How to share the same storage among multiple kubernetes clusters

introduction

I thought about a problem at work today ： The project uses a dual cluster deployment Application , But there is only one storage used , And a funny name , It's called “ Multi center shared storage ”. The advantages of this are obvious , One storage realizes the data sharing of multiple clusters , This is easy to understand , Although there are multiple clusters , But the application is the same , Data should be shared . So how is it done ？ Think for a long time , Thought of a solution .

Environmental preparation

1. Server preparation

To prepare the 7 Servers , These servers are in the same network , Can access each other .6 Two servers can be built kubernetes colony （ One master and two slaves ）, There is also one as NFS The primary node of the file system .

2. Resource allocation

k8s colony 1	k8s colony 2	NFS
192.168.0.135	192.168.0.163	192.168.0.185
192.168.0.198	192.168.0.247
192.168.0.12	192.168.0.167

explain ：NFS It's the network file system , Give a single server as server, Other servers are client.

install NFS

1. All nodes execute

yum install -y nfs-utils

2. nfs Master node （192.168.0.185） perform

echo "/nfs/data/ *(insecure,rw,sync,no_root_squash)" > /etc/exports  #  Exposed the directory /nfs/data/,`*` It means that all nodes can access .
mkdir -p /nfs/data
systemctl enable rpcbind --now
systemctl enable nfs-server --now
#  Configuration takes effect 
exportfs -r

#  Check and verify 
[[email protected] ~]# exportfs
/nfs/data      <world>
[[email protected] ~]#

2. nfs Execute... From node

#  Exhibition 192.168.0.185 Which directories can be mounted 
showmount -e 192.168.0.185  # ip Change to your own master node ip

mkdir -p /nfs/data
#  Mount the local directory and remote directory 
mount -t nfs 192.168.0.185:/nfs/data /nfs/data

3. verification

#  Write a test file at any node 
echo "hello nfs server" > /nfs/data/test.txt

By writing a file at any node , You can see the contents of the file in other nodes . In this way kubernetes File sharing of multiple clusters . take NFS The master node is maintained separately , It won't be right kubernetes Clustering impacts .“ Multi center shared storage ” So it was born .