[Qemu-devel] [PATCH 3/3] scripts: A script to create linux container using qemu-linux-user.

[Laurent Vivier <laurent@vivier.eu>]

sudo qemu-create-lxc.sh <target>

This script mixes linux container, binfmt and qemu to create hybrid linux
container : <target> container on an host kernel.

It will create "light" emulated virtual machine with several steps :
- create a linux-user qemu-<target>
- define it as the binfmt interpreter (using qemu-update-binfmt).
- install a base debian system under /containers/<target> using debootstrap.
  and set a minimal configuration.
- define a linux container

Then you can start the container using : sudo lxc-start -n virt<target>

TARGETS STATUS:

alpha: cannot run debootstrap --second stage*, but chroot is usable
m68k: need patches from qemu-m68k, after that, all is working fine.
mips: container can be started, but console login hangs.
ppc: works fine*
sparc: cannot run debootstrap --second stage (cannot fork)
raspberrypi: (=armhf+raspbian) works*

* needs patches I sent to the mailing-list previously

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 scripts/qemu-create-lxc.sh |  280 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 280 insertions(+)
 create mode 100755 scripts/qemu-create-lxc.sh

diff --git a/scripts/qemu-create-lxc.sh b/scripts/qemu-create-lxc.sh
new file mode 100755
index 0000000..4d51e61
--- /dev/null
+++ b/scripts/qemu-create-lxc.sh
@@ -0,0 +1,280 @@
+QEMU_PATH=$(dirname $(dirname $(readlink -f $0)))
+
+TARGET_LIST="i386 m68k alpha sparc mips ppc raspberrypi"
+
+set_i386() {
+	: nothing specific
+}
+
+set_m68k() {
+	DEBIAN_REPO=http://archive.debian.org/debian
+	DEBIAN_DIST=etch-m68k
+	DEBIAN_SIGN=55BE302B
+
+        CONFIGURE_PARAMS=--m68k-default-cpu=m68040
+}
+
+set_alpha() {
+	DEBIAN_REPO=http://archive.debian.org/debian
+	DEBIAN_DIST=lenny
+}
+
+set_sparc() {
+	QEMU_TARGET=sparc32plus
+}
+
+set_mips() {
+	: nothing specific
+}
+
+set_ppc() {
+	DEBIAN_TARGET=powerpc
+}
+
+set_raspberrypi() {
+	DEBIAN_REPO=http://archive.raspbian.org/raspbian
+	DEBIAN_DIST=wheezy
+	DEBIAN_SIGN=""
+	DEBIAN_TARGET=armhf
+	QEMU_TARGET=arm
+}
+
+check_target() {
+	found=0
+	for available in $TARGET_LIST
+	do
+		if [ "$available" = "$TARGET" ]
+		then
+			found=1
+			break;
+		fi
+	done
+	if [ $found -eq 0 ]
+	then
+		echo "ERROR: unknown target $TARGET" 1>&2
+		exit 1
+	fi
+
+	# generic values
+
+	CONTAINER_NAME=virt${TARGET}
+	CONTAINER_PATH=/containers/${TARGET}
+	LXC_CONF=$HOME/lxc-${TARGET}.conf
+
+	DEBIAN_REPO=http://ftp.debian.org/debian
+	DEBIAN_DIST=stable
+	DEBIAN_SIGN=""
+	DEBIAN_TARGET=$TARGET
+
+	QEMU_TARGET=$TARGET
+
+	CHECK_BIN=check_default
+
+	# target specific values
+
+	set_$TARGET
+
+	QEMU_BIN=${QEMU_PATH}/build-${QEMU_TARGET}/${QEMU_TARGET}-linux-user/qemu-${QEMU_TARGET}
+}
+
+check_m68k() {
+	if ${QEMU_BIN} -cpu help | grep -q ">m68040"
+	then
+		echo "Found an existing qemu-m68k, use it !" 1>&2
+		return 0
+	fi
+	echo "Found an existing qemu-m68k, but with no m68040 emulation" 1>&2
+	echo "Please, remove it" 1>&2
+	echo "m68040 emulation is available from " 1>&2
+	echo "git clone git://gitorious.org/qemu-m68k/qemu-m68k.git"
+	exit 1
+}
+
+check_default() {
+	test -e ${QEMU_BIN}
+}
+
+installed_dpkg() {
+	dpkg --status "$1" > /dev/null 2>&1
+}
+
+check_env() {
+	if [ ! -e /etc/debian_version ]
+	then
+		echo "ERROR: this script works only on Debian based distro" 1>&2
+		exit 1
+	fi
+	for pkg in zlib1g gcc make debootstrap lxc
+	do
+		if  ! installed_dpkg $pkg
+		then
+			echo "ERROR: $pkg is needed" 1>&2
+			exit 1
+		fi
+	done
+}
+
+create_qemu() {
+	if [ -e "${QEMU_BIN}" ]
+	then
+		if ${CHECK_BIN}
+		then
+			return 0
+		fi
+	fi
+	echo "cd ${QEMU_PATH} && \
+	mkdir build-${QEMU_TARGET} && \
+	cd build-${QEMU_TARGET} && \
+	../configure --static ${CONFIGURE_PARAMS} \
+		     --target-list=${QEMU_TARGET}-linux-user && \
+	make" | sudo -i -u ${SUDO_USER}
+	if ! ${CHECK_BIN}
+	then
+		echo "ERROR: generated qemu binary is invalid !" 1>&2
+		exit 1
+	fi
+}
+
+create_root() {
+	# sanity check
+
+	if [ $(readlink -f ${CONTAINER_PATH}/) = "/" ]
+	then
+		echo "ERROR: invalid path ${CONTAINER_PATH}" 1>&2
+		exit 1
+	fi
+
+	# check directory
+
+	if [ -e "${CONTAINER_PATH}" ]
+	then
+		echo "${CONTAINER_PATH} already exists" 1>&2
+		echo "Please, remove it" 1>&2
+		exit 1
+	fi
+
+	# Debian bootstrap
+
+	mkdir -p "${CONTAINER_PATH}"
+	debootstrap --foreign \
+		    --arch=${DEBIAN_TARGET} \
+                    ${DEBIAN_DIST} ${CONTAINER_PATH} \
+		    ${DEBIAN_REPO} && \
+
+	# adding qemu binary
+
+	cp ${QEMU_BIN} ${CONTAINER_PATH}/bin && \
+	${QEMU_PATH}/scripts/qemu-update-binfmt ${QEMU_TARGET} /bin
+
+	# debian bootstrap second stage
+
+	chroot ${CONTAINER_PATH} debootstrap/debootstrap --second-stage
+
+	# configuration
+
+	cat >> ${CONTAINER_PATH}/etc/fstab <<!EOF
+# <file system> <mount point>   <type>  <options>       <dump>  <pass>
+proc		/proc		proc	nodev,noexec,nosuid 0	1
+devpts		/dev/pts	devpts	nodev,noexec,nosuid 0	1
+!EOF
+
+	echo "$CONTAINER_NAME" > ${CONTAINER_PATH}/etc/hostname
+	echo "c:2345:respawn:/sbin/getty 38400 console" >> ${CONTAINER_PATH}/etc/inittab
+
+	cat >> ${CONTAINER_PATH}/etc/network/interfaces <<!EOF
+auto eth0
+iface eth0 inet dhcp
+!EOF
+
+	cat >> ${CONTAINER_PATH}/etc/apt/sources.list <<!EOF
+deb ${DEBIAN_REPO} ${DEBIAN_DIST} main contrib non-free
+deb-src ${DEBIAN_REPO} ${DEBIAN_DIST} main contrib non-free
+!EOF
+
+	rm -f ${CONTAINER_PATH}/dev/ptmx
+
+	if [ "$DEBIAN_SIGN" != "" ]
+	then
+		HOME=/root chroot ${CONTAINER_PATH} gpg --keyserver pgpkeys.mit.edu --recv-key ${DEBIAN_SIGN}
+		HOME=/root chroot ${CONTAINER_PATH} gpg -a --export ${DEBIAN_SIGN} | chroot ${CONTAINER_PATH}  apt-key add -
+	fi
+	chroot ${CONTAINER_PATH} apt-get update
+	chroot ${CONTAINER_PATH} dpkg-reconfigure tzdata
+	chroot ${CONTAINER_PATH} apt-get install locales
+	chroot ${CONTAINER_PATH} dpkg-reconfigure locales
+	chroot ${CONTAINER_PATH} passwd
+}
+
+create_lxc() {
+	cat > ${LXC_CONF} <<!EOF
+lxc.utsname = ${CONTAINER_NAME}
+
+lxc.network.type = veth
+lxc.network.flags = up
+lxc.network.link = lxcbr0
+lxc.network.name = eth0
+
+lxc.pts=1023
+lxc.tty=12
+
+lxc.rootfs = ${CONTAINER_PATH}
+
+lxc.cgroup.devices.deny = a
+lxc.cgroup.devices.allow = c 136:* rwm # pts
+lxc.cgroup.devices.allow = c 254:0 rwm # rtc
+lxc.cgroup.devices.allow = c 5:* rwm
+lxc.cgroup.devices.allow = c 4:* rwm # ttyXX
+lxc.cgroup.devices.allow = c 1:* rwm
+lxc.cgroup.devices.allow = b 7:* rwm # loop
+lxc.cgroup.devices.allow = b 1:* rwm # ram
+
+!EOF
+	lxc-create -n ${CONTAINER_NAME} -f ${LXC_CONF}
+}
+
+TARGET="$1"
+
+if [ "$TARGET" = "" ]
+then
+	echo "ERROR: you must provide a target." 1>&2
+	echo "       Available targets are:" 1>&2
+	echo "       $TARGET_LIST"
+	exit 1
+fi
+
+
+check_env
+check_target
+
+echo "DEBIAN_TARGET : ${DEBIAN_TARGET}"
+echo "QEMU_TARGET   : ${QEMU_TARGET}"
+echo "CONTAINER_NAME: ${CONTAINER_NAME}"
+echo "CONTAINER_PATH: ${CONTAINER_PATH}"
+echo "QEMU_PATH     : ${QEMU_PATH}"
+echo "LXC_CONF      : ${LXC_CONF}"
+echo "DEBIAN_REPO   : ${DEBIAN_REPO}"
+echo "DEBIAN_DIST   : ${DEBIAN_DIST}"
+
+if lxc-list | grep -q ${CONTAINER_NAME}
+then
+	echo "${CONTAINER_NAME} already exists !" 1>&2
+	echo "you can remove it with :" 1>&2
+	echo "    sudo lxc-destroy -n ${CONTAINER_NAME}" 1>&2
+	echo "[WARNING: this will remove the directory too]" 1>&2
+	exit 2
+fi
+
+if [ "$USER" != "root" ]
+then
+	echo "You need to be root to run this command" 2>&1
+	exit 3
+fi
+
+create_qemu
+create_root
+create_lxc
+
+chroot ${CONTAINER_PATH} uname -a
+
+echo "you can now start your container using:"
+echo "    sudo lxc-start -n ${CONTAINER_NAME}"
-- 
1.7.10.4