When I'm running Gnome, ssh-agent will run ssh-add upon slogin/ssh if the identity is not loaded. I want to mimic this behavior on remote shells, but everything I find suggests to run ssh-add upon login. I only want to run ssh-add if I subsequently run slogin/ssh on the remote shell, not every time I login.
4 Answers
I worked out a solution for this via the bash shell.
Add to .bashrc:
check-ssh-add() { if [ "$DESKTOP_SESSION" == "" ]; then if [[ `ssh-add -l` != *id_?sa* ]]; then ssh-add -t 5h ## 5 hour ssh-agent expiration fi fi } slogin() { check-ssh-add /usr/bin/slogin $@ } ssh() { check-ssh-add /usr/bin/ssh $@ } scp() { check-ssh-add /usr/bin/scp $@ } sftp() { check-ssh-add /usr/bin/sftp $@ } There's actually an even simpler way. ssh-add -l returns true (0) if there are keys and false (1) otherwise, so your first function can be replaced with this:
check-ssh-add() { if ! ssh-add -l >/dev/null; then ssh-add -t 5h fi } Even simpler in the «this is an interactive session» part add
ssh-add -l &> /dev/null || ssh-add ~/.ssh/my_id Newer versions of OpenSSH can add the key to the agent on first use, if you enable AddKeysToAgent yes in your ~/.ssh/config.
(I've learned this from . I'm not sure what the proper StackOverflow etiquette is for coping answers across various StackExchange sites.)
