Building RPMs for RHEL6 or CentOS6

In this post I will build a very simple RPM, this RPM will contain a very useful program/shell script. With this information you can build complex RPMs later on.

Set up your build environment

In this case I am using a RHEL 6.5 64bit system

[root@rpmbuild ~]# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 6.5 (Santiago) 

Install the tools: rpm-build: is what you need to build RPMs rpmdevtools: is not required but it is very helpful because it helps you create the directory tree and base SPEC file

[root@rpmbuild ~]# yum install rpm-build rpmdevtools

Create a non-privileged user to build the RPMs

[root@rpmbuild ~]# useradd rpmbuilder
[root@rpmbuild ~]# su - rpmbuilder
[rpmbuilder@rpmbuild ~]$

Create the directory tree using rpmdev-setuptree

[rpmbuilder@rpmbuild ~]$ rpmdev-setuptree
[rpmbuilder@rpmbuild ~]$ tree rpmbuild/
rpmbuild/
├── BUILD
├── RPMS
├── SOURCES
├── SPECS
└── SRPMS

Package Application

Work on packaging your application/program (e.g. very_useful_script.sh) The folder and the archive naming is important for later when they get unarchived, the rpm tools will by default use name-version (e.g. name=very-useful-script, version=1.0, that is why the folder/archive was named very-useful-script-1.0/ ). That is the default and can be easily changed in the SPEC file.

[rpmbuilde@rpmbuild ~]$ ls
rpmbuild very_useful_script.sh
[rpmbuilde@rpmbuild ~]$ mkdir very-useful-script-1.0
[rpmbuilde@rpmbuild ~]$ mv very_useful_script.sh very-useful-script-1.0/
[rpmbuilde@rpmbuild ~]$ tar cvzf very-useful-script-1.0.tgz very-useful-script-1.0/
[rpmbuilde@rpmbuild ~]$ ls
rpmbuild  very-useful-script-1.0  very_useful_script.sh  very-useful-script-1.0.tgz

Move your packaged application to the SOURCES directory under rpmbuild/

[rpmbuilde@rpmbuild ~]$ mv very-useful-script-1.0.tgz ~/rpmbuild/SOURCES/

Now it is time to create the SPEC

Create a skeleton spec file

[rpmbuilde@rpmbuild ~]$ rpmdev-newspec 
Skeleton specfile (minimal) has been created to "newpackage.spec".

Move it to your directory tree

[rpmbuilde@rpmbuild ~]$ mv newpackage.spec ~/rpmbuild/SPECS/very-useful-script.spec

This is how your directory tree should look like

[rpmbuilde@rpmbuild ~]$ tree rpmbuild/
rpmbuild/
├── BUILD
├── RPMS
├── SOURCES
│   └── very-useful-script.tgz
├── SPECS
│   └── very-useful-script.spec
└── SRPMS

5 directories, 2 files

SPEC file:

Name:           very-useful-script
Version:        1.0
Release:        1%{?dist}
Summary:        This is a very useful script
Group:          Applications/System
License:        MIT
URL:            http://example.com
Source:         very-useful-script-1.0.tgz

%description
This is a very useful script

%prep
%setup -q

%install
rm -rf $RPM_BUILD_ROOT
install -d $RPM_BUILD_ROOT/usr/local/bin/
install -m 755 very_useful_script.sh $RPM_BUILD_ROOT/usr/local/bin/very_useful_script.sh

%clean
rm -rf $RPM_BUILD_ROOT

%files
%dir /usr/local/bin
%defattr(-,root,root,-)
%doc
/usr/local/bin/very_useful_script.sh

%changelog

Dissecting the SPEC file The below is header information and just descriptive data

Name:           very-useful-script           
Version:        1.0
Release:        1%{?dist}
Summary:        This is a very useful script
Group:          Applications/System
License:        MIT 
URL:            http://example.com
Source:         very-useful-script-1.0.tgz

%description
This is a very useful script

The below is where we prepare our sources to be packaged into RPM %prep is a section where we can execute commands or use macros. %setup is a macro that unarchives the original sources. Earlier I was discussing the importance of naming the folder and archive as name-version, this is because the %setup macro expects that by default, but you can overwrite the default by specifying the folder name (e.g. %setup -q -n very-useful-script-1.0-john-x86)

%prep
%setup -q 

OR

%prep
%setup -q -n very-useful-script-1.0-john-x86

The below removes previous remains of the files in the buildroot Then creates a folder /usr/local/bin/ in the buildroot Then puts our very_useful_script.sh in /usr/loca/bin with mode 755

%install
rm -rf $RPM_BUILD_ROOT
install -d $RPM_BUILD_ROOT/usr/local/bin/
install -m 755 very_useful_script.sh $RPM_BUILD_ROOT/usr/local/bin/very_useful_script.sh

The below just cleans the buildroot

%clean
rm -rf $RPM_BUILD_ROOT

The below specifies all the files that will be installed by the RPM You need to list them all, or use wildcards

%files
%dir /usr/local/bin
%defattr(-,root,root,-)
%doc
/usr/local/bin/very_useful_script.sh

Build the RPM using the SPEC file

[rpmbuilde@rpmbuild rpmbuild]$ rpmbuild -ba ~/rpmbuild/SPECS/very-useful-script.spec 

After the RPM has been successfully been built, you can find it under:

[root@rpmbuild ~]# ls /home/rpmbuilde/rpmbuild/RPMS/x86_64/

Install it (need to be root)

[root@rpmbuild ~]# rpm -ivh /home/rpmbuilde/rpmbuild/RPMS/x86_64/very-useful-script-1.0-1.el6.x86_64.rpm

Hopefully this guide will help you when building RPMs.