!2 add zram-generator source package and spec file

From: @duyiwei7w 
Reviewed-by: @yangzhao_kl 
Signed-off-by: @yangzhao_kl

rust-zram-generator.spec

@@ -0,0 +1,100 @@
+%define debug_package %{nil}
+%global crate zram-generator
+
+Name:         rust-%{crate}
+Version:      0.3.2
+Release:      1
+Summary:      Systemd unit generator for zram swap devices
+
+License:        MIT
+URL:            https://crates.io/crates/zram-generator
+Source:         %{crate}-%{version}.crate
+Source1:        zram-generator.conf
+Source2:        zram-generator-vendor.tar.gz
+
+BuildRequires:  rust-packaging rubygem-ronn
+
+%global _description %{expand:
+This is a systemd unit generator that enables swap on zram.
+(With zram, there is no physical swap device. Part of the avaialable RAM
+is used to store compressed pages, essentially trading CPU cycles for memory.)
+}
+
+%description %{_description}
+
+%package     -n %{crate}
+Summary:     %{summary}
+Recommends:  /usr/bin/zramctl
+
+%description -n %{crate} %{_description}
+
+%package     -n %{crate}-defaults
+Summary:        Default configuration for %{crate}
+Requires:       %{crate} = %{version}-%{release}
+Obsoletes:      zram < 0.4-2
+BuildArch:      noarch
+
+%description -n %{crate}-defaults
+%{summary}.
+
+%package        devel
+Summary:        %{summary}
+
+%description    devel %{_description}
+This package contains library source intended for building other packages
+which use "%{crate}" crate.
+
+%prep
+%autosetup -n %{crate}-%{version} -p1
+cp -a %{S:1} .
+tar zxvf %{SOURCE2}
+%cargo_prep
+
+mkdir -p .cargo
+cat >.cargo/config << EOF
+
+[source.crates-io]
+replace-with = "vendored-sources"
+
+[source.vendored-sources]
+directory = "vendor"
+EOF
+
+%build
+export SYSTEMD_UTIL_DIR=%{_systemd_util_dir}
+%cargo_build
+make systemd_service SYSTEMD_SYSTEM_UNIT_DIR=%{?_unitdir} SYSTEMD_SYSTEM_GENERATOR_DIR=%{?_systemdgeneratordir}
+LC_ALL=C.UTF-8 ronn --roff --organization="zram-generator %{version}" man/*.md
+
+%install
+export SYSTEMD_UTIL_DIR=%{_systemd_util_dir}
+%cargo_install
+
+mkdir -p %{buildroot}%{?_systemdgeneratordir}
+cp -a $PWD/.cargo/bin %{buildroot}/usr/
+mv -v %{buildroot}%{_bindir}/zram-generator %{buildroot}%{?_systemdgeneratordir}/
+install -Dpm0644 -t %{buildroot}%{?_unitdir} units/systemd-zram-setup@.service
+install -Dpm0644 -t %{buildroot}%{_prefix}/lib/systemd %{SOURCE1}
+install -Dpm0644 -t %{buildroot}%{_mandir}/man8 man/zram-generator.8
+install -Dpm0644 -t %{buildroot}%{_mandir}/man5 man/zram-generator.conf.5
+
+%files       -n %{crate}
+%license LICENSE
+%doc zram-generator.conf.example
+%doc README.md
+%{?_systemdgeneratordir}/zram-generator
+%{?_unitdir}/systemd-zram-setup@.service
+%{_mandir}/man8/zram-generator.8*
+%{_mandir}/man5/zram-generator.conf.5*
+
+%files       -n %{crate}-defaults
+%{_prefix}/lib/systemd/zram-generator.conf
+
+%files          devel
+%license LICENSE
+%doc README.md
+%{cargo_registry}/%{crate}-%{version}
+
+%changelog
+* Tue May 10 2022 duyiwei <duyiwei@kylinos.cn> - 0.3.2-1
+- Package init

zram-generator.conf

@@ -0,0 +1,9 @@
+# This config file enables a /dev/zram0 device with the default settings:
+# — size — same as available RAM or 8GB, whichever is less
+# — compression — most likely lzo-rle
+#
+# To disable, uninstall zram-generator-defaults or create empty
+# /etc/systemd/zram-generator.conf file.
+[zram0]
+zram-fraction = 1.0
+max-zram-size = 8192