1. Check if ssh is installed
rpm -qa | grep ssh
2. Install openssh-server
yum install openssh-server
3. Start the ssh service
systemctl start sshd.service
4. Test if the service is started
ssh
5. Modify the /etc/hosts file
Add the lines after: ip address and hostname.
For example: ip address master
6. Modify the /etc/sysconfig/network file
Add the following two lines after:
NETWORKING=yes
HOSTNAME=master
7. Modify the /etc/hostname file
Modify the name of the machine: for example master
8. Use the hadoop user to perform operations to generate rsa encrypted strings
ssh-keygen -t rsa -P ''
cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
chmod 600 /root/.ssh/authorized_keys
9. Append id_rsa.pub to the authorized key
cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
10. Modify the permissions of the authorization key (note: this step is essential)
chmod 600 /root/.ssh/authorized_keys
11. Use the root user to modify the /etc/ssh/sshd_config file to comment the following three lines
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile.ssh/authorized_keys
12. Switch to hadoop user, test single-machine ssh password-free login, press the prompt to enter yes for the first time, and no prompt will be prompted the next time you log in
ssh master
If it appears: Last login: Thu Mar 10 10:26:52 2016 from master, it means that the single-machine ssh has been successfully configured
13. Configure ssh remote other servers:
1. Copy id_rsa.pub to the remote server .ssh folder and change the name to the corresponding server name.pub
For example: copy from ip address to ip address 2 directory:
scp /root/.ssh/id_rsa.pub root@ip address 2:/root/.ssh/master.pub
2. Copy the copied id_rsa.pub
For example: copy the ip address to the master.pub file of ip address 2 and append it to authorized_keys
cat /root/.ssh/master.pub >> /root/.ssh/authorized_keys
3. SSH remote other server password-free login test:
For example: from master to slave2
ssh hadoop02@slave2
Appears: Last login: Thu Mar 10 13:19:24 2016 from master indicates successful configuration