Add editvm.sh TEMPLATE CMD command

README.md

@@ -67,6 +67,18 @@ The `mkvm.sh` script takes the type of container to run as first argument. That
 
 Unless the `--keep` argument is passed, the container is also destroyed after running.
 
+## Edit the template filesystem
+
+If you need to change a template's rootfs, for running updates or adding packages, you can use the `editvm.sh` script:
+
+```
+editvm.sh archlinux bash
+```
+
+This will fail if the ramdisk service is still running, so first stop all your containers, stop the ramdisk service, and try again. Don't forget to restart the ramdisk service after you're done.
+
+If the LXC you want to use does not use a rootfs with its own name in the `/ramdisk/persist/` folder, the script will also error out.
+
 ## License
 
 GNU aGPL v3

bin/editvm.sh

@@ -0,0 +1,120 @@
+#! /usr/bin/env bash
+
+help() {
+	echo "editvm.sh DISTRO [CMD] [ARGS]"
+	echo "  Stops the ramdisk and start editing a VM template"
+	echo "  --copy PATHSRC PATHDEST: copy PATHSRC into the container as PATHDEST"
+}
+
+KEEP=0
+
+SYSDIR="/ramdisk/sys"
+TMPDIR="/ramdisk/tmp"
+
+if [ $# -lt 2 ]; then
+	help
+	exit 0
+fi
+
+# Files to copy into container
+COPY=()
+COPYDEST=()
+
+while true; do
+	case "$1" in
+		"-h"|"--help")
+			help
+			exit 0
+			;;
+		"--copy")
+			shift
+			PATHSRC="$1"
+			if [ ! -e "$PATHSRC" ]; then
+				echo "COPY ERROR: File/Folder "$PATHSRC" does not exist."
+				exit 1
+			fi
+			shift
+			PATHDEST="$1"
+			COPY+=("$PATHSRC")
+			COPYDEST+=("$PATHDEST")
+			shift
+			;;
+		*)
+			# Optional args processing finished
+			# If no first argument is passed, syntax error
+			if [[ "$1" = "" ]]; then
+				help
+				exit 1
+			fi
+			TYPE="$1"
+			shift
+			break
+			;;
+	esac
+done
+
+if systemctl is-active ramdisk; then
+	echo "ERROR: Please stop ramdisk.service first"
+	exit 1
+fi
+
+TEMPLATE=/var/lib/lxc/"$TYPE".template
+
+if [ ! -f "$TEMPLATE" ]; then
+	echo "ERROR: No such VM type "$TYPE""
+	exit 1
+fi
+
+export VMNAME="$TYPE-TEMPLATE"
+echo "$VMNAME"
+
+export LXCROOTFS=/ramdisk/persist/$TYPE
+# Check if the rootfs exists... maybe the template actually calls another rootfs
+if [ ! -d "$LXCROOTFS" ]; then
+	echo "ERROR: The container template "$TYPE" does not have its own rootfs. Maybe it's using another rootfs?"
+	echo "Check the lxc.rootfs.path line in "$TEMPLATE" file to be sure."
+	exit 1
+fi
+
+LXCDIR=/var/lib/lxc/"$VMNAME"
+mkdir "$LXCDIR"
+envsubst < "$TEMPLATE" > "$LXCDIR"/config
+
+ROOTFS="$LXCROOTFS"
+echo "template" > "$ROOTFS"/etc/hostname
+
+# Copy files into the VM
+for fileIndex in ${!COPY[@]}; do
+	PATHSRC="${COPY[$fileIndex]}"
+	PATHDEST="$ROOTFS""${COPYDEST[$fileIndex]}"
+	# Create parent dirs
+	PARENTPATHDEST="$(dirname "$PATHDEST")"
+	mkdir -p "$PARENTPATHDEST"
+	cp --dereference -r "$PATHSRC" "$PATHDEST"
+done
+
+CMD="$1"
+shift
+
+if [[ "$CMD" != "" ]]; then
+	#lxc-execute -n "$VMNAME" -- "$CMD" "$@"
+	lxc-start -n "$VMNAME"
+	lxc-attach -n "$VMNAME" -- "$CMD" "$@"
+	if [ $KEEP -eq 0 ]; then
+		lxc-stop --kill "$VMNAME"
+		# Don't destroy VM because we want to keep the rootfs
+		# (we are just editing it live)
+		# lxc-destroy -n "$VMNAME"
+		rm -R /var/lib/lxc/"$VMNAME"
+	fi
+else
+	lxc-start -n "$VMNAME"
+	lxc-attach -n "$VMNAME" bash
+	if [ $KEEP -eq 0 ]; then
+		lxc-stop --kill "$VMNAME"
+		# Don't destroy VM because we want to keep the rootfs
+		# (we are just editing it live)
+		#lxc-destroy -n "$VMNAME"
+		rm -R /var/lib/lxc/"$VMNAME"
+	fi
+fi

bin/mkvm.sh

@@ -67,6 +67,8 @@ fi
 export VMNAME="$TYPE-$RANDOM"
 echo "$VMNAME"
 
+export LXCROOTFS="overlayfs:/ramdisk/sys/$TYPE:/ramdisk/tmp/$VMNAME"
+echo "$LXCROOTFS"
 LXCDIR=/var/lib/lxc/"$VMNAME"
 mkdir "$LXCDIR"
 envsubst < "$TEMPLATE" > "$LXCDIR"/config

setup.sh

@@ -9,6 +9,7 @@ mkdir -p /ramdisk/persist
 
 ln -sf "$(pwd)"/bin/ramdisk.sh /usr/sbin/
 ln -sf "$(pwd)"/bin/mkvm.sh /usr/sbin/
+ln -sf "$(pwd)"/bin/editvm.sh /usr/sbin/
 
 ln -sf "$(pwd)"/ramdisk.service /etc/systemd/system/
 systemctl daemon-reload

templates/archlinux.template

@@ -12,7 +12,8 @@ lxc.net.0.link = lxcbr0
 lxc.net.0.flags = up
 lxc.apparmor.profile = generated
 lxc.apparmor.allow_nesting = 1
-lxc.rootfs.path = overlayfs:/ramdisk/sys/archlinux:/ramdisk/tmp/$VMNAME
+# Use $LXCROOTFS variable which is different between mkvm.sh/editvm.sh
+lxc.rootfs.path = $LXCROOTFS
 
 # Common configuration
 lxc.include = /usr/share/lxc/config/archlinux.common.conf

templates/bullseye.template

@@ -12,7 +12,8 @@ lxc.net.0.link = lxcbr0
 lxc.net.0.flags = up
 lxc.apparmor.profile = generated
 lxc.apparmor.allow_nesting = 1
-lxc.rootfs.path = overlayfs:/ramdisk/sys/bullseye:/ramdisk/tmp/$VMNAME
+# Use $LXCROOTFS variable which is different between mkvm.sh/editvm.sh
+lxc.rootfs.path = $LXCROOTFS
 
 # Common configuration
 lxc.include = /usr/share/lxc/config/debian.common.conf