ssh

You may edit ~/.ssh/authorized_keys' manually on a remote host, or use cat ~/.ssh/id_rsa.pub | ssh user@host 'cat >> ~/.ssh/authorized_keys', but there is a command for that: ssh-copy-id (full man page here).

Examples

• Add your ssh public key to remoteuser@remotehost.example.com

    someone@somemachine:~$  ssh-copy-id remoteuser@remotehost.example.com
    /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to  filter out any that are already installed
    /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are  prompted now it is to install the new keys
    remoteuser@remotehost.example.com password: *********
  
    Number of key(s) added: 1
  
    Now try logging into the machine, with:   "ssh remoteuser@remotehost.example.com"
    and check to make sure that only the key(s) you wanted were added.
  
    someone@somemachine:~$
  

  You may have noticed that I put a space before “ssh-copy-id”, here is why : HISTCONTROL variable in bash.

• Add your ssh key with a custom comment:

    someone@somemachine:~$  ssh-copy-id -i my_key_with_a_custom_comment.pub remoteuser@remotehost.example.com
    /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "my_key_with_a_custom_comment.pub"
    /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to  filter out any that are already installed
    /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are  prompted now it is to install the new keys
    remoteuser@remotehost.example.com password: *********
  
    Number of key(s) added: 1
  
    Now try logging into the machine, with:   "ssh remoteuser@remotehost.example.com"
    and check to make sure that only the key(s) you wanted were added.
  
    someone@somemachine:~$
  

• Add your ssh key with a custom comment using another key for authentification this one doesn’t work without the -f flag, which will add the public key even if already present:

    someone@somemachine:~$  ssh-copy-id -f -i my_key_with_a_custom_comment.pub -o "IdentityFile ~/.ssh/id_rsa.old" remoteuser@remotehost.example.com
    /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "my_key_with_a_custom_comment.pub"
    /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to  filter out any that are already installed
    /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are  prompted now it is to install the new keys
    remoteuser@remotehost.example.com password: *********
  
    Number of key(s) added: 1
  
    Now try logging into the machine, with:   "ssh remoteuser@remotehost.example.com"
    and check to make sure that only the key(s) you wanted were added.
  
    someone@somemachine:~$
  

~~~

Question, remark, bug? Don't hesitate to contact me or report a bug.