Load SSH agent on bash (interactive) startup, add default SSH key, enable signing commits

! SSH agent and signing on !Windows!

This is for the gist name only.

.bash_profile

#
# Load SSH agent and add key if it's not running already.
# Source: https://docs.github.com/en/authentication/connecting-to-github-with-ssh/working-with-ssh-key-passphrases#auto-launching-ssh-agent-on-git-for-windows
#
# touch ~/.ssh/allowed_signers
# git config --global gpg.ssh.allowedSignersFile "/c/Users/.../.ssh/allowed_signers"
# echo "$(git config --global --get user.email) namespaces=\"git\" $(cat ~/.ssh/id_rsa.pub)" >> ~/.ssh/allowed_signers
# git log --show-signature
#
# START SSH AGENT ->

SSH_AGENT_ENV=~/.ssh/AGENT_ENV

agent_load_env () { test -f "${SSH_AGENT_ENV}" && . "${SSH_AGENT_ENV}" >| /dev/null ; }

agent_start () {
    (umask 077; ssh-agent >| "${SSH_AGENT_ENV}")
    . "${SSH_AGENT_ENV}" >| /dev/null ;
    # This will set SSH_AUTH_SOCK on Windows for new processes, such as your IDE.
    SETX SSH_AUTH_SOCK $SSH_AUTH_SOCK
}

agent_load_env

# agent_run_state: 0=agent running w/ key; 1=agent w/o key; 2=agent not running
agent_run_state=$(ssh-add -l >| /dev/null 2>&1; echo $?)

if [ ! "$SSH_AUTH_SOCK" ] || [ $agent_run_state = 2 ]; then
    agent_start
    ssh-add -t 1200
elif [ "$SSH_AUTH_SOCK" ] && [ $agent_run_state = 1 ]; then
    ssh-add -t 1200
fi

unset SSH_AGENT_ENV

# <- END SSH AGENT

.gitconfig

[user]
	...
	signingKey = C:/Users/.../.ssh/id_rsa
...
[gpg]
	format = ssh
[gpg "ssh"]
	allowedSignersFile = C:/Users/.../.ssh/allowed_signers
[commit]
	gpgSign = true
...