Create an RPM that can also manipulate files and add users

Question

I'm trying to create an RPM in Fedora 15 that will install my software, but in order for my software to work correctly once installed, I also need to edit other (configuration) files on the system, add users/groups, etc. Performing some of these tasks is only allowed by the root user. I know to never create an RPM as the root user, and I understand why that is such a bad idea. However, if I add shell script statements to my spec file (%post, %prep... any section) to edit the necessary files, add users/groups, etc., my rpmbuild command fails with message "Permission denied" (not surprisingly).

What's the best way to handle this? Do I have to tell my users to install my package first, and then perhaps run a shell script as root to configure it all? That doesn't seem very elegant. I was hoping to allow a user to do everything with one simple command such as 'yum install mysoftware'.

Much of my research suggests that perhaps this shouldn't even be done via RPM. I've read many parts of Maximum RPM, and lots of other good resources, but haven't found what I'm looking for. I'm new to creating RPMs, but have already been able to successfully create a simple spec file for my software... I just can't get everything configured properly after the package is unzipped and installed to the correct location. Any input is greatly appreciated!

Answer 1

useradd should be run in %pre and shouldn't run during rpmbuild. That's the standard way of doing it. I would recommend the packaging guidelines and specifically the section on users and groups.

Answer 2

The %pre section of your RPM .spec file should check for all the conditions necessary for your software to install.
The %post section of your RPM .spec file should make all the modifications needed for your software to run.
To avoid file permission errors in the %post section of your RPM .spec file, you can set the file permissions and ownership in the %files section. That way, the user who installs the RPM has the appropriate permissions to modify the configuration files.

%install
# Copy files to directories on your installation server

%files
# Set file permissions and ownership on your installation server
%attr(775, myuser, mygroup) /path/to/my/file


%pre
# Check if custom user 'myuser' exists. If not, create it.
# Check if custom group 'mygroup' exists. If not, create it.
# All other checks here

%post
# Perform post-installation steps here, like editing other (configuration) files.
echo "Installation complete."