git-ssh-signing.sh

# you must also upload the public key as signing key to https://github.com/settings/keys
git config --global user.signingkey '~/.ssh/id_rsa'
git config --global commit.gpgsign true
git config --global gpg.format ssh
# (optional) this file enables `git log --show-signature` and contains email addresses associated with public keys
git config --global gpg.ssh.allowedsignersfile '~/.ssh/git-signers'