Use of ssh-agent

The problem with using ssh-agent today is that I have an ssh code gerrit machine on the qa machine and I need to enter passphrase.
Passphrase is required without entering the password, indicating that the trust relationship has been established,
But the key is not added to the ssh-agent. How does www.2cto.com Add the key to the ssh-agent every time the shell is started?

You can add it to/etc/profile. d. However, you still need to enter
One passphrase.

You only need to set an empty passpharse. Ssh-agent also has a proxy forwarding function that can be used in multiple consecutive ssh
The previous ssh-agent does not have to save the private key in multiple places. Reference: http://www.bkjia.com/ OS /201303/195006.html