(Optional) Set password-free SSH logon

This topic describes how to enable password-free SSH logon.

Terms

• Central control server

  The server where obd is installed. This server is used for managing the OceanBase cluster and storing the installation packages and configuration information of the OceanBase cluster.

• Target server

  The server where OceanBase Database is installed..

Procedure

To set password-free SSH logon, follow these steps:

1. Run the following command on the central control server to check whether the key exists:

   [admin@test001 ~]$ ls ~/.ssh/id_rsa.pub
   

   If yes, you do not need to generate a new private SSH key.

2. (Optional) Run the following command on the central control server to generate public and private SSH keys:

   [admin@test001 ~]$ ssh-keygen -t rsa
   

3. Copy and paste the public keys to the authorized_keys file on the target server:

   [admin@test001 ~]$ ssh-copy-id -i ~/.ssh/id_rsa.pub <user>@<server_ip>
   

Appendix: sample scripts

We recommend that you use the following script. To run this script, you must have the sudo privilege.

#!/usr/bin/bash
   
SERVERS=("<user>@<server_ip1>" "<user>@<server_ip2>" "<user>@<server_ip3>")
PASSWORD="******"
keygen() {
sudo yum -y install expect
expect -c "
   spawn ssh-keygen -t rsa
   expect {
      *(~/.ssh/id_rsa):* { send -- \r;exp_continue}
      *(y/n)* { send -- y\r;exp_continue}
      *Enter* { send -- \r;exp_continue}
      *(y/n)* { send -- y\r;exp_continue}
      *Enter* { send -- \r;exp_continue}
      eof {exit 0}
   }
   expect eof
"
}
copy(){
expect -c "
   set timeout -1
   spawn ssh-copy-id $1
   expect {
      *(yes/no)* { send -- yes\r; exp_continue }
      *password:* { send -- $PASSWORD\r; exp_continue}
      eof {exit 0}
   }
   expect eof
"
}
ssh_copy_id_to_all(){
keygen ;
for host in ${SERVERS[@]}
do
      copy $host
done
}
ssh_copy_id_to_all