guix/etc/git/pre-push

#!/bin/sh

# This hook script prevents the user from pushing to Savannah if any of the new
# commits' OpenPGP signatures cannot be verified, or if a commit is signed
# with an unauthorized key.

# Called by "git push" after it has checked the remote status, but before
# anything has been pushed.  If this script exits with a non-zero status nothing
# will be pushed.
#
# This hook is called with the following parameters:
#
# $1 -- Name of the remote to which the push is being done
# $2 -- URL to which the push is being done
#
# If pushing without using a named remote those arguments will be equal.
#
# Information about the commits which are being pushed is supplied as lines to
# the standard input in the form:
#
#   <local ref> <local sha1> <remote ref> <remote sha1>

# This is the "empty hash" used by Git when pushing a branch deletion.
z40=0000000000000000000000000000000000000000

while read local_ref local_hash remote_ref remote_hash
do
	# When deleting a remote branch, no commits are pushed to the remote, and
	# thus there are no signatures to be verified.
	if [ "$local_hash" != $z40 ]
	then
		# Only use the hook when pushing to Savannah.
		case "$2" in
		    *.gnu.org*)
			exec make authenticate check-channel-news
			exit 127
			;;
		    *)
			exit 0
			;;
		esac
	fi
done

exit 0