Adding host system based overlay mounts.

Signed-off-by: Daniel Baumann <daniel.baumann@open-infrastructure.net>

8 files changed, 130 insertions, 2 deletions

diff --git a/lib/container/create b/lib/container/create
index 8080ffa..d1ef901 100755
--- a/lib/container/create
+++ b/lib/container/create
@@ -26,7 +26,7 @@ SCRIPTS="/usr/share/container-tools/scripts"
 
 Parameters ()
 {
-	LONG_OPTIONS="name:,cnt.auto:,bind:,capability:,drop-capability:script:,"
+	LONG_OPTIONS="name:,cnt.auto:,cnt.overlay:,bind:,capability:,drop-capability:script:,"
 	OPTIONS="n:,b:,c:,d:,s:,"
 
 	PARAMETERS="$(getopt --longoptions ${LONG_OPTIONS} --name=${COMMAND} --options ${OPTIONS} --shell sh -- ${@})"
@@ -52,6 +52,11 @@ Parameters ()
 				shift 2
 				;;
 
+			--cnt.overlay)
+				CNT_OVERLAY="${2}"
+				shift 2
+				;;
+
 			-b|--bind)
 				BIND="${2}"
 				shift 2
@@ -87,7 +92,7 @@ Parameters ()
 
 Usage ()
 {
-	echo "Usage: container ${COMMAND} -n|--name NAME [--cnt.auto=true|false|FQDN] [-b|--bind DIRECTORY:DIRECTORY[:OPTIONS]] [-c|--capability CAPABILITY[,CAPABILITY]] [-d|--drop-capability DROP_CAPABILITY[,DROP_CAPABILITY]] [-s|--script SCRIPT] [-- SCRIPT_OPTIONS]" >&2
+	echo "Usage: container ${COMMAND} -n|--name NAME [--cnt.auto=true|false|FQDN] [--cnt.overlay=DIRECTORY_LOWER:DIRECTORY_UPPER:DIRECTORY_WORK:DIRECTORY_MERGED] [-b|--bind DIRECTORY:DIRECTORY[:OPTIONS]] [-c|--capability CAPABILITY[,CAPABILITY]] [-d|--drop-capability DROP_CAPABILITY[,DROP_CAPABILITY]] [-s|--script SCRIPT] [-- SCRIPT_OPTIONS]" >&2
 	exit 1
 }
 
@@ -149,11 +154,31 @@ then
 	done
 fi
 
+# Creating overlay mounts
+if [ -n "${CNT_OVERLAY}" ]
+then
+	CNT_OVERLAYS="$(echo ${CNT_OVERLAY} | sed -e 's|;| |g')"
+
+	for CNT_OVERLAY in ${CNT_OVERLAYS}
+	do
+		DIRECTORY_LOWER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $1 }')"
+		DIRECTORY_UPPER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $2 }')"
+		DIRECTORY_WORK="$(echo ${CNT_OVERLAY} | awk -F: '{ print $3 }')"
+		DIRECTORY_MERGED="$(echo ${CNT_OVERLAY} | awk -F: '{ print $4 }')"
+
+		for DIRECTORY in "${DIRECTORY_LOWER}" "${DIRECTORY_UPPER}" "${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+		do
+			mkdir -p "${DIRECTORY}"
+		done
+	done
+fi
+
 # config
 mkdir -p "${CONFIG}"
 
 sed	-e "s|@CNT_AUTO@|${CNT_AUTO}|g" \
 	-e "s|@CNT_NETWORK_BRIDGE@|${CNT_NETWORK_BRIDGE}|g" \
+	-e "s|@CNT_OVERLAY@|${CNT_OVERLAY}|g" \
 	-e "s|@NAME@|${NAME}|g" \
 	-e "s|@BIND@|${BIND}|g" \
 	-e "s|@BOOT@|yes|g" \
diff --git a/lib/container/start b/lib/container/start
index a4dc033..d5bbbf4 100755
--- a/lib/container/start
+++ b/lib/container/start
@@ -139,6 +139,31 @@ esac
 # config
 if [ -e "${CONFIG}/${NAME}.conf" ]
 then
+	CNT_OVERLAY="$(awk -F= '/^cnt.overlay=/ { print $2 }' ${CONFIG}/${NAME}.conf)"
+
+	if [ -n "${CNT_OVERLAY}" ]
+	then
+		CNT_OVERLAYS="$(echo ${CNT_OVERLAY} | sed -e 's|;| |g')"
+
+		for CNT_OVERLAY in ${CNT_OVERLAYS}
+		do
+			DIRECTORY_LOWER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $1 }')"
+			DIRECTORY_UPPER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $2 }')"
+			DIRECTORY_WORK="$(echo ${CNT_OVERLAY} | awk -F: '{ print $3 }')"
+			DIRECTORY_MERGED="$(echo ${CNT_OVERLAY} | awk -F: '{ print $4 }')"
+
+			for DIRECTORY in "${DIRECTORY_LOWER}" "${DIRECTORY_UPPER}" "${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+			do
+				mkdir -p "${DIRECTORY}"
+			done
+
+			if ! findmnt -n -o SOURCE "${DIRECTORY_MERGED}" | grep -qs '^cnt.overlay-'
+			then
+				mount cnt.overlay-${NAME} -t overlay -olowerdir="${DIRECTORY_LOWER}",upperdir="${DIRECTORY_UPPER}",workdir="${DIRECTORY_WORK}",default_permissions "${DIRECTORY_MERGED}"
+			fi
+		done
+	fi
+
 	BIND="$(awk -F= '/^bind=/ { print $2 }' ${CONFIG}/${NAME}.conf)"
 
 	if [ -n "${BIND}" ]
diff --git a/lib/container/stop b/lib/container/stop
index dc78f05..ec24d51 100755
--- a/lib/container/stop
+++ b/lib/container/stop
@@ -94,6 +94,29 @@ STATE="$(machinectl show ${NAME} 2>&1 | awk -F= '/^State=/ { print $2 }')"
 
 case "${CLEAN}" in
 	true)
+		# Removing overlay mounts
+		CNT_OVERLAY="$(awk -F= '/^cnt.overlay=/ { print $2 }' ${CONFIG}/${NAME}.conf)"
+
+		if [ -n "${CNT_OVERLAY}" ]
+		then
+			CNT_OVERLAYS="$(echo ${CNT_OVERLAY} | sed -e 's|;| |g')"
+
+			for CNT_OVERLAY in ${CNT_OVERLAYS}
+			do
+				DIRECTORY_LOWER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $1 }')"
+				DIRECTORY_UPPER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $2 }')"
+				DIRECTORY_WORK="$(echo ${CNT_OVERLAY} | awk -F: '{ print $3 }')"
+				DIRECTORY_MERGED="$(echo ${CNT_OVERLAY} | awk -F: '{ print $4 }')"
+
+				umount -f "${DIRECTORY_MERGED}"
+
+				for DIRECTORY in "${DIRECTORY_LOWER}" "${DIRECTORY_UPPER}" "${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+				do
+					rmdir --ignore-fail-on-non-empty --parents ${DIRECTORY} > /dev/null 2>&1 || true
+				done
+			done
+		fi
+
 		# Removing bind mounts
 		BIND="$(awk -F= '/^bind=/ { print $2 }' ${CONFIG}/${NAME}.conf)"
 
diff --git a/share/config/container.conf.in b/share/config/container.conf.in
index dd52adb..b0211af 100644
--- a/share/config/container.conf.in
+++ b/share/config/container.conf.in
@@ -3,6 +3,7 @@
 [start]
 cnt.auto=@CNT_AUTO@
 cnt.network-bridge=@CNT_NETWORK_BRIDGE@
+cnt.overlay=@CNT_OVERLAY@
 bind=@BIND@
 boot=@BOOT@
 capability=@CAPABILITY@
diff --git a/share/doc/examples/cairon-backports.cfg b/share/doc/examples/cairon-backports.cfg
index eed9fd6..8243bbc 100644
--- a/share/doc/examples/cairon-backports.cfg
+++ b/share/doc/examples/cairon-backports.cfg
@@ -64,4 +64,5 @@ container-tools cnt-debconf/nameserver/options string timeout:1 attempts:1
 #container-tools cnt-debconf/container-command string 
 #container-tools cnt-debconf/host-command string 
 container-tools cnt-debconf/auto string FQDN
+#container-tools cnt-debconf/overlay string 
 #container-tools cnt-debconf/bind string 
diff --git a/share/man/container-create.1.txt b/share/man/container-create.1.txt
index b7a4f01..4fe592f 100644
--- a/share/man/container-create.1.txt
+++ b/share/man/container-create.1.txt
@@ -56,6 +56,9 @@ The following container-create options are available:
 *-b, --bind='DIRECTORY:DIRECTORY[:OPTIONS][;DIRECTORY:DIRECTORY[:OPTIONS]]'*::
 	Specify container bind mounts, see systemd-nspawn(1) --bind option.
 
+*--cnt-overlay='DIRECTORY_LOWER:DIRECTORY_UPPER:DIRECTORY_WORK:DIRECTORY_MERGED[;DIRECTORY_UPPER:DIRECTORY_LOWER:DIRECTORY_WORK:DIRECTORY_MERGED]'*::
+	Specify container overlay mounts, see Documentation/filesystems/overlayfs.txt.
+
 
 SCRIPTS
 -------
diff --git a/share/scripts/debconf b/share/scripts/debconf
index aa1c798..4c89e6f 100755
--- a/share/scripts/debconf
+++ b/share/scripts/debconf
@@ -909,6 +909,7 @@ Commands ()
 
 	sed -i -e "s|^cnt.auto=.*|cnt.auto=${CNT_AUTO}|" "${CONFIG}/${NAME}.conf"
 	sed -i -e "s|^cnt.network-bridge=.*|cnt.network-bridge=${HOST_INTERFACE_NAME}:${NETWORK0_BRIDGE:-br0}|g" "${CONFIG}/${NAME}.conf"
+	sed -i -e "s|^cnt.overlay=.*|cnt.overlay=${CNT_OVERLAY}|g" "${CONFIG}/${NAME}.conf"
 	sed -i -e "s|^bind=.*|bind=${BIND}|" "${CONFIG}/${NAME}.conf"
 	sed -i -e "s|^network-veth-extra=.*|network-veth-extra=${HOST_INTERFACE_NAME}:eth0|g" "${CONFIG}/${NAME}.conf"
 
@@ -1010,12 +1011,54 @@ then
 	done
 fi
 
+# Mounting overlay mounts
+if [ -n "${CNT_OVERLAY}" ]
+then
+	CNT_OVERLAYS="$(echo ${CNT_OVERLAY} | sed -e 's|;| |g')"
+
+	for CNT_OVERLAY in ${CNT_OVERLAYS}
+	do
+		DIRECTORY_LOWER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $1 }')"
+		DIRECTORY_UPPER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $2 }')"
+		DIRECTORY_WORK="$(echo ${CNT_OVERLAY} | awk -F: '{ print $3 }')"
+		DIRECTORY_MERGED="$(echo ${CNT_OVERLAY} | awk -F: '{ print $4 }')"
+
+		for DIRECTORY in "${DIRECTORY_LOWER}" "${DIRECTORY_UPPER}" "${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+		do
+			mkdir -p "${DIRECTORY}"
+		done
+
+		mount -t overlay overlay-${NAME} -olowerdir="${DIRECTORY_LOWER}",upperdir="${DIRECTORY_UPPER}",workdir="${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+	done
+fi
+
 Configure_system "${MACHINES}/${NAME}"
 Configure_network "${MACHINES}/${NAME}"
 Cleanup_system "${MACHINES}/${NAME}"
 
 Commands "${MACHINES}/${NAME}"
 
+# Unmounting overlay mounts
+if [ -n "${CNT_OVERLAY}" ]
+then
+	CNT_OVERLAYS="$(echo ${CNT_OVERLAY} | sed -e 's|;| |g')"
+
+	for CNT_OVERLAY in ${CNT_OVERLAYS}
+	do
+		DIRECTORY_LOWER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $1 }')"
+		DIRECTORY_UPPER="$(echo ${CNT_OVERLAY} | awk -F: '{ print $2 }')"
+		DIRECTORY_WORK="$(echo ${CNT_OVERLAY} | awk -F: '{ print $3 }')"
+		DIRECTORY_MERGED="$(echo ${CNT_OVERLAY} | awk -F: '{ print $4 }')"
+
+		umount -f "${DIRECTORY_MERGED}"
+
+		for DIRECTORY in "${DIRECTORY_LOWER}" "${DIRECTORY_UPPER}" "${DIRECTORY_WORK}" "${DIRECTORY_MERGED}"
+		do
+			rmdir --ignore-fail-on-non-empty --parents ${DIRECTORY} > /dev/null 2>&1 || true
+		done
+	done
+fi
+
 # Unmounting bind mounts
 if [ -n "${BIND}" ]
 then
diff --git a/share/scripts/debconf.d/0003-debconf b/share/scripts/debconf.d/0003-debconf
index 15a6a15..548fb07 100755
--- a/share/scripts/debconf.d/0003-debconf
+++ b/share/scripts/debconf.d/0003-debconf
@@ -1063,6 +1063,13 @@ Internal_options ()
 	fi
 
 	echo "BIND=\"${BIND}\"" >> "${DEBCONF_TMPDIR}/debconf.default"
+
+	if db_get cnt-debconf/overlay
+	then
+		CNT_OVERLAY="${RET}" # string (w/ empty)
+	fi
+
+	echo "CNT_OVERLAY=\"${CNT_OVERLAY}\"" >> "${DEBCONF_TMPDIR}/debconf.default"
 }
 
 Distribution