Enabling git-GPG signed commits on MacOS

Install gpg via Homebrew.

brew install gnupg

Here you can generate keys yourself or import an existing key.

gpg --generate-key
// OR
gpg --import path/to/secret.asc

Now we tell git what key we want to use. Run this command to list your keys:

gpg --list-secret-keys --keyid-format=long

You should see some output like below, copy the highlighted section:

sec   rsa2048/9A9A9A9A9A9A9A9A 2015-05-01 [SC]

Then set it as user.signingkey in git config

git config --global user.signingkey 9A9A9A9A9A9A9A9A

Tell git to sign commits and which program to use

git config --global commit.gpgsign true 
git config --global gpg.program gpg

In your bash profile set the following to allow for passphrase entry:

export GPG_TTY=$(tty)

Alternatively you can use the pinentry tool from homebrew.

Thats it! From now on, any new commits will be automatically signed. The program might ask you for your passphrase through your mechanism of choice (terminal/pop up etc).