bin/vm: Support portmapping, custom memory and partial custom image

1 files changed, 68 insertions, 20 deletions

diff --git a/bin/vm b/bin/vm
index 12fd6c8..42b673b 100755
--- a/bin/vm
+++ b/bin/vm
@@ -5,7 +5,7 @@ set -eu
 usage() {
 	cat <<-'EOF'
 		Usage:
-		  vm [-G] [-n] [-S] [-v] ACTION [OS [-- QEMU_OPTIONS...]]
+		  vm [-G] [-i IMAGE ] [-n] [-p PORTMAP ] [-S] [-v] ACTION [OS [-- QEMU_OPTIONS...]]
 		  vm -h
 	EOF
 }
@@ -16,8 +16,12 @@ help() {
 
 		Options:
 		  -G              use graphics
+		  -i IMAGE        provide a custom QCoW2 image file
+		  -m MEMORY       memory (default: 1G)
 		  -n              dry-run: don't execute any code, assumes -v
 		  -S              don't write to VM image (snapshot on)
+		  -p PORTMAP      map the host port $HOSTP to the guest port
+		                  $GUESTP using the $HOSTP:$GUESTP syntax
 		  -v              verbose mode
 		  -h, --help      show this message
 
@@ -51,9 +55,10 @@ help() {
 
 		Examples:
 
-		  Start the VM for Alpine in verbose mode:
+		  Start the VM for Alpine in verbose mode, with guest port 8000
+		  becoming available to the host via port 5555:
 
-		    $ vm -v up alpine
+		    $ vm -v -p 5555:8000 up alpine
 
 
 		  Stop the VM for Slackware, which was already down:
@@ -93,19 +98,31 @@ for flag in "$@"; do
 	esac
 done
 
+IMAGE=''
 DRY_RUN=false
 GRAPHICS=false
+MEMORY=1G
+PORTMAPS=''
 SNAPSHOT=false
 VERBOSE=false
-while getopts 'GnSvh' flag; do
+while getopts 'Gi:m:np:Svh' flag; do
 	case "$flag" in
 		G)
 			GRAPHICS=true
 			;;
+		i)
+			IMAGE="$OPTARG"
+			;;
+		m)
+			MEMORY="$OPTARG"
+			;;
 		n)
 			DRY_RUN=true
 			VERBOSE=true
 			;;
+		p)
+			PORTMAPS="$PORTMAPS $OPTARG"
+			;;
 		S)
 			SNAPSHOT=true
 			;;
@@ -152,12 +169,32 @@ guess_name() {
 	printf '%s\n' "$(basename "$IMAGES" .qcow2)"
 }
 
+guess_arch() {
+	NAME="$(echo "$1" | cut -d- -f2)"
+	case "$NAME" in
+		amd64)
+			printf 'x86_64'
+			;;
+		*)
+			printf '%s' "$NAME"
+			;;
+	esac
+}
+
+hostfwd() {
+	for m in "$@"; do
+		HOST="$( echo "$m" | cut -d: -f1)"
+		GUEST="$(echo "$m" | cut -d: -f2)"
+		printf ',hostfwd=tcp::%s-:%s' "$HOST" "$GUEST"
+	done
+}
+
 write_ssh_config() {
-	for port in "$RUNDIR"/*.port; do
+	for port in "$RUNDIR"/*.ssh; do
 		if [ ! -e "$port" ]; then
 			break
 		fi
-		NAME="$(basename "$port" .port)"
+		NAME="$(basename "$port" .ssh)"
 		PORT="$(cat "$port")"
 		cat <<-EOF
 			Host $NAME
@@ -196,12 +233,14 @@ case "$ACTION" in
 				break
 			fi
 			NAME="$(basename "$img" .qcow2)"
+			PORTS=''
 			if [ -e "$RUNDIR/$NAME.pid" ]; then
 				STATUS=up
+				PORTS="$(sed 's/ /,/g' "$RUNDIR/$NAME.ports")"
 			else
 				STATUS=down
 			fi
-			printf '%s\t%s\n' "$NAME" "$STATUS"
+			printf '%s\t%s\t%s\n' "$NAME" "$STATUS" "$PORTS"
 		done
 		;;
 	up)
@@ -212,8 +251,10 @@ case "$ACTION" in
 		fi
 
 		OS="$(guess_name "$OS")"
+		ARCH="$(guess_arch "$OS")"
 		PID_F="$RUNDIR/$OS.pid"
-		PORT_F="$RUNDIR/$OS.port"
+		SSH_PORT_F="$RUNDIR/$OS.ssh"
+		PORTMAPS_F="$RUNDIR/$OS.ports"
 
 		if [ -e "$PID_F" ]; then
 			printf 'The VM for "%s" is already running with PID %s.\n' \
@@ -221,15 +262,20 @@ case "$ACTION" in
 			exit 1
 		fi
 
-		PORT="$(free-port)"
-		QCOW="$QCOW_DIR"/"$OS".qcow2
+		if [ -z "$IMAGE" ]; then
+			IMAGE="$QCOW_DIR"/"$OS".qcow2
+		fi
+
+		SSH_PORT="$(free-port)"
+		PORTMAPS="$SSH_PORT:22${PORTMAPS}"
+		HOSTFWD="$(hostfwd $PORTMAPS)"
 
 		# shellcheck disable=2086
-		set -- qemu-system-x86_64 \
-			-m 1G                                           \
-			-nic user,model=virtio,hostfwd=tcp::"$PORT"-:22 \
-			-drive file="$QCOW",media=disk,if=virtio        \
-			-enable-kvm                                     \
+		set -- qemu-system-"$ARCH" \
+			-m "$MEMORY"                              \
+			-nic user,model=virtio"$HOSTFWD"          \
+			-drive file="$IMAGE",media=disk,if=virtio \
+			-enable-kvm                               \
 			$FLAGS "$@"
 
 		if [ "$DRY_RUN" = true ]; then
@@ -244,8 +290,9 @@ case "$ACTION" in
 		"$@" 1>>"$LOGS" 2>&1 &
 		PID=$!
 		set +x
-		printf '%s' "$PID"  > "$PID_F"
-		printf '%s' "$PORT" > "$PORT_F"
+		printf '%s' "$PID"      > "$PID_F"
+		printf '%s' "$SSH_PORT" > "$SSH_PORT_F"
+		printf '%s' "$PORTMAPS" > "$PORTMAPS_F"
 
 		write_ssh_config
 		;;
@@ -258,7 +305,8 @@ case "$ACTION" in
 
 		OS="$(guess_name "$OS")"
 		PID_F="$RUNDIR/$OS.pid"
-		PORT_F="$RUNDIR/$OS.port"
+		SSH_PORT_F="$RUNDIR/$OS.ssh"
+		PORTMAPS_F="$RUNDIR/$OS.port"
 
 		if [ ! -e "$PID_F" ]; then
 			printf 'The VM for "%s" is not running, already.\n' "$OS" >&2
@@ -268,10 +316,10 @@ case "$ACTION" in
 		PID="$(cat "$PID_F")"
 
 		if [ "$DRY_RUN" = true ]; then
-			echo rm -f "$PID_F" "$PORT_F"
+			echo rm -f "$PID_F" "$SSH_PORT_F" "$PORTMAPS_F"
 			echo kill "$PID"
 		else
-			rm -f "$PID_F" "$PORT_F"
+			rm -f "$PID_F" "$SSH_PORT_F" "$PORTMAPS_F"
 			kill "$PID"
 		fi