make: Release pipeline

This commit adds new make targets for rpm, deb, and pacman packages.
It also adds a phony target that uploads tarballs of the packages,
along with their signed (and unsigned) checksums to the github release
page. Once the current commit is tagged as a release, run `make release`
to build the packages and upload them to github.

misc/fpm-pack.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+# This script packages rpm, deb, and pacman packages of mgmt with fpm. The
+# first argument is the package type, and all subsequent arguments are the
+# dependencies. Example usage: `./fpm-pack.sh deb dependency1 dependency2`
+
+# the binary to package
+BINARY="mgmt"
+# git tag pointing to the current commit
+TAG=$(git tag -l --points-at HEAD)
+# maintainer email
+MAINTAINER="mgmt@noreply.github.com"
+# project url
+URL="https://github.com/purpleidea/mgmt/"
+# project description
+DESCRIPTION="Next generation distributed, event-driven, parallel config management!"
+# project license
+LICENSE="GPLv3"
+# location to install the binary
+PREFIX="/usr/bin"
+# release directory
+DIR="releases"
+
+# placeholder for dependencies to be read from arguments
+DEPS=
+# placeholder for changelog argument parsed from the package type
+CHANGELOG=
+
+# make sure we're on a tagged commit
+if [ "$TAG" == "" ]; then
+	echo "cannot release an untagged commit"
+	exit 1
+fi
+
+# make sure the package type is valid
+if [ "$1" != "deb" ] && [ "$1" != "rpm" ] && [ "$1" != "pacman" ]; then
+	echo "invalid package type"
+	exit 1
+fi
+
+# there are no changelogs for pacman packages
+if [ "$1" != "pacman" ]; then
+	CHANGELOG="--${1}-changelog=${DIR}/${1}/changelog"
+fi
+
+# arguments after the first one are deps
+for i in "${@:2}"; do
+	DEPS="$DEPS -d $i"
+done
+
+# build the package
+fpm \
+	--log error \
+	--name "$BINARY" \
+	--version "$TAG" \
+	--maintainer "$MAINTAINER" \
+	--url "$URL" \
+	--description "$DESCRIPTION" \
+	--license "$LICENSE" \
+	--input-type dir \
+	--output-type "$1" \
+	--package "${DIR}/${1}/" \
+	${CHANGELOG} \
+	${DEPS} \
+	--prefix "$PREFIX" \
+	"$BINARY"