How to remove the previous version app folder when update(-Uvh) the RPM package(version number modified)? - rpmbuild

Question

#define program installation destination
%define app_destination /opt
%define app_name MY_APP_NAME
%define app_version 2.1
%define app_release 7%{?dist}
%define app_dir %{app_name}-%{app_version}
%define compress_file %{app_dir}.tar.gz
%define app_service_softlink /etc/init.d/%{app_name}
%define app_dir_softlink %{app_destination}/%{app_name}
Name: %{app_name}
Version: %{app_version}
Release: %{app_release}
Summary: MY APP ONE-SENTENCE SUMMARY %{app_version}
# An open source software license
License: GPLv3+
URL: http://www.starscriber.com/
Source0: http://ftp.gnu.org/gnu/%{compress_file}
%description
MY APP DESCRIPTION
%pre
#each time before install/upgrade RPM, check and remove the softlinks provided below
echo "pre..."
if [ -L %{app_service_softlink} ];then
rm %{app_service_softlink}
elif [ -f %{app_service_softlink} ];then
rm %{app_service_softlink}
fi
if [ -L %{app_dir_softlink} ]; then
rm %{app_dir_softlink}
elif [ -d %{app_dir_softlink} ]; then
rmdir %{app_dir_softlink}
fi
%prep
%setup -q
echo "prep..."
# Script commands to "build" the program (e.g. to compile it) and
# get it ready for installing. The program should come with
# instructions on how to do this.
%build
%install
echo "install..."
# uses relative paths
# creates buildroot/destination directory
mkdir -p %{buildroot}%{app_destination}
# copies tar.gz file from source directory to buildroot/destination directory
cp %{_sourcedir}/%{compress_file} %{buildroot}%{app_destination}
# changes directory to buildroot/destination
cd %{buildroot}%{app_destination}
# extracts compression file
tar xf %{compress_file}
# removes the compression file
rm -rf %{compress_file}
cd %{buildroot}%{app_destination}
#invoked after %post when RPM pkg is removal or upgrade
%preun
echo "preun..."
#leftover cleanup
#invoked after %preun when RPM pkg is removal or upgrade
%postun
echo "postun..."
if [ "$1" == "0" ]; then
rm -rf %{app_destination}/%{app_dir}
fi
if [ ! -d %{app_destination}/%{app_dir} ]; then
if [ -L %{app_service_softlink} ]; then
rm %{app_service_softlink}
elif [ -f %{app_service_softlink} ]; then
rm %{app_service_softlink}
fi
if [ -L %{app_dir_softlink} ]; then
rm %{app_dir_softlink}
elif [ -d %{app_dir_softlink} ]; then
rmdir %{app_dir_softlink}
fi
fi
%files
#all files under the provided folder will be gathered up to create RPM pkg
%{app_destination}/%{app_dir}/bin
%{app_destination}/%{app_dir}/conf
%{app_destination}/%{app_dir}/misc
%post
echo "post"
#symbolic link to the new appdir with version
echo "builds new symbolic link for the app folder"
ln -sf %{app_destination}/%{app_dir} %{app_dir_softlink}
echo "builds new symbolic link for the app service"
# make a symbolic for the service file using the new created softlink
ln -sf %{app_destination}/%{app_name}/misc/%{app_name} %{app_service_softlink}
I am trying to create my own RPM package, and here's the SPEC file, it works properly when install(rpm -ivh app-2.1-6.el6.x86_64.rpm), or upgrade(rpm -Uvh app-2.1-7.el6.x86_64.rpm) or remove (rpm -e app-2.1-7.el6.x86_64.rpm)
For RPM package app-2.1-7.el6.x86_64.rpm, the version is 2.1 and release number is 7.
My question is, no matter how I modify the release number, install/upgrade/remove are working properly, but if I modify the version number to 2.2 or 3.2, the previous version folder(/opt/app-2.1) will not be deleted, can anyone help me, how should I delete the previous version folder(/opt/app-2.1) when I update(-Uvh) the RPM package?

Answer 1

The problem is that your package doesn't "own"
the directory /opt/2.1 directory.
Just like tar, rpm will create all "missing" directories
in order to install content on a path.
But on erase, rpm will only remove directories that are
mentioned explicitly in the %files manifest.
Short answer:
If you want rpm --erase to remove a directory path,
the mention in %files.
Shorter anser:
Add
%dir /opt/app-%{version}
to %files. If the directory is empty (i.e. all other files
in /opt/app-%{version} are "owned" and can be removed), the
the "owned /opt/app=%{version} will be removed as well.