I’ve been completely curious on how to actually build an RPM for Redhat/Centos from since…well, I knew they existed. There are many articles out there on the interwebs, but I felt it necessary to dig on out and get it going from conception to death.
Virtual Hardware and Software:
To start, i’m gonna use Oracle VM Virtualbox (currently at 5.0.26 r108824) and a Centos 6.8 Minimal install. What better way to start this than from nothing.
I created the VM with 1GB of RAM and the standard 8GB Virtual Hard Drive. Made some minor modifications to the VM such as:
- Disabled the Audio
- Enabled NIC1 and bridged it to my Ethernet Adapter
- Disabled the USB Controller
I mounted the ISO and booted it up for the install.
Operating System Installation:
Clicking Start >, I skipped media testing and sailed into Anaconda. I accepted all default options except for allowing my Network Interface to be configured On and DHCP enabled. This saves me configuration options later on for /etc/sysconfig/networking-scripts and /etc/resolv.conf. Made roots password, well, password, since i’ll be sudo’ing a user for good measure. 205 packages later I have my system ready to be SSH’d into.
First Boot:
Once everything was installed and configured from Anaconda there was a bit of cleanup I like to do. It’s not required on every installation, but it helps me do things in my development environments without issues later on.
More updates:
At the time of this writing, with a fresh ISO you still need to belt out a yum upgrade. There exists 1 package to install, 27 to upgrade, and 76M of data to download. Best to get this out of the way before changing system configurations and having them reset back to basics. shutdown -r now, and we’re back in business.
Disabling selinux:
Fairly easy to do, and there is a plethora of documents on the interwebs to do it. All done as root:
vi /etc/selinux/config SELINUX=permissive
Firing the firewall:
Cleanly shutting off iptables just helps in debugging local and remote connection issues. Good thing we won’t come into this with making our RPMs, but I might want to use this development machine later on and I don’t want to have to assume I did it when debugging issues. All done as root:
service iptables save service iptables stop chkconfig iptables off
Making myself useful:
Still have to do the basic administration, and create my user and give it some god-like sudo permissions:
adduser mheick passwd mheick visudo mheick ALL=(ALL) ALL
Finally, we do some minor shell-related things like setting our TERM=xterm-256color and finding out our ip address so we can SSH into it to get this party started.
Finding and following instructions:
So, we need a couple things that do not come with the minimum install to prepare for this journey:
1 – We need a user that we will /use/ to build things with. We’re gonna create one called builder:
sudo adduser robertbuilder sudo passwd robertbuilder
2 – We are going to need rpm-build, devtools and their dependencies:
sudo yum install rpm-build rpmdevrools
Our data:
We’re gonna be a good sport and create some test data, and go ahead and tar it up:
mkdir data chdir data touch main touch final touch one tar -czf myfirstrpm.tar.gz
This creates myfirstrpm.tar.gz, which we will use to extract these junky files somewhere.
Before making a .spec file, we must be prepared:
The heart and soul of an RPM is this specific file. It contains all the instructions on /what/ to do with the contents of the RPM, where to install things, what to say, etc. We’re going to start off getting our RPM over in robertbuilder‘s home folder, passing along ownership, and then becoming robertbuilder to continue on.
sudo cp myfirstrpm.tar.gz /home/robertbuilder/ sudo chown robertbuilder:robertbuilder /home/robertbuilder/myfirstrpm.tar.gz sudo su robertbuilder
Our builder user needs a folder structure in order to store our files, test out our RPMs, store our other files, and do testing and funsies. We use what we’re given.
rpmdev-setuptree
This creates the ~/rpmbuild/(BUILD|RPMS|SOURCES|SPECS|SRPMS) folders so that we can actually make this build happen.
Getting the .spec into it
We need to hope into the ~/rpmbuild/SPECS folder and execute our spec-template creator
rpmdev-newspec myfirstrpm
This creates a basic .spec:
Name: myfirstrpm
Version:
Release: 1%{?dist}
Summary:
Group:
License:
URL:
Source0:
BuildRequires:
Requires:
%description
%prep
%setup -q
%build
%configure
make %{?_smp_mflags}
%install
rm -rf $RPM_BUILD_ROOT
make install DESTDIR=$RPM_BUILD_ROOT
%clean
rm -rf $RPM_BUILD_ROOT
%files
%defattr(-,root,root,-)
%doc
%changelog
We’re going to modify lines in that so that we can properly install our myfirstrpm.tar.gz
Now, we need HAAAALP!:
No worries. We have centos.org documentation!