scripts: introduce a wrapper to locally build deb package (#490)

This change introduces a shell script to wrap the steps to locally
build a deb package based on our debian packaging.

The user must provide VERSION and RELEASE environment variable to
be passed in to deb builder.

build-deb.sh

@@ -0,0 +1,47 @@
+#!/bin/env bash
+#
+# This script wraps the steps required to locally build a deb package
+# based on the in tree debian packaging (see invocation example bellow).
+#
+# After the build is finished the script will print out where the final
+# artifact was generated.
+#
+# Invocation:
+# VERSION=<version> RELEASE=<release> ./build-deb.sh
+#
+
+BUILD_DIR=$(mktemp -d)
+PKGNAME="google-guest-agent"
+
+if [ -z "${VERSION}" ]; then
+   echo "VERSION environment variable is not set"
+   exit 1
+fi
+
+if [ -z "${RELEASE}" ]; then
+   echo "RELEASE environment variable is not set"
+   exit 1
+fi
+
+TARBALL="${PKGNAME}_${VERSION}.orig.tar.gz"
+
+echo "Creating tarball: ${TARBALL}"
+tar czvf "${BUILD_DIR}/${TARBALL}" --exclude .git --exclude packaging \
+  --transform "s/^\./${PKGNAME}-${VERSION}/" .
+
+tar -C "$BUILD_DIR" -xzvf "${BUILD_DIR}/${TARBALL}"
+PKGDIR="${BUILD_DIR}/${PKGNAME}-${VERSION}"
+
+cp -r packaging/debian "${BUILD_DIR}/${PKGNAME}-${VERSION}/"
+
+cd "${BUILD_DIR}/${PKGNAME}-${VERSION}"
+
+# We generate this to enable auto-versioning.
+[[ -f debian/changelog ]] && rm debian/changelog
+
+dch --create -M -v 1:${VERSION}-${RELEASE} --package $PKGNAME -D stable \
+  "Debian packaging for ${PKGNAME}"
+
+DEB_BUILD_OPTIONS="noautodbgsym nocheck" debuild -e "VERSION=${VERSION}" -e "RELEASE=${RELEASE}" -us -uc
+
+echo "Package built at: ${BUILD_DIR}"