From 70a8b3f4b57deed5913dd2667f892f0facd34b3d Mon Sep 17 00:00:00 2001
From: "Dustin C. Hatch" <dustin@hatch.name>
Date: Sun, 22 Mar 2015 21:55:47 -0500
Subject: [PATCH] mkvm: Add script to create stand-alone Gentoo VMs

---
 mkvm.sh | 267 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 267 insertions(+)
 create mode 100755 mkvm.sh

diff --git a/mkvm.sh b/mkvm.sh
new file mode 100755
index 0000000..738032b
--- /dev/null
+++ b/mkvm.sh
@@ -0,0 +1,267 @@
+#!/bin/sh
+
+
+usage() {
+	echo "usage: ${0##*/} [options] name [stage_tarball [custom_script]]"
+}
+
+
+usage_full() {
+	usage
+	printf '
+Create a libvirt virtual machine running Gentoo Linux
+
+positional arguments:
+  name                  The libvirt domain name for the VM
+  stage_tarball         Path to the Gentoo stage tarball to extract to the
+                        virtual machine filesystem
+  custom_script         Path to a script to run in the virtual machine chroot
+                        before powering it on
+
+optional arguments:
+  -h, --help            show this help message and exit
+  --hostname, -H        The hostname of the VM  (defaults to the libvirt
+                        domain name, in all lower case)
+  --kernel-pkg, -K      Path to a tarball containing a kernel and modules
+  --pool, -p            The libvirt storage pool in which to create the
+                        virtual disk
+  --disk-size           The size of virtual disk to create (default 6 GB)
+  --disk-format         The image format of the virtual disk (default qcow2)
+  --vram, -r            The amount of RAM to allocate to the VM
+  --vcpus, -c           The number of virtual CPUs to allocate to the VM
+  --vnet, -n            The network adapter on the host to connect to the VM
+  --timezone, -Z        The timezone to set in the VM
+'
+}
+
+invalid_arg() {
+	usage >&2
+	echo "${0##*/}: Unrecognized argument: $1" >&2
+	exit 2;
+}
+
+
+while [ $# -gt 0 ]; do
+	case $1 in
+	--hostname|-H)
+		shift
+		VHOSTNAME=$1
+		shift
+		;;
+	--kernel-pkg|-K)
+		shift
+		KERNEL_PKG=$1
+		shift
+		;;
+	--pool|-p)
+		shift
+		POOL=$1
+		shift
+		;;
+	--disk-size|-s)
+		shift
+		VDISKSIZE=$1
+		shift
+		;;
+	--disk-format|-f)
+		shift
+		VDISKFORMAT=$1
+		shift
+		;;
+	--vram|-r)
+		shift
+		VRAM=$1
+		shift
+		;;
+	--vcpus|-c)
+		shift
+		VCPUS=$1
+		shift
+		;;
+	--vnet|-n)
+		shift
+		VNET=$1
+		shift
+		;;
+	--timezone|-Z)
+		shift
+		TIMEZONE=$1
+		shift
+		;;
+	--help|-h)
+		usage_full
+		exit 0
+		;;
+	-*)
+		invalid_arg $1
+		;;
+	*)
+		if [ -z "${DOMNAME}" ]; then
+			DOMNAME=$1
+			shift
+		elif [ -z "${STAGE_TBZ}" ]; then
+			STAGE_TBZ=$1
+			shift
+		elif [ -z "${CUSTOMIZE}" ]; then
+			CUSTOMIZE=$1
+			shift
+		else
+			invalid_arg $1
+		fi
+		;;
+	esac
+done
+
+
+set -e
+
+
+if [ -z "${DOMNAME}" ]; then
+	usage >&2
+	exit 2
+fi
+
+: ${VHOSTNAME:=$(printf "${DOMNAME}" | tr '[A-Z]' '[a-z]')}
+: ${POOL:=default}
+: ${TIMEZONE:=America/Chicago}
+
+unset $(env | awk -F= '/^LC_/{print $1}')
+export LC_ALL=C
+
+mountpoint=${TMPDIR:-/tmp}/${VHOSTNAME}
+mkdir ${mountpoint}
+
+
+virsh vol-create-as ${POOL} ${DOMNAME}.img \
+	--capacity ${VDISKSIZE:-6G} \
+	--format ${VDISKFORMAT:-qcow2}
+vol_path=$(virsh vol-path ${DOMNAME}.img ${POOL})
+
+echo 'Creating logical volumes and filesystems ...'
+i=$(pgrep -fa ^nbd | sort -k2r | sed -rn '1s/[0-9]+\s+nbd//p')
+blkdev=/dev/nbd$((${i:--1} + 1))
+unset i
+
+sudo /bin/sh -e <<EOS
+qemu-nbd -c ${blkdev} ${vol_path}
+
+sgdisk -a 4096 -Z -g \
+	-n 1::+1M \
+	-t 1:EF02 \
+	-c 1:'BIOS boot partition' \
+	-n 2::+32M \
+	-c 2:'Linux filesystem' \
+	-n 3:: \
+	-t 3:8E00 \
+	-c 3:'Linux LVM' \
+	${blkdev}
+
+pvscan > /dev/null
+
+pvcreate ${blkdev}p3
+vgcreate ${VHOSTNAME} ${blkdev}p3
+lvcreate -nswap -L1G ${VHOSTNAME}
+lvcreate -nroot -L300M ${VHOSTNAME}
+lvcreate -nusr -L1200M ${VHOSTNAME}
+lvcreate -nvar -L600M ${VHOSTNAME}
+lvcreate -nopt -L100M ${VHOSTNAME}
+lvcreate -nhome -L100M ${VHOSTNAME}
+mkswap -Lswap /dev/${VHOSTNAME}/swap
+mkfs.ext4 -q -Lboot ${blkdev}p2
+for v in root usr var opt home; do
+	mkfs.xfs -q -L\$v /dev/${VHOSTNAME}/\$v
+done
+EOS
+
+[ -z "${STAGE_TBZ}" ] && exit 0
+
+echo 'Mounting filesystems ...'
+sudo /bin/sh -e <<EOS
+mount /dev/${VHOSTNAME}/root ${mountpoint}
+
+install -d ${mountpoint}/boot
+mount ${blkdev}p2 ${mountpoint}/boot
+
+for v in usr var opt home; do
+	install -d ${mountpoint}/\$v
+	mount /dev/${VHOSTNAME}/\$v ${mountpoint}/\$v
+done
+EOS
+
+echo 'Extracting stage tarball ...'
+sudo tar -xaf "${STAGE_TBZ}" -C ${mountpoint}
+
+echo 'Configuring system ...'
+sudo /bin/sh -e <<EOS
+mount -t proc proc ${mountpoint}/proc
+mount -t sysfs sysfs ${mountpoint}/sys
+mount -obind /dev ${mountpoint}/dev
+chroot ${mountpoint} grub2-install ${blkdev}
+cat > ${mountpoint}/boot/grub/grub.cfg <<EOF
+timeout=1
+
+menuentry 'Gentoo Linux' {
+	root=hd0,gpt2
+	linux /vmlinuz root=/dev/${VHOSTNAME}/root dolvm net.ifnames=0 quiet
+	initrd /initramfs
+}
+EOF
+
+sed -i s/localhost/${VHOSTNAME}/ ${mountpoint}/etc/conf.d/hostname
+
+cat > ${mountpoint}/etc/fstab <<EOF
+LABEL=swap	none	swap	sw	0 0
+LABEL=boot	/boot	ext4	noauto,noatime	1 2
+/dev/${VHOSTNAME}/root	/	xfs	ro,noatime	0 1
+/dev/${VHOSTNAME}/usr	/usr	xfs	ro,noatime	0 2
+/dev/${VHOSTNAME}/var	/var	xfs	noatime	0 2
+/dev/${VHOSTNAME}/opt	/opt	xfs	ro,noatime	0 2
+/dev/${VHOSTNAME}/home	/home	xfs	noatime	0 2
+tmpfs	/tmp	tmpfs	defaults	0 0
+EOF
+
+rm -rf ${mountpoint}/run/openrc
+ln -snf /proc/self/mounts ${mountpoint}/etc/mtab
+ln -snf /run/resolv.conf ${mountpoint}/etc/resolv.conf
+ln -snf /run/ntp.conf ${mountpoint}/etc/ntp.conf
+
+ln -snf /usr/share/zoneinfo/${TIMEZONE} ${mountpoint}/etc/localtime
+echo ${TIMEZONE} > ${mountpoint}/etc/timezone
+
+passwd -R ${mountpoint} -d root
+EOS
+
+
+if [ -n "${KERNEL_PKG}" ]; then
+	echo 'Extracting kernel package ...'
+	sudo tar --no-same-owner --no-same-permissions --strip-components=1 \
+		--dereference -xaf "${KERNEL_PKG}" -C ${mountpoint}
+fi
+
+
+if [ -f "${CUSTOMIZE}" ]; then
+	echo 'Customizing ...'
+	sudo /bin/sh "${CUSTOMIZE}"
+fi
+
+
+echo 'Cleaning up ...'
+awk '$5~/'${VHOSTNAME}'/{print $5}' /proc/self/mountinfo | tac \
+	| xargs sudo umount
+sudo vgchange -an ${VHOSTNAME}
+sudo qemu-nbd -d ${blkdev}
+
+virt-install --name ${DOMNAME} \
+	--ram ${VRAM:-1024} \
+	--vcpus ${VCPUS:-2} \
+	--os-type linux \
+	--os-variant rhel7 \
+	--boot hd \
+	--disk ${vol_path} \
+	--network bridge=${VNET:-br0} \
+	--graphics vnc \
+	--video cirrus \
+	--memballoon model=virtio \
+	--noautoconsole
+
+rmdir ${mountpoint}