(Optional) Set password-free SSH login

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

Set up password-free SSH login on the control machine by following these steps. After configuration, the control machine will be able to SSH into the target machine without requiring a password.

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 new keys.

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 the public key 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

If the login password of multiple target servers is the same, we recommend that you use the following script on the central control server to configure SSH passwordless login for the target servers.

#!/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