Add inst.rngd cmdline option

rngd should no long be needed, recent kernels have enough entropy out of
the box. This leaves it in the boot.iso but only enables it if inst.rngd
is passed on the kernel cmdline.

Resolves: rhbz#2028720

80-rhel/config_files/common/inst.rngd.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Hardware RNG Entropy Gatherer Daemon
+ConditionVirtualization=!container
+ConditionKernelCommandLine=|inst.rngd
+ConditionKernelCommandLine=!inst.rngd=0
+
+# The "-f" option is required for the systemd service rngd to work with Type=simple
+[Service]
+Type=simple
+EnvironmentFile=/etc/sysconfig/rngd
+ExecStart=/usr/sbin/rngd -f $RNGD_ARGS

80-rhel/runtime-postinstall.tmpl

@@ -28,10 +28,6 @@ symlink /lib/systemd/system/anaconda.target etc/systemd/system/default.target
 mkdir etc/systemd/system/local-fs.target.wants/
 symlink /lib/systemd/system/tmp.mount etc/systemd/system/local-fs.target.wants/tmp.mount
 
-## Start rngd
-mkdir etc/systemd/system/basic.target.wants/
-symlink /lib/systemd/system/rngd.service etc/systemd/system/basic.target.wants/rngd.service
-
 ## Disable unwanted systemd services
 systemctl disable systemd-readahead-collect.service \
                   systemd-readahead-replay.service \
@@ -46,6 +42,7 @@ systemctl mask fedora-configure.service fedora-loadmodules.service \
                fedora-wait-storage.service media.mount \
                systemd-tmpfiles-clean.service systemd-tmpfiles-clean.timer \
                ldconfig.service
+remove usr/lib/systemd/system/rngd.service
 
 ## remove because it cannot be disabled
 remove usr/lib/systemd/system-generators/lvm2-activation-generator
@@ -83,6 +80,11 @@ install ${configdir}/pam.sshd etc/pam.d/sshd
 install ${configdir}/pam.sshd etc/pam.d/login
 install ${configdir}/pam.sshd etc/pam.d/remote
 
+## set up inst.rngd support
+install ${configdir}/inst.rngd.service etc/systemd/system/inst.rngd.service
+mkdir etc/systemd/system/basic.target.wants/
+symlink /etc/systemd/system/inst.rngd.service etc/systemd/system/basic.target.wants/inst.rngd.service
+
 ## set up "install" user account
 append etc/passwd "install:x:0:0:root:/root:/usr/libexec/anaconda/run-anaconda"
 append etc/shadow "install::14438:0:99999:7:::"