Sometimes I write content via a ssh connection, using vi as my editor. In order to deploy new content, it is useful to have ssh-agent running. Ony way to do that is like this:
[nikola] tingo@kg-core2:~/personal/projects/nikola % eval `ssh-agent -c` Agent pid 65221
This command sets the environment variables SSH_AUTH_SOCK and SSH_AGENT_PID, and you are ready to add keys with
ssh-add. When you are finished, you just use
ssh-agent -k to kill the agent.