Provide options to create a RAID on ROOT disk

README.md

@@ -8,10 +8,13 @@ standalone script or during bootup via a dracut module.
 ## Kernel command line options for coreos-installer running in the initramfs
 
 * coreos.inst=yes - Instruct the installer to run
-* coreos.inst.install_dev - The block device on the system to install to
+* coreos.inst.install_dev - The block device on the system to install to. In case of 
+using an RAID device it should be a comma separated list of block devices names
 * coreos.inst.image_url - The url of the coreos image to install to this device
 * coreos.inst.ignition_url - The url of the coreos ignition config (optional, enter
   coreos.inst.ignition_url=skip to not load an ignition config)
+* coreos.inst.raid_dev - The RAID device name (optional)
+* coreos.inst.raid_level - The RAID level (optional)
 
 ## Using the installer on FCOS or RHCOS
 

coreos-installer

@@ -378,6 +378,17 @@ write_networking_opts() {
     echo "set ignition_network_kcmdline=\"$(cat /tmp/networking_opts)\"" >> /mnt/boot_partition/ignition.firstboot
 }
 
+############################################################
+# Helper to enable autoassembly of special devices on cmdline
+############################################################
+write_cmdline_opts() {
+    log "Appending rd.auto=1 to Kernel cmdline"
+    mkdir -p /mnt/boot_partition
+    mount_boot_partition /mnt/boot_partition
+    trap 'umount /mnt/boot_partition; trap - RETURN' RETURN
+    sed -i '/linux16/s/$/ rd.auto=1/' /mnt/boot_partition/grub2/grub.cfg
+}
+
 ############################################################
 # START HERE
 ############################################################
@@ -431,8 +442,14 @@ get_img_url() {
 # Validate that selected device exists
 ############################################################
 check_selected_device() {
-    if [ ! -b $DEST_DEV ]
-    then
+    if [ -f /tmp/raid_dev ]; then
+        for dev in $RAID_DEV; do
+            if [ ! -b $dev ]; then
+                log "${dev} does not exist."
+                exit 1
+            fi
+        done
+    elif [ ! -b $DEST_DEV ]; then
         log "${DEST_DEV} does not exist."
         exit 1
     fi
@@ -599,8 +616,13 @@ validate_image() {
 #Wipe any remaining disk labels
 #########################################################
 wipe_target_disk_labels() {
-    log "Wiping ${DEST_DEV}"
-    wipefs --all --force "${DEST_DEV}"
+    if [ -f /tmp/raid_dev ]; then
+        log "Wiping ${RAID_DEV}"
+        wipefs --all --force ${RAID_DEV}
+    else
+        log "Wiping ${DEST_DEV}"
+        wipefs --all --force "${DEST_DEV}"
+    fi
 }
 
 log() {
@@ -612,9 +634,13 @@ log() {
 #And Write the image to disk
 #########################################################
 write_image_to_disk() {
-    log "Writing disk image"
 
     set -o pipefail
+    if [ -f /tmp/raid_dev ]; then
+        log "Creating array device ${DEST_DEV}"
+        mdadm --create ${DEST_DEV} --level=$(cat /tmp/raid_level) --raid-devices=2 ${RAID_DEV} --metadata=1.0 --run
+    fi
+    log "Writing disk image"
     zcat /mnt/dl/imagefile.gz |\
     dd bs=1M iflag=fullblock oflag=direct conv=sparse of="${DEST_DEV}" status=none
     RETCODE=$?
@@ -636,24 +662,32 @@ write_image_to_disk() {
 parse_args() {
     USAGE="Usage: $0 [options]
 Options:
-    -d DEVICE   Install to the given device, alternatively specify
-                coreos.inst.install_dev on the kcmdline.
-    -i IGNITION The URL (or path) to the given Ignition config,
-                alternatively specify coreos.inst.ignition_url on the
-                kcmdline.
-    -b BASEURL  The URL to the image, alternatively specify
-                coreos.inst.image_url on the kcmdline.
-    -h          This.
+    -d DEVICE     Install to the given device(s), alternatively specify
+                  coreos.inst.install_dev on the kcmdline.
+                  Multiple devices separated by commas may be specified
+                  in order to create a RAID device
+    -r RAID_DEV   RAID device name, alternatively specify coreos.inst.raid_dev
+                  on the kcmdline
+    -l RAID_LEVEL RAID level, alternatively specify coreos.inst.raid_level
+                  on the kcmdline
+    -i IGNITION   The URL (or path) to the given Ignition config,
+                  alternatively specify coreos.inst.ignition_url on the
+                  kcmdline.
+    -b BASEURL    The URL to the image, alternatively specify
+                  coreos.inst.image_url on the kcmdline.
+    -h            This.
 
 This tool installs CoreOS style disk images on a block device.
 "
 
-    while getopts "d:i:b:h" OPTION
+    while getopts "d:i:b:r:l:h" OPTION
     do
         case $OPTION in
             d) DEVICE="$OPTARG" ;;
             i) IGNITION="$OPTARG" ;;
             b) BASE_URL="${OPTARG%/}" ;;
+            r) RAID_DEV="${OPTARG%/}" ;;
+            l) RAID_LEVEL="${OPTARG%/}" ;;
             h) echo "$USAGE"; exit;;
             *) exit 1;;
         esac
@@ -673,6 +707,14 @@ This tool installs CoreOS style disk images on a block device.
     then
         echo "${BASE_URL}" > /tmp/image_url
     fi
+    if [[ ! -z "${RAID_DEV}" ]]
+    then
+        echo "${RAID_DEV}" > /tmp/raid_dev
+    fi
+    if [[ ! -z "${RAID_LEVEL}" ]]
+    then
+        echo "${RAID_LEVEL}" > /tmp/raid_level
+    fi
 }
 
 # Main function for running the installer
@@ -687,7 +729,12 @@ main() {
 
     # set a global environment variable that can be used
     # by a few of the functions below.
-    DEST_DEV=$(cat /tmp/selected_dev)
+    if [ -f /tmp/raid_dev ]; then
+        RAID_DEV=$(cat /tmp/selected_dev | sed 's/,/\n/' | sed 's/^/\/dev\//' | tr '\n' ' ')
+        DEST_DEV=$(cat /tmp/raid_dev)
+    else
+        DEST_DEV=$(cat /tmp/selected_dev)
+    fi
     DEST_DEV=/dev/$DEST_DEV
 
     #import_gpg_key
@@ -707,6 +754,11 @@ main() {
     # If one was provided, install the ignition config
     write_ignition_file
 
+    # If RAID creation is required
+    if [ -f /tmp/raid_dev ]; then
+        write_cmdline_opts
+    fi
+
     # If networking options were present, persist to firstboot initramfs
     write_networking_opts
 

dracut/30coreos-installer/parse-coreos.sh

@@ -24,6 +24,19 @@ then
     echo $IGNITION_URL >> /tmp/ignition_url
 fi
 
+local RAID_DEV=$(getarg coreos.inst.raid_dev=)
+if [ ! -z "$RAID_DEV" ]
+then
+    echo "preset RAID device to $RAID_DEV" >> /tmp/debug
+    echo $RAID_DEV >> /tmp/raid_dev
+fi
+
+local RAID_LEVEL=$(getarg coreos.inst.raid_level=)
+if [ ! -z "$RAID_LEVEL" ]
+then
+    echo "preset RAID level to ${RAID_LEVEL}" >> /tmp/debug
+    echo $RAID_LEVEL >> /tmp/raid_level
+fi
 
 # Kernel networking args
 # Currently only persisting `ipv6.disable`, but additional options may be added