SSH Configs

When you start to work with multiple remote servers you may run into problems.
This is because your computer does no longer know which ssh-key to provide for which server.
But don't you worry! ssh config to the rescue.
A ssh .ssh/config file can help you to manage multiple ssh-keys and is simply a text file (without .txt extension) where each remote is specified like this:

Host aliases
   HostName hostname
   User username
   IdentityFile .ssh/keyname

• alias is an alias that you may specify i.e. in order to ssh into remote servers.
• hostname is the name of the server i.e. gitlab.ethz.ch
• User is your gitlab username i.e. for gitlab.ethz.ch it is you nethz username.
• IdentityFile is the path to you local private ssh key i.e. .ssh/id_rsa

Creating A config file

1. Change into your home directory: cd
2. Change into your ssh directory: cd .ssh
3. Create a ssh config file: touch config
4. Edit the ssh config file as fit
   Sidenote: when using multiple ssh keys its best to give them descriptive names when creating them i.e. id_rsa_gitlab_ethz

Using Git after setting up a config file

If you provide an alias to a Host in your git config file you need to access this host with the same alias.

Host gitlab_account_1
   HostName gitlab.ethz.ch
   User username
   IdentityFile ~/.ssh/id_rsa_ethz

cloning the repo is then: $ git clone git@gitlab_account_1:pt1_hs20/lecture.git

If you only have one account to a server it is recommended to not give an alias (use the same for Host as for HostName).

Host gitlab.ethz.ch
   HostName gitlab.ethz.ch
   User username
   IdentityFile ~/.ssh/id_rsa_ethz

Cloning the repo is then: $ git clone git@gitlab.ethz.ch:pt1_hs20/lecture.git