  Normal  Pulled                  7m35s  kubelet, k8s-worker02    Successfully pulled image "httpd"
  Normal  Created                 7m34s  kubelet, k8s-worker02    Created container iscsipd-rw
  Normal  Started                 7m34s  kubelet, k8s-worker02    Started container iscsipd-rw
  
 kubectl get pod -o wide
iscsipd                                      1/1     Running             0          9m31s   10.255.2.9     k8s-worker02   <none>           <none>

在k8s-worker02查看挂载情况

[root@k8s-worker02 ~]# lsscsi 
[2:0:0:0]    disk    ATA      QEMU HARDDISK    3     /dev/sda 
[8:0:0:0]    storage IET      Controller       0001  -        
[8:0:0:1]    disk    IET      VIRTUAL-DISK     0001  /dev/sdb 

# lsblk 
NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda               8:0    0   200G  0 disk 
├─sda1            8:1    0     1G  0 part /boot
└─sda2            8:2    0 153.9G  0 part 
  ├─centos-root 253:0    0   150G  0 lvm  /
  └─centos-swap 253:1    0   3.9G  0 lvm  
sdb               8:16   0     1G  0 disk /var/lib/kubelet/pods/c1fee497-392f-4a9e-b9ab-cc49d3cb2538/volumes/kubernetes.io~iscsi/iscsipd-rw

df -hT | grep iscsi
/dev/sdb                ext4      976M  2.6M  958M    1% /var/lib/kubelet/pods/c1fee497-392f-4a9e-b9ab-cc49d3cb2538/volumes/kubernetes.io~iscsi/iscsipd-rw

进入pod

# kubectl exec -it iscsipd bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl kubectl exec [POD] -- [COMMAND] instead.
root@iscsipd:/usr/local/apache2# 
root@iscsipd:/usr/local/apache2# 
root@iscsipd:/usr/local/apache2# ls
bin  build  cgi-bin  conf  error  htdocs  icons  include  logs  modules
root@iscsipd:/usr/local/apache2# ls /
bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@iscsipd:/usr/local/apache2# lsblk
NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda               8:0    0   200G  0 disk 
|-sda1            8:1    0     1G  0 part 
`-sda2            8:2    0 153.9G  0 part 
  |-centos-root 253:0    0   150G  0 lvm  /etc/hosts
  `-centos-swap 253:1    0   3.9G  0 lvm  
sdb               8:16   0     1G  0 disk /mnt
root@iscsipd:/usr/local/apache2# cd /mnt
root@iscsipd:/mnt# echo "wangjinxiong" >> wangjinxiong.txt 
root@iscsipd:/mnt# cat wangjinxiong.txt 
wangjinxiong

https://github.com/kubernetes/examples/tree/master/volumes/iscsi