Add RPM build instructions

Author: mtds

packaging/rpm/README.md

@@ -0,0 +1,44 @@
+## Setup a development environment
+
+In order to build your own RPMs you have to setup your own _development environment_ as explained [here](https://wiki.centos.org/HowTos/SetupRpmBuildEnvironment).
+
+### Quick setup
+
+1. Install the ``rpm-build`` and ``rpmdevtools`` packages.
+
+2. Login as **normal user** and create the following structure in the home directory:
+```bash
+mkdir -p ~/rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
+```
+3. Create the RPM macros file with the following content:
+```bash
+echo "%_topdir $HOME/rpmbuild" > ~/.rpmmacros
+```
+
+### Prepare the build
+ 
+4. Clone this repo:
+```bash
+git clone https://github.com/vpenso/prometheus-slurm-exporter.git
+```
+5. Get into the source directory and copy the following files under ``~/rpmbuild/SOURCES``:
+```bash
+cd prometheus-slurm-exporter
+cp README.md ~/rpmbuild/SOURCES
+cp LICENSE ~/rpmbuild/SOURCES
+cp lib/systemd/prometheus-slurm-exporter.service ~/rpmbuild/SOURCES
+```
+6. Copy the SPEC file in the proper directory:
+```bash
+cd prometheus-slurm-exporter
+cp packaging/rpm/*.spec ~/rpmbuild/SPECS
+```
+
+### Build the RPM package
+
+8. Build the RPM based on your SPEC file:
+```bash
+cd $HOME/rpmbuild/SPECS
+rpmbuild -ba prometheus-slurm-exporter.spec
+```
+9. The RPM package will be placed under $HOME/rpmbuild/RPMS/x86_64