Enable dracut deploy ramdisks

The element builds dracut from source on Ubuntu because the
Ubuntu dracut package is broken and very old, so it can't be
installed properly and causes a number of other issues that
are fixed by using a newer version of Dracut.

This initial version should work in virtualized environments.
Further validation of its suitability for real baremetal
deployments will need to be done in the future, but this should
be sufficient to enable that work.

Regarding Dracut specifically, in order to limit the changes
needed in the existing scripts this element continues to use a
cut down version of the /init script that we were building for the
existing ramdisk.  However, instead of running it as pid 0 it is
run as a Dracut pre-mount hook.  This allows Dracut to set up all
of the hardware and system bits, while falling early enough in the
Dracut sequence to complete the deployment before Dracut would try
to boot off the hard disk.

bp tripleo-juno-dracut-ramdisks
Change-Id: I144c8993fe040169f440bd4f7a428fdbe3d745cf

bin/disk-image-create

@@ -63,6 +63,7 @@ function show_options () {
     echo "    --qemu-img-options -- option flags to be passed directly to qemu-img."
     echo "       Options need to be comma separated, and follow the key=value pattern."
     echo "    --root-label label -- label for the root filesystem.  Defaults to 'cloudimg-rootfs'."
+    echo "    --ramdisk-element -- specify the main element to be used for building ramdisks."
     if [ "$IS_RAMDISK" == "0" ]; then
         echo "    -n skip the default inclusion of the 'base' element"
         echo "    -p package[,package,package] -- list of packages to install in the image"
@@ -87,7 +88,7 @@ function show_options () {
 INSTALL_PACKAGES=""
 COMPRESS_IMAGE="true"
 DIB_ROOT_LABEL=""
-TEMP=`getopt -o a:ho:t:xucnp: -l no-tmpfs,offline,help,min-tmpfs:,image-size:,image-cache:,max-online-resize:,qemu-img-options:,root-label: -n $SCRIPTNAME -- "$@"`
+TEMP=`getopt -o a:ho:t:xucnp: -l no-tmpfs,offline,help,min-tmpfs:,image-size:,image-cache:,max-online-resize:,qemu-img-options:,ramdisk-element:,root-label: -n $SCRIPTNAME -- "$@"`
 if [ $? -ne 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi
 
 # Note the quotes around `$TEMP': they are essential!
@@ -112,6 +113,7 @@ while true ; do
         --offline) shift; export DIB_OFFLINE=1;;
         --qemu-img-options) QEMU_IMG_OPTIONS=$2; shift 2;;
         --root-label) export DIB_ROOT_LABEL=$2; shift 2;;
+        --ramdisk-element) RAMDISK_ELEMENT=$2; shift 2;;
         --) shift ; break ;;
         *) echo "Internal error!" ; exit 1 ;;
     esac

elements/deploy-ironic/init.d/80-deploy-ironic

@@ -35,9 +35,11 @@ if [ "$BOOT_METHOD" = "$VMEDIA_BOOT_TAG" ]; then
 else
   TOKEN_FILE=token-$DEPLOYMENT_ID
 
-  if tftp -r $TOKEN_FILE -g $BOOT_SERVER
-    then TOKEN_HEADER="-H 'X-Auth-Token: $(cat $TOKEN_FILE)'"
-    else TOKEN_HEADER=""
+  # Allow multiple versions of the tftp client
+  if tftp -r $TOKEN_FILE -g $BOOT_SERVER || tftp $BOOT_SERVER -c get $TOKEN_FILE; then
+      TOKEN_HEADER="-H 'X-Auth-Token: $(cat $TOKEN_FILE)'"
+  else
+      TOKEN_HEADER=""
   fi
 fi
 

elements/dracut-ramdisk/README.md

@@ -0,0 +1,5 @@
+Build Dracut-based ramdisks
+
+This is an alternative to the `ramdisk` element that uses
+Dracut to provide the base system functionality instead of
+Busybox.

elements/dracut-ramdisk/element-deps

@@ -0,0 +1,3 @@
+pkg-map
+ramdisk-base
+source-repositories

elements/dracut-ramdisk/environment.d/10-dracut-version.bash

@@ -0,0 +1,2 @@
+# Using 037 because that matches the current Fedora package
+export DRACUT_VERSION=037

elements/dracut-ramdisk/extra-data.d/scripts/module/deploy-cmdline.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+# NOTE(bnemec): Dracut doesn't like it if we enable these
+# dib-lint: disable=setu sete setpipefail
+
+source /init-func
+
+find_target() {
+    local DISK=$(getarg disk)
+    local target_disk=
+    t=0
+    while ! target_disk=$(find_disk "$DISK"); do
+        if [ $t -eq 10 ]; then
+            break
+        fi
+        t=$(($t + 1))
+        sleep 1
+    done
+    echo $target_disk
+}
+root=$(find_target)
+
+if [ -n "$root" ]; then
+    rootok=1
+fi
+
+# Dracut doesn't correctly parse the ip argument passed to us.
+# Override /proc/cmdline to rewrite it in a way dracut can grok.
+sed 's/\(ip=\S\+\)/\1:::off/' /proc/cmdline > /run/cmdline
+# Map the existing "troubleshoot" kernel param to the Dracut equivalent.
+sed -i 's/troubleshoot=/rd.shell=/' /run/cmdline
+mount -n --bind -o ro /run/cmdline /proc/cmdline
+# Force Dracut to re-read the cmdline args
+CMDLINE=

elements/dracut-ramdisk/extra-data.d/scripts/module/module-setup.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Dracut is bash too, and it doesn't play nicely with our usual sets
+# dib-lint: disable=setu sete setpipefail
+
+check() {
+    return 0
+}
+
+depends() {
+    return 0
+}
+
+install() {
+    inst_hook cmdline 80 "$moddir/deploy-cmdline.sh"
+    inst_hook pre-mount 50 "$moddir/init.sh"
+}

elements/dracut-ramdisk/install.d/20-install-dracut-deps

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+set -eux
+set -o pipefail
+
+DRACUT_NETWORK="dracut-network"
+if [ 'ubuntu' = "$DISTRO_NAME" ]; then
+    DRACUT_NETWORK=
+    # Install Dracut from source because the packaged version is
+    # broken and old.  For Dracut builds we throw away the chroot
+    # anyway so it won't matter if we've installed some build deps.
+    install-packages build-essential arping
+    pushd /tmp
+    tar xJvf dracut.tar.xz
+    pushd dracut-$DRACUT_VERSION
+    ./configure
+    make
+    make install
+    popd
+    popd
+fi
+
+PACKAGES=$(pkg-map --element dracut-ramdisk ncat tftp)
+install-packages $DRACUT_NETWORK wget $PACKAGES

elements/dracut-ramdisk/pkg-map

@@ -0,0 +1,15 @@
+{
+  "family":{
+    "debian":{
+      "ncat":"netcat-traditional",
+      "tftp":"tftp-hpa"
+    },
+    "redhat":{
+      "ncat":"nmap-ncat"
+    }
+  },
+  "default":{
+    "ncat":"ncat",
+    "tftp":"tftp"
+  }
+}

elements/dracut-ramdisk/post-install.d/99-build-dracut-ramdisk

@@ -0,0 +1,63 @@
+#!/bin/bash
+
+set -eux
+set -o pipefail
+
+_LIB="/tmp/ramdisk-build"
+
+source "$_LIB/common-defaults"
+source "$_LIB/img-defaults"
+source "$_LIB/ramdisk-defaults"
+
+source "$_LIB/common-functions"
+source "$_LIB/img-functions"
+source "$_LIB/ramdisk-functions"
+
+KERNEL_VERSION="${DIB_KERNEL_VERSION:-$(find_kernel_version)}"
+MODULE_DIR="$MODULE_ROOT/lib/modules/$KERNEL_VERSION"
+FIRMWARE_DIR="$MODULE_ROOT/lib/firmware"
+LIB_UDEV="$LIB_UDEV_ROOT/lib/udev"
+INIT="$_LIB/scripts/init"
+FUNCTIONS_D="$_LIB/scripts/d"
+MODULE="$_LIB/scripts/module"
+# NOTE(bnemec): IMAGE_ELEMENT is normally set in disk-image-create, but we're
+# not using that to build the image here.
+IMAGE_ELEMENT=
+
+mk_build_dir
+mkdir -p "$TMP_BUILD_DIR/mnt"
+export TMP_HOOKS_PATH=/tmp
+export TMP_MOUNT_PATH="$TMP_BUILD_DIR/mnt"
+
+echo "building ramdisk in $TMP_MOUNT_PATH"
+
+populate_init
+SCRIPT_HOME=/tmp/in_target.d/bin TMP_HOOKS_PATH=/tmp/in_target.d run_d ramdisk-install
+MODULE_PATH="/usr/lib/dracut/modules.d"
+cp -r "$MODULE" "$MODULE_PATH/80deploy-ramdisk"
+cp "$TMP_MOUNT_PATH/init" "$MODULE_PATH/80deploy-ramdisk/init.sh"
+
+# Notes on the options passed to Dracut:
+# -N: Do not build a host-specific ramdisk.  We want to be able to run this ramdisk
+#     on as many different machines as possible.
+# --install: A list of the binaries needed by our ramdisk script fragments.
+# --kernel-cmdline: Kernel parameters to pass to the ramdisk.  rd.neednet is required
+#                   to force Dracut to bring up networking even if it isn't passed a
+#                   network target root.  Pre-loading the ahci module is necessary
+#                   on some systems to ensure that SATA disks are recognized.
+# --include: Files from the chroot to include in the ramdisk.
+# --kver: The kernel version to use, as determined above.
+# --add-drivers: Extra kernel modules to include in the ramdisk.
+# -o: Force omission of these dracut modules.  Our scripts are written for bash,
+#     so dash is not desirable, and plymouth was causing some issues on Ubuntu.
+dracut -N \
+    --install 'tail head awk ifconfig cut expr route ping tgtd tgtadm nc wget curl tftp grep' \
+    --kernel-cmdline "rd.shell rd.debug rd.neednet=1 rd.driver.pre=ahci" \
+    --include "$TMP_MOUNT_PATH/init-func" /init-func \
+    --kver "${KERNEL_VERSION}" \
+    --add-drivers "virtio virtio_net virtio_blk" \
+    -o "dash plymouth" \
+    /tmp/ramdisk
+
+cp "/boot/vmlinuz-${KERNEL_VERSION}" /tmp/kernel
+chmod o+r /tmp/kernel

elements/dracut-ramdisk/source-repository-dracut

@@ -0,0 +1 @@
+dracut file /tmp/dracut.tar.xz https://www.kernel.org/pub/linux/utils/boot/dracut/dracut-$DRACUT_VERSION.tar.xz

lib/common-functions

@@ -233,7 +233,7 @@ function arg_to_elements() {
     IMAGE_ELEMENT="base $IMAGE_ELEMENT"
   fi
   if [ "$IS_RAMDISK" == "1" ]; then
-    IMAGE_ELEMENT="ramdisk $IMAGE_ELEMENT"
+    IMAGE_ELEMENT="$RAMDISK_ELEMENT $IMAGE_ELEMENT"
   fi
   echo "Building elements: $IMAGE_ELEMENT"
 

lib/ramdisk-defaults

@@ -18,6 +18,7 @@
 # options for ramdisk-image-create
 export DIB_NO_TMPFS=${DIB_NO_TMPFS:-1}
 export DIB_MIN_TMPFS=${DIB_MIN_TMPFS:-1}
+export RAMDISK_ELEMENT=${RAMDISK_ELEMENT:-ramdisk}
 source $_LIB/common-defaults
 MODULE_ROOT=${DIB_MODULE_ROOT:-""}
 LIB_UDEV_ROOT=${DIB_LIB_UDEV_ROOT:-""}

lib/ramdisk-functions

@@ -25,7 +25,9 @@ function fullpath() {
 }
 
 function cleanup () {
-  unmount_dir "$TMP_BUILD_DIR/mnt"
+  if [ "$RAMDISK_ELEMENT" != "dracut-ramdisk" ]; then
+    unmount_dir "$TMP_BUILD_DIR/mnt"
+  fi
   if [ -f "$TMP_IMAGE_PATH" ]; then
     loopdev=`sudo losetup -j "$TMP_IMAGE_PATH" | cut -d: -f1`
     if [ -n "$loopdev" ]; then