(Optional) Set up passwordless SSH login

Terms

• Central control machine

  The machine where OBD is installed. It is used to manage the OceanBase cluster, store the OceanBase cluster installation packages, and the cluster configuration information.

• Target machine

  The machine where OceanBase Database is installed.

Procedure

Follow these steps on the central control machine to set up passwordless SSH login. After configuration, you can log in to the target machine from the central control machine without a password.

1. Run the following command on the central control machine to check if a key exists:

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

   If the result shows that a key already exists, there is no need to generate a new one.

2. (Optional) Run the following command on the central control machine to generate an SSH public and private key:

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

3. Copy the public key from the central control machine to the authorized_keys file on the target machine:

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

(Appendix) Script reference

When multiple target machines use the same login password, it is recommended that you use the following script on the central control machine to configure SSH passwordless login for multiple target machines.

#!/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