Here we show a way to build RPMs with Jenkins using a Makefile. Now we will show a Jenkins based build (without create Makefle).

So, you can directly create a new Job in your Jenkins using the Free Style creation method and adding a shell build step. Inside the text area you can put something like this:

testrel=$(/usr/bin/git diff HEAD~1 | awk '/[\t ]*\+[\t ]*Release/ {
print "NEWREL"; exit 0 }')
if [ "$testrel" != "NEWREL" ]; then
    echo "There is no new release in the rpm spec files - do not rebuild."
    exit 0
rm -rf rpmbuild ${JOB_NAME}.tar.gz
tar --exclude-vcs --exclude='rpmbuild' -cp * | (cd
rpmbuild/SOURCES/${JOB_NAME} ; tar xp)
cd ${WORKSPACE}/rpmbuild/SOURCES
tar -cvzf ${JOB_NAME}.tar.gz ${JOB_NAME}
cp misc/specs/*.spec rpmbuild/SPECS/
sed -i "s/^[\t ]*Source0:.*/Source0: ${JOB_NAME}.tar.gz/g" rpmbuild/SPECS/*.spec
sed -i "s/^[\t ]*%setup[\t ]\+-n[\t ]\+.*/%setup -n ${JOB_NAME}/g"
rpmbuild --define "_topdir %(pwd)/rpmbuild" -ba rpmbuild/SPECS/*.spec

The first line of the script checks for git log to find if Release is changed inside the spec file (that should be naturally committed as resources of your project); the project will be built only if you modified the Release inside the spec!

After that the operation is like the one proposed in the Makefile: creation of tar.gz source archive, creation of rpm-build directories, build rpm.

So, you can choose to put your build code completely inside Jenkins or create a Makefile and link your build process with your project (changes in project that requires build process changes won't impact Jenkins configuration.