Merge lp:~smoser/cloud-initramfs-tools/updateroot into lp:cloud-initramfs-tools

[Scott Moser]

[lp:~smoser/cloud-initramfs-tools/updateroot]

127. By Scott Moser on 2016-12-09

merge from trunk

128. By Scott Moser on 2017-01-10

some improvements, fewer subshells

no more subshells, use 'setf' to control setting of 'set -f'.
This allows us to restore it to its previous setting.

Also
 * bug fix here for determining if the rootmnt is writable.
 * bug fix with incorrect logic on mounting rw
 * pass arguments (rootmnt) into apply_updateroot

129. By Scott Moser on 2017-01-10

merge with trunk

=== modified file 'Makefile'
--- Makefile	2016-12-09 10:21:49 +0000
+++ Makefile	2017-01-10 22:22:27 +0000
@@ -1,4 +1,4 @@
-MODULES = growroot rescuevol overlayroot dyn-netconf copymods rooturl
+MODULES = growroot rescuevol overlayroot dyn-netconf copymods rooturl updateroot
 INITRAMFS_D = /usr/share/initramfs-tools
 IRD = $(DESTDIR)/$(INITRAMFS_D)
 ULIB_PRE = $(DESTDIR)/usr/lib/cloud-initramfs-

=== added file 'debian/cloud-initramfs-updateroot.install'
--- debian/cloud-initramfs-updateroot.install	1970-01-01 00:00:00 +0000
+++ debian/cloud-initramfs-updateroot.install	2017-01-10 22:22:27 +0000
@@ -0,0 +1,2 @@
+usr/share/initramfs-tools/hooks/updateroot
+usr/share/initramfs-tools/scripts/*/updateroot

=== added file 'debian/cloud-initramfs-updateroot.postinst'
--- debian/cloud-initramfs-updateroot.postinst	1970-01-01 00:00:00 +0000
+++ debian/cloud-initramfs-updateroot.postinst	2017-01-10 22:22:27 +0000
@@ -0,0 +1,13 @@
+#!/bin/sh
+set -e
+
+case "$1" in
+	configure)
+		dpkg-trigger update-initramfs;;
+	*) exit 0;;
+esac
+
+#DEBHELPER#
+exit 0
+
+# vi: ts=4 noexpandtab

=== added file 'debian/cloud-initramfs-updateroot.postrm'
--- debian/cloud-initramfs-updateroot.postrm	1970-01-01 00:00:00 +0000
+++ debian/cloud-initramfs-updateroot.postrm	2017-01-10 22:22:27 +0000
@@ -0,0 +1,14 @@
+#!/bin/sh
+set -e
+
+case "$1" in
+	remove|purge)
+		dpkg-trigger update-initramfs;;
+	*) exit 0;;
+esac
+
+#DEBHELPER#
+exit 0
+
+# vi: ts=4 noexpandtab
+

=== modified file 'debian/control'
--- debian/control	2016-12-09 10:21:49 +0000
+++ debian/control	2017-01-10 22:22:27 +0000
@@ -85,3 +85,12 @@
 Description: use a tarball or squashfs image in a url as the root filesystem
  Allows user to pass in root=http://example.com/your.tar.gz
  Root filesystem will be tmpfs from that url.
+
+Package: cloud-initramfs-updateroot
+Architecture: all
+Depends: initramfs-tools,
+         ${misc:Depends},
+         ${shlibs:Depends}
+Description: extract a tarball over root filesystem before pivot
+ Allows kernel command line updateroot=http://your.tar.gz
+ And then tarball will be pulled and extracted over the root.

=== added directory 'updateroot'
=== added directory 'updateroot/doc'
=== added file 'updateroot/doc/README.txt'
--- updateroot/doc/README.txt	1970-01-01 00:00:00 +0000
+++ updateroot/doc/README.txt	2017-01-10 22:22:27 +0000
@@ -0,0 +1,69 @@
+updateroot is an initramfs module that allows you to update
+the root filesystem before changing to it.
+
+Each updateroot= on the kernel command line will be downloaded
+and extracted over the top of the root filesystem.  Support is
+present for gzip, xz or no compression as long as urls end in
+.tar.gz, .tgz, .tar.xz, .txz or .tar.
+
+Any files in a .updateroot/ directory inside the tarball that
+are executable will be executed inside the target before
+init is started.
+
+To demo this, first install the cloud-initramfs-updateroot and
+cloud-initramfs-rooturl packages.  That will update your initramfs
+to have these modules.
+
+$ sudo dpkg -i cloud-initramfs-updateroot_*.deb clodu-initramfs-rooturl*.deb
+update-initramfs: Generating /boot/initrd.img-4.4.0-23-generic
+$ sudo update-initramfs -u -k $(uname -r)
+
+# make local copies for permissions and shorter cmdline
+$ sudo cat /boot/vmlinu?-$(uname -r) > kernel
+$ cp /boot/initrd.img-$(uname -r) initrd
+
+# create 'seed.tar' with a nocloud seed
+$ cat > user-data <<EOF
+#cloud-config
+password: passw0rd
+chpasswd: { expire: False }
+ssh_pwauth: True
+EOF
+$ echo "instance-id: $(uuidgen || echo i-abcdefg)" > meta-data
+$ cloud-localds --disk-format=tar-seed-local seed.tar user-data meta-data
+
+# download the latest xenial squashfs
+$ iurl="http://cloud-images.ubuntu.com/daily/server/xenial/20160523"
+$ wget "$iurl/xenial-server-cloudimg-amd64.squashfs"
+
+# serve those files on a python simple web server note that
+# 10.0.2.2 works for the host address in a qemu user mode networking
+$ python -m SimpleHTTPServer 9999 &
+$ burl="http://10.0.2.2:9999"
+
+# set cmdline variable
+$ cmdline="root=$burl/xenial-server-cloudimg-amd64.squashfs"
+$ cmdline="$cmdline updateroot=$burl/seed.tar"
+$ cmdline="$cmdline overlayroot=tmpfs"
+$ cmdline="$cmdline console=ttyS0 -v"
+
+# now boot a qemu guest with no disks and 1G memory.
+$ qemu-system-x86_64 -enable-kvm \
+   -device virtio-net-pci,netdev=net00 \
+   -netdev type=user,id=net00 \
+   -m 1G -nographic -kernel kernel -initrd initrd \
+   -append "$cmdline"
+
+The system should boot to a login prompt and let you in as 'ubuntu:passw0rd'
+
+Log in and you'll see something like:
+
+$ df -h /
+Filesystem      Size  Used Avail Use% Mounted on
+overlayroot     497M   59M  438M  12% /
+
+$ egrep "(/media|overlay)" /proc/mounts 
+/dev/loop0 /media/root-ro squashfs ro,relatime 0 0
+tmpfs-root /media/root-rw tmpfs rw,relatime 0 0
+overlayroot / overlayfs rw,relatime,lowerdir=/media/root-ro,upperdir=/media/root-rw//overlay,workdir=/media/root-rw//overlay-workdir 0 0
+

=== added directory 'updateroot/hooks'
=== added file 'updateroot/hooks/updateroot'
--- updateroot/hooks/updateroot	1970-01-01 00:00:00 +0000
+++ updateroot/hooks/updateroot	2017-01-10 22:22:27 +0000
@@ -0,0 +1,26 @@
+#!/bin/sh
+set -e
+
+prereqs() {
+	local o="/scripts/init-bottom/overlayroot"  p=""
+	for p in "$DESTDIR/" ""; do
+		[ -e "$p$o" ] && echo "overlayroot" && return 0
+	done
+}
+
+[ "$1" = "prereqs" ] && { prereqs; exit; }
+
+. /usr/share/initramfs-tools/hook-functions
+
+needs="tar xz" #gzip gunzip"
+for need in $needs; do fp=$(which $need) && copy_exec "$fp" /bin; done
+
+## The busybox versions of gzip and gunzip are sufficient, so use them rather
+## than the full programs via copy_exec.  However, because of odd behavior in
+## initramfs-tools, if we put symlinks in /bin, then
+## initramfs-tools/hooks/busybox will remove them.  So instead, use /sbin
+bbox="gzip gunzip"
+[ -d "$DESTDIR/sbin" ] || mkdir -p "$DESTDIR/sbin"
+for need in $bbox; do ln -sf ../bin/busybox "$DESTDIR/sbin/$need"; done
+
+# vi: ts=4 noexpandtab

=== added directory 'updateroot/scripts'
=== added directory 'updateroot/scripts/init-bottom'
=== added file 'updateroot/scripts/init-bottom/updateroot'
--- updateroot/scripts/init-bottom/updateroot	1970-01-01 00:00:00 +0000
+++ updateroot/scripts/init-bottom/updateroot	2017-01-10 22:22:27 +0000
@@ -0,0 +1,161 @@
+#!/bin/sh
+#  Copyright, 2016 Scott Moser <[e-mail]>
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see
+#    <http://www.gnu.org/licenses/>.
+VERBOSITY="1"
+
+prereqs() {
+	local o="/scripts/init-bottom/overlayroot"  p=""
+	# basically we run after overlayroot but do not depend on it
+	for p in "$DESTDIR/" ""; do
+		[ -e "$p$o" ] && echo "overlayroot" && return 0
+	done
+}
+
+[ "$1" != "prereqs" ] || { prereqs; exit; }
+
+setf() {
+	# setf 0|1
+	#  set pathname expansion (-f) off or on
+	#     off is an alias for 0
+	#     on is an alias for 1
+	#  stores the current setting in the unscoped variable 'setf'
+	#  returns the previous setting:
+	#     0 if pathname expansion was off
+	#     1 if pathname expansion was on
+	# setf restore [setting]
+	#  restore pathname expansion to 'setting'.
+	#  if setting is not provided, defaults to variable 'setf'
+	if [ "$1" = "restore" ]; then
+		local val=${2:-${setf:-"-"}}
+		[ "$val" = "0" ] && val="-" || val="+"
+		set ${val}f
+		return
+	fi
+
+	local f="" n="0" d=/ r="1"
+	setf="+"
+	for f in "$d/"*; do
+		[ $n -gt 1 ] && break
+		n=$(($n+1))
+	done
+	[ $n -eq 1 -a "$f" = "$d/*" ] && setf="-" && r="0"
+	case "$1" in
+		off|0) set -f;;
+		on|1) set +f;;
+	esac
+	return $r
+}
+
+debug() {
+	local v=$1
+	shift
+	[ $v -lt $VERBOSITY ] && return 0
+	echo "::" "$@"
+}
+
+extract_urls() {
+	local target="$1" url="" zopt="" script="" fails="" ret=""
+	shift
+	for url in "$@"; do
+		case "$url" in
+			*.tar.gz|*.tgz) zopt="z";;
+			*.tar.xz|*.txz) zopt="J";;
+			*) zopt="";;
+		esac
+		debug 1 "# updateroot [$zopt] $url"
+		wget "$url" -O - | tar -C "$target" -xp${zopt}f -
+	done
+	if [ ! -d "$target/.updateroot" ]; then
+		return 0
+	fi
+
+	fails=0
+	setf on; set -- "$target/.updateroot/"*; setf restore
+	for script in "$@"; do
+		[ -f "$script" -a -x "$script" ] || continue
+		debug 1 "running ${script#$target} in target root"
+		chroot "$target" "${script#$target}" || {
+			fails=$(($fails+1))
+			ret=$?
+			log_warn "script '${script#$target/}' exited $ret"
+		}
+	done
+	[ $fails -eq 0 ] || exit 1
+}
+
+apply_updateroot() {
+	local rootmnt="$1" cmdline="$2" ret=""
+	local cmdline urls
+	if [ "$cmdline" = "" ]; then
+		if ! read cmdline < /proc/cmdline; then
+			log_warn "no /proc/cmdline?"
+			return 1
+		fi
+	fi
+	setf off; set -- $cmdline; setf restore
+	for tok in "$@"; do
+		case "$tok" in
+			updateroot=http://*) urls="${urls} ${tok#*=}";;
+		esac
+	done
+	urls=${urls# }
+
+	setf off; set -- $urls; setf restore
+	if [ $# -eq 0 ]; then
+		debug 1 "no updateroot urls configured in cmdline"
+		return 0
+	fi
+
+	if ! configure_networking; then
+		log_warn "failed configuring networking [$?]"
+		return 1
+	fi
+
+	# only mount rw if not already rw
+	local need_remount="false" ret=0 created=true
+	local tfile="$rootmnt/.updateroot.touch"
+	[ -e "$tfile" ] || created=false
+	if ! ( : >> "$tfile" ) >/dev/null 2>&1; then
+		mount -o remount,rw "$rootmnt"
+		ret=$?
+		if $created; then
+			rm -f "$tfile"
+		fi
+		if [ $ret -ne 0 ]; then
+			log_warn "failed mount '$rootmnt' as rw [$ret]."
+			return 1;
+		fi
+		need_remount="true"
+	fi
+	
+	extract_urls "$rootmnt" "$@"
+	ret=$?
+
+	if [ "${need_remount}" = "true" ]; then
+		mount -o remount,ro "$rootmnt" || {
+			log_warn "failed remounting root '$rootmnt' as ro [$?]!"
+			return 1
+		}
+	fi
+
+	return $ret
+}
+
+. /scripts/functions
+
+apply_updateroot "$rootmnt"
+
+# vi: ts=4 noexpandtab