Merge pull request #1339 from schabrolles/GRUB_netboot

Added support for "grub PXE style" on non x86 platform
via the new config variable PXE_CONFIG_GRUB_STYLE
together with another new config variable PXE_TFTP_IP
as described in default.conf and in the example config file
conf/examples/RHEL7-PPC64LE-Mulitpath-PXE-GRUB.conf
because some non x86 platform (like ppc64/ppc64le)
do not support native PXE boot so that now GRUB
could be used as a PXE alternative.

usr/share/rear/conf/default.conf

@@ -434,6 +434,10 @@ PXE_CONFIG_URL=
 # put this before the hostname on the PXE server
 PXE_CONFIG_PREFIX=rear-
 
+# TFPT IP server. needed to create grub menu when PXE_CONFIG_GRUB_STYLE=y
+# If not set, we gonna try to get TFTP IP from PXE_TFTP_URL
+PXE_TFTP_IP=
+
 # where should we put the TFTP files ? (legacy way)
 PXE_TFTP_PATH=/var/lib/rear/output
 # where should we put the TFTP files ? (URL style)
@@ -448,6 +452,12 @@ PXE_CREATE_LINKS=MAC
 # Should I remove old symlinks for this host ? [BOOL]
 PXE_REMOVE_OLD_LINKS=
 
+# Should I use PXE based on GRUB2 instead of PXE legacy. [BOOL] (default is no)
+# PXE based on GRUB2 can be used by none x86 platform (like POWER ppc64/ppc64le).
+# More information on the GRUB PXE setup can be found here :
+# https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Installation_Guide/chap-installation-server-setup.html#sect-network-boot-setup-ppc-grub2
+PXE_CONFIG_GRUB_STYLE=
+
 # The way we start up in our PXE mode (keywords known are 'automatic', 'unattended', and empty)
 # 'automatic' is the auto_recover mode which means boot automatic with ReaR and execute a 'rear recover', but
 # when a question has to be answered (e.g. during migration mode) it will wait on an answer...

usr/share/rear/conf/examples/RHEL7-PPC64LE-Mulitpath-PXE-GRUB.conf

@@ -0,0 +1,36 @@
+# Default is to create Relax-and-Recover rescue media as ISO image
+# set OUTPUT to change that
+# set BACKUP to activate an automated (backup and) restore of your data
+# Possible configuration values can be found in /usr/share/rear/conf/default.conf
+#
+# This file (local.conf) is intended for manual configuration. For configuration
+# through packages and other automated means we recommend creating a new
+# file named site.conf next to this file and to leave the local.conf as it is.
+# Our packages will never ship with a site.conf.
+
+AUTOEXCLUDE_MULTIPATH=n
+BOOT_OVER_SAN=y
+
+OUTPUT=PXE
+OUTPUT_PREFIX_PXE=rear/$HOSTNAME
+
+PXE_CONFIG_GRUB_STYLE=y
+# On your TFTP server:
+# In your tftpboot dir execute the following command to create the netboot directory based on GRUB.
+# grub2-mknetdir --net-directory=/var/lib/tftpboot
+# config directory will be /var/lib/tftpboot/boot/grub2/powerpc-ieee1275
+# More information about setting up a PXE based on Grub on POWER : https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Installation_Guide/chap-installation-server-setup.html#sect-network-boot-setup-ppc-grub2
+PXE_TFTP_IP=XX.YY.ZZ.AA
+PXE_CONFIG_URL="nfs://$PXE_TFTP_IP/var/lib/tftpboot/boot/grub2/powerpc-ieee1275"
+PXE_CREATE_LINKS=IP
+PXE_REMOVE_OLD_LINKS=y
+PXE_TFTP_URL="nfs://$PXE_TFTP_IP/var/lib/tftpboot"
+
+USE_STATIC_NETWORKING=y
+
+BACKUP=NETFS
+BACKUP_URL=nfs://XX.YY.ZZ.AA/NFS/rear
+#####################################
+## Optional
+## Reduce the size of initrd, but can be long and use more CPU (could help when booting PPC64 in POWERVM with TFTP)
+#REAR_INITRD_COMPRESSION=lzma

usr/share/rear/lib/bootloader-functions.sh

@@ -612,3 +612,46 @@ function make_pxelinux_config {
     # end of function make_pxelinux_config
 }
 
+function make_pxelinux_config_grub {
+    net_default_server_opt=""
+
+    # Be sure that TFTP Server IP is set with TFTP_SERVER_IP Variable.
+    # else set it based on PXE_TFTP_UR variable.
+    if [[ -z $PXE_TFTP_IP ]] ; then
+        if [[ -z $PXE_TFTP_URL ]] ; then
+            LogPrint "Can't find TFTP IP information. Variable TFTP_SERVER_IP or PXE_TFTP_URL with clear IP address must be set."
+            return
+        else
+            # Get IP address from PXE_TFTP_URL (ex:http://xx.yy.zz.aa:port/foo/bar)
+            PXE_TFTP_IP=$(echo "$PXE_TFTP_URL" | awk -F'[/:]' '{ print $4 }')
+        fi
+    fi
+
+    if [ ! -z $PXE_TFTP_IP ]; then
+        net_default_server_opt="set net_default_server=$PXE_TFTP_IP"
+    else
+        LogPrint "WARNING: No valid TFTP IP found. GRUB menu will be generated without net_default_server"
+    fi
+
+    # we use this function only when $PXE_CONFIG_URL is set and $PXE_CONFIG_GRUB_STYLE=y
+    # TODO First Draft. Need to complete with all other options (see make_pxelinux_config).
+    echo "menuentry 'Relax-and-Recover v$VERSION' {"
+    echo "insmod tftp"
+    echo "$net_default_server_opt"
+    echo "echo 'Network status: '"
+    echo "net_ls_cards"
+    echo "net_ls_addr"
+    echo "net_ls_routes"
+    echo "echo"
+    echo "echo \" Relax-and-Recover Rescue image\""
+    echo "echo \"---------------------------------\""
+    echo "echo \"build from host: $HOSTNAME ($OS_VENDOR $OS_VERSION $ARCH)\""
+    echo "echo \"kernel $KERNEL_VERSION ${IPADDR:+on $IPADDR} $(date -R)\""
+    echo "echo \"${BACKUP:+BACKUP=$BACKUP} ${OUTPUT:+OUTPUT=$OUTPUT} ${BACKUP_URL:+BACKUP_URL=$BACKUP_URL}\""
+    echo "echo"
+    echo "echo 'Loading kernel ...'"
+    echo "linux (tftp)/$PXE_KERNEL root=/dev/ram0 vga=normal rw $KERNEL_CMDLINE"
+    echo "echo 'Loading initial ramdisk ...'"
+    echo "initrd (tftp)/$PXE_INITRD"
+    echo "}"
+}

usr/share/rear/output/PXE/default/800_copy_to_tftp.sh

@@ -65,7 +65,7 @@ fi
 
 
 if [[ ! -z "$PXE_TFTP_URL" ]] ; then
-    LogPrint "Copied kernel+initrd $( du -shc $KERNEL_FILE "$TMP_DIR/$REAR_INITRD_FILENAME" | tail -n 1 | tr -s "\t " " " | cut -d " " -f 1 ) to $PXE_TFTP_URL"
+    LogPrint "Copied kernel+initrd $( du -shc $KERNEL_FILE "$TMP_DIR/$REAR_INITRD_FILENAME" | tail -n 1 | tr -s "\t " " " | cut -d " " -f 1 ) to $PXE_TFTP_URL/$OUTPUT_PREFIX_PXE"
     umount_url $PXE_TFTP_URL $BUILD_DIR/tftpbootfs
     rmdir $BUILD_DIR/tftpbootfs >&2
     if [[ $? -eq 0 ]] ; then
@@ -77,4 +77,3 @@ else
     # Add to result files
     RESULT_FILES=( "${RESULT_FILES[@]}" "$PXE_TFTP_LOCAL_PATH/$PXE_KERNEL" "$PXE_TFTP_LOCAL_PATH/$PXE_INITRD" "$PXE_TFTP_LOCAL_PATH/$PXE_MESSAGE" )
 fi
-

usr/share/rear/output/PXE/default/810_create_pxelinux_cfg.sh

@@ -25,7 +25,11 @@ fi
 # PXE_CONFIG_PREFIX is a "string" (by default rear-) - is the name of PXE boot configuration of $HOSTNAME
 PXE_CONFIG_FILE="${PXE_CONFIG_PREFIX}$HOSTNAME"
 if [[ ! -z "$PXE_CONFIG_URL" ]] ; then
-    make_pxelinux_config >"$PXE_LOCAL_PATH/$PXE_CONFIG_FILE"
+    if is_true "$PXE_CONFIG_GRUB_STYLE" ; then
+        make_pxelinux_config_grub >"$PXE_LOCAL_PATH/$PXE_CONFIG_FILE"
+    else
+        make_pxelinux_config >"$PXE_LOCAL_PATH/$PXE_CONFIG_FILE"
+    fi
     chmod 444 "$PXE_LOCAL_PATH/$PXE_CONFIG_FILE"
 else
     # legacy way using PXE_LOCAL_PATH default
@@ -53,15 +57,33 @@ if test "$PXE_CREATE_LINKS" -a "$PXE_REMOVE_OLD_LINKS" ; then
 		done
 fi
 
+# When using Grub network boot via tftp/bootp,
+# the client is looking at a file named "grub.cfg-01-<MAC>"
+# or grub.cfg-<IP in hex>. It is like PXE, but prefixed with "grub.cfg-"
+if is_true $PXE_CONFIG_GRUB_STYLE ; then
+    pxe_link_prefix="grub.cfg-"
+else
+    pxe_link_prefix=""
+fi
+
 case "$PXE_CREATE_LINKS" in
 	IP)
 		# look only at IPv4 and skip localhost (127...)
 		ip a | grep inet\ | grep -v inet\ 127 | \
 			while read inet IP junk ; do
 				IP=${IP%/*}
-				ln -sf $v "$PXE_CONFIG_FILE" $(gethostip -x $IP) >&2
-				# to capture the whole subnet as well
-				ln -sf $v "$PXE_CONFIG_FILE" $(gethostip -x $IP | cut -c 1-6) >&2
+                # check if gethostip is available.
+                if has_binary gethostip &>/dev/null ; then
+    				ln -sf $v "$PXE_CONFIG_FILE" $(gethostip -x $IP) >&2
+    				# to capture the whole subnet as well
+    				ln -sf $v "$PXE_CONFIG_FILE" $(gethostip -x $IP | cut -c 1-6) >&2
+                else
+                # if gethostip is not available on your platform (like ppc64),
+                # use awk to generate IP in hex mode.
+                    ln -sf $v "$PXE_CONFIG_FILE" $pxe_link_prefix$(printf '%02X' ${IP//./ }) >&2
+                    # to capture the whole subnet as well
+    				ln -sf $v "$PXE_CONFIG_FILE" $pxe_link_prefix$(printf '%02X' ${IP//./ } | cut -c 1-6) >&2
+                fi
 			done
 		;;
 	MAC)
@@ -93,4 +115,3 @@ else
     # Add to result files
     RESULT_FILES=( "${RESULT_FILES[@]}" "$PXE_LOCAL_PATH/$PXE_CONFIG_FILE" )
 fi
-