(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

Perform the following steps on the central control server to set password-free SSH login. After the configuration, the central control server can log on to target servers by using SSH without 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 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 script

When multiple target servers use the same login password, we recommend that you use the following script on the central control server to set password-free SSH login for multiple 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