Use SSH Public Key Authentication

Without use any prompt password, ssh provides a beautiful way to run ssh command.

Create SSH Key pair, i.e., public/private key.
Upload the key pair to server.

Step1. Create SSH Key Pair

If you already have a key pair, you can ignore this step, and use your old pair to continue (Go to next step).

Create a new ssh key pair, just run command:

Terminal

> cd ~/.ssh # go to this directory
> ssh-keygen # create pair

then you need fill all the questions, it looks like: (Here I create a pair named demo_rsa)

Outputs

Generating public/private rsa key pair.
Enter file in which to save the key (/Users/youxingz/.ssh/id_rsa): demo_rsa
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in demo_rsa
Your public key has been saved in demo_rsa.pub
The key fingerprint is:
SHA256:D3hdvNqzxe12wMHFJpxmCipgmG2wbw3Ikz75uO6x/RA youxingz@WarmestolorsMBP
The key's randomart image is:
+---[RSA 3072]----+
|  .=         . o |
| .o+=     ..  * +|
|  *o..   . .o= + |
| . + o.... ...o  |
|  + E o.S . .. . |
|   = . . o o .o. |
|  o o     o o o..|
|   = .       + .o|
| o= ...     .  .o|
+----[SHA256]-----+

Now, you can check your files under this directory (~/.ssh), there are two files named demo_rsa and demo_rsa.pub, corresponding private & public key.

Step2. Upload to server

Terminal

> ssh-copy-id -i demo_rsa [user]@[host]
> # type your password

Then you can run ssh [user]@[host] without any password prompt required.