I have a private key set up for my github account, the passphrase to which is, I believe, stored in OS X's keychain. I certainly don't have to type it in when I open a terminal window and enter
However, when I'm running bash over an ssh session, or locally inside a tmux session, I have to type in the passphrase every single time I attempt to ssh to github.
This question suggests that a similar problem exists with screen, but I don't really understand the issue well enough to fix it in tmux. There's also this page which includes a fairly complicated solution, but for zsh.
In response to @Mikel's answer, from a local terminal I get the following output:
[~] $ echo $SSH_AUTH_SOCK /tmp/launch-S4HBD6/Listeners [~] $ ssh-add -l 2048 [my key fingerprint] /Users/richie/.ssh/id_rsa (RSA) [~] $ typeset -p SSH_AUTH_SOCK declare -x SSH_AUTH_SOCK="/tmp/launch-S4HBD6/Listeners"
Whereas over ssh or in tmux I get:
[~] $ echo $SSH_AUTH_SOCK [~] $ ssh-add -l Could not open a connection to your authentication agent. [~] $ typeset -p SSH_AUTH_SOCK bash: typeset: SSH_AUTH_SOCK: not found
echo $SSH_AGENT_PID returns nothing whatever shell I run it from.