Automatic Git signing with gpg/GnuPG 2.1.x on OSX/MacOS

.profile

# Set GPG_TTY environment variable
export GPG_TTY=$(tty)

gpg-agent.conf

# Connects gpg-agent to the OSX keychain via the brew-installed
# pinentry program from GPGtools. This is the OSX 'magic sauce',
# allowing the gpg key's passphrase to be stored in the login
# keychain, enabling automatic key signing.
pinentry-program /usr/local/bin/pinentry-mac

gpg.conf

# Uncomment within config (or add this line)
use-agent

setup-gpg

# A quick outline of what must be done to get everything working.

# 1) Install the dependencies.
brew install gnupg pinentry-mac

# 2a) Configure git to use gpg2 and your signing key ID.
git config --global user.signingkey <YOUR-SIGNING-KEY-PUB-ID>
git config --global gpg.program gpg2

# 2b) Configure git to automatically sign commits, merges and interactive rebases
git config --global commit.gpgsign true
git config --global merge.gpgsign true
git config --global rebase.gpgsign true

# 2c) If you're using git-flow(-avh), configure git to automatically sign hotfixes, features and releases
git config --global gitflow.hotfix.finish.gpgsign true
git config --global gitflow.feature.finish.gpgsign true
git config --global gitflow.release.finish.gpgsign true

# 3) Configure the GPG components (see above for relevant examples):
#    ~/.gnupg/gpg.conf
#    ~/.gnupg/gpg-agent.conf

# 4) Configure your shell (see above for example in .profile).
#    ~/.bash_profile | ~/.zshrc

# Don't forget to upload your public key to Github!
# https://github.com/blog/2144-gpg-signature-verification
# Note: There needs to be a three-way match on your email for Github to show
# the commit as 'verified': The commit email, github email, & the email associated with the public key

# Learn about creating a GPG key and the knowledge behind these commands here:
# https://git-scm.com/book/en/v2/Git-Tools-Signing-Your-Work