Allow install disk overwrite from cmdline

Add rd.kiwi.oem.installdevice=DEVICE. Configures the disk device
that should be used in an OEM installation. This overwrites any
other oem device setting, e.g device filter or maxdisk and just
continues the installation on the given device. However, the
device must exist and must be a block special.

doc/source/concept_and_workflow/customize_the_boot_process.rst

@@ -210,6 +210,12 @@ the available kernel boot parameters for this modules:
   OS deployment is `/dev/sdj`. With `rd.kiwi.oem.maxdisk=500G` the
   deployment will land on that RAID disk.
 
+``rd.kiwi.oem.installdevice``
+  Configures the disk device that should be used in an OEM
+  installation. This overwrites any other oem device setting, e.g device
+  filter or maxdisk and just continues the installation on the given
+  device. However, the device must exist and must be a block special.
+
 ``rd.live.overlay.size``
   Tells a live ISO image the size for the `tmpfs` filesystem that is used
   for the `overlayfs` mount process. If the write area of the overlayfs

dracut/modules.d/90kiwi-dump/kiwi-dump-image.sh

@@ -38,6 +38,7 @@ function get_disk_list {
     max_disk=0
     kiwi_oemmultipath_scan=$(bool "${kiwi_oemmultipath_scan}")
     kiwi_oem_maxdisk=$(getarg rd.kiwi.oem.maxdisk=)
+    kiwi_oem_installdevice=$(getarg rd.kiwi.oem.installdevice=)
     if [ -n "${kiwi_oem_maxdisk}" ]; then
         max_disk=$(binsize_to_bytesize "${kiwi_oem_maxdisk}") || max_disk=0
     fi
@@ -107,6 +108,26 @@ function get_disk_list {
         fi
         list_items="${list_items} ${disk_device} ${disk_size}"
     done
+    if [ -n "${kiwi_oem_installdevice}" ];then
+        # install device overwritten by cmdline.
+        local device=${kiwi_oem_installdevice}
+        local device_meta
+        local device_size
+        if [ ! -e "${device}" ];then
+            local no_dev="Given device ${device} does not exist"
+            report_and_quit "${no_dev}"
+        fi
+        if [ ! -b "${device}" ];then
+            local no_block_dev="Given device ${device} is not a block special"
+            report_and_quit "${no_block_dev}"
+        fi
+        device_meta=$(
+            eval lsblk "${blk_opts}" "${kiwi_oem_installdevice}" |\
+            grep -E "disk|raid" | tr ' ' ":"
+        )
+        device_size=$(echo "${device_meta}" | cut -f2 -d:)
+        list_items="${device} ${device_size}"
+    fi
     if [ -z "${list_items}" ];then
         local no_device_text="No device(s) for installation found"
         report_and_quit "${no_device_text}"