bin/vm: v2

- support -S flag for toggling snapshot mode;
- support -G flag for toggling GUI mode;
- dynamically discover available images;
- dynamically find available ports to map to 22.

1 files changed, 113 insertions, 56 deletions

diff --git a/bin/vm b/bin/vm
index 813f1e6..52bcce5 100755
--- a/bin/vm
+++ b/bin/vm
@@ -5,7 +5,7 @@ set -eu
 usage() {
 	cat <<-'EOF'
 		Usage:
-		  vm ACTION [OS]
+		  vm [-G] [-S] [-v] ACTION [OS]
 		  vm -h
 	EOF
 }
@@ -15,6 +15,9 @@ help() {
 
 
 		Options:
+		  -G            use graphics
+		  -S            don't write to VM image (snapshot on)
+		  -v            verbose mode
 		  -h, --help    show this message
 
 		  ACTION        one of:
@@ -27,14 +30,14 @@ help() {
 		Manage the state of known virtual machines.
 
 		The VM QCOW2 images are stored under
-		$XDG_STATE_HOME/euandreh/qemu/, as "$OS.qcow2" files.  The PIDs
+		$XDG_STATE_HOME/vm/qemu/, as "$OS.qcow2" files.  The PIDs
 		of the running images are stored in individual files under
-		$XDG_RUNTIME_DIR/vm-pids/, as "$OS.pid" files.
+		$XDG_RUNTIME_DIR/vm/pids/, as "$OS.pid" files.
 
-		It also generates an SSH configuration file to bu `Included`
-		by the main $XDG_CONFIG_HOME/ssh/config file, which contains
-		one alias entry for each VM, so that one can do a combination
-		of `vm up alpine && ssh alpine`.
+		It also generates an SSH configuration file under
+                $XDG_DATA_HOME/vm/ssh.conf to be `Included` by the main
+                ~/.ssh/config file, which contains one alias entry for each VM,
+                so that one can do a combination of `vm up alpine && ssh alpine`.
 
 
 		Examples:
@@ -53,8 +56,8 @@ help() {
 		  List the available VMs, and their current state:
 
 		    $ vm status
-		    alpine:up
-		    slackware:down
+		    alpine up
+		    slackware down
 		    freebsd:up
 	EOF
 }
@@ -75,8 +78,20 @@ for flag in "$@"; do
 	esac
 done
 
-while getopts 'h' flag; do
+GRAPHICS=false
+SNAPSHOT=false
+VERBOSE=false
+while getopts 'GSvh' flag; do
 	case "$flag" in
+		G)
+			GRAPHICS=true
+			;;
+		S)
+			SNAPSHOT=true
+			;;
+		v)
+			VERBOSE=true
+			;;
 		h)
 			usage
 			help
@@ -91,83 +106,125 @@ done
 shift $((OPTIND - 1))
 
 
-ACTION="${1:-}"
-OS="${2:-}"
 
-eval "$(assert-arg "$ACTION" 'ACTION')"
+QCOW_DIR="${XDG_STATE_HOME:-$HOME/.local/state}"/vm/qemu
+RUNDIR="${XDG_RUNTIME_DIR:-${TMPDIR:-/tmp}}/vm"
+LOGS="$RUNDIR"/logs
+mkdir -p "$RUNDIR" "$QCOW_DIR" "$XDG_DATA_HOME"/vm
 
+guess_name() {
+	PREFIX="$1"
+	IMAGES="$(find "$QCOW_DIR" -type f -name "${PREFIX}*")"
+	COUNT="$(echo "$IMAGES" | wc -l)"
+	if [ "$COUNT" != 1 ]; then
+		printf 'Cannot guess name with the given prefix: "%s".\n' "$PREFIX" >&2
+		printf '\nThe possibilities are:\n' >&2
+		printf '%s\n' "$IMAGES" |
+			xargs -I% basename % .qcow2 |
+			sed 's/^/- /' >&2
+		exit 2
+	fi
+	printf '%s\n' "$(basename "$IMAGES" .qcow2)"
+}
 
-VMS='
-alpine:60022
-'
+write_ssh_config() {
+	for port in "$RUNDIR"/*.port; do
+		if [ ! -e "$port" ]; then
+			break
+		fi
+		NAME="$(basename "$port" .port)"
+		PORT="$(cat "$port")"
+		cat <<-EOF
+			Host $NAME
+			  HostName localhost
+			  Port $PORT
+
+		EOF
+	done > "$XDG_DATA_HOME"/vm/ssh.conf
+}
 
-for vm in $VMS; do
-	NAME="$(echo "$vm" | cut -d: -f1)"
-	PORT="$(echo "$vm" | cut -d: -f2)"
-	cat <<-EOF
-		Host $NAME
-		  HostName localhost
-		  Port $PORT
+write_ssh_config
 
-	EOF
-done > "$XDG_DATA_HOME"/euandreh/vm-ssh.conf
 
-PIDS_DIR="${XDG_RUNTIME_DIR:-${TMPDIR:-/tmp}}/vm-pids"
-PID_F="$PIDS_DIR/$OS.pid"
-mkdir -p "$PIDS_DIR"
+ACTION="${1:-}"
+OS="${2:-}"
 
+eval "$(assert-arg "$ACTION" 'ACTION')"
+
+
+FLAGS=''
+if [ "$GRAPHICS" = false ]; then
+	FLAGS="$FLAGS -nographic"
+else
+	FLAGS="$FLAGS -display sdl"
+fi
+if [ "$SNAPSHOT" = true ]; then
+	FLAGS="$FLAGS -snapshot"
+fi
 
-port_for_os() {
-	_OS="$1"
-	_PORT="$(echo "$VMS" | awk -F: -vOS="$_OS" '$1 == OS { print $2 }')"
-	if [ -z "$_PORT" ]; then
-		printf 'Unknown OS: "%s".\n\n' "$_OS" >&2
-		usage >&2
-		exit 2
-	fi
-	printf '%s' "$_PORT"
-}
 
 case "$ACTION" in
 	status)
-		echo "$VMS" | awk -F: '$0=$1' | while read -r vm; do
-			if [ -e "$PIDS_DIR/$vm.pid" ]; then
+		for img in "$QCOW_DIR"/*.qcow2; do
+			if [ ! -e "$img" ]; then
+				break
+			fi
+			NAME="$(basename "$img" .qcow2)"
+			if [ -e "$RUNDIR/$NAME.pid" ]; then
 				STATUS=up
 			else
 				STATUS=down
 			fi
-			printf '%s:%s\n' "$vm" "$STATUS"
+			printf '%s\t%s\n' "$NAME" "$STATUS"
 		done
 		;;
 	up)
 		eval "$(assert-arg "$OS" 'OS')"
-		PORT="$(port_for_os "$OS")"
+		OS="$(guess_name "$OS")"
+		PID_F="$RUNDIR/$OS.pid"
+		PORT_F="$RUNDIR/$OS.port"
 
 		if [ -e "$PID_F" ]; then
 			printf 'The VM for "%s" is already running with PID %s.\n' \
 				"$OS" "$(cat "$PID_F")" >&2
-		else
-			QCOW="$XDG_STATE_HOME"/euandreh/qemu/"$OS".qcow2
-			qemu-system-x86_64 \
-				-m 1G                                           \
-				-nic user,model=virtio,hostfwd=tcp::"$PORT"-:22 \
-				-drive file="$QCOW",media=disk,if=virtio        \
-				-enable-kvm                                     \
-				-nographic 1>/dev/null 2>&1 &
-			printf '%s' $! > "$PID_F"
+			exit 1
+		fi
+
+		PORT="$(free-port)"
+		QCOW="$QCOW_DIR"/"$OS".qcow2
+		if [ "$VERBOSE" = true ]; then
+			set -x
 		fi
+		# shellcheck disable=2086
+		qemu-system-x86_64 \
+			-m 1G                                           \
+			-nic user,model=virtio,hostfwd=tcp::"$PORT"-:22 \
+			-drive file="$QCOW",media=disk,if=virtio        \
+			-enable-kvm                                     \
+			$FLAGS 1>>"$LOGS" 2>&1 &
+		PID=$!
+		set +x
+		printf '%s' "$PID"  > "$PID_F"
+		printf '%s' "$PORT" > "$PORT_F"
+
+		write_ssh_config
 		;;
 	down)
 		eval "$(assert-arg "$OS" 'OS')"
-		PORT="$(port_for_os "$OS")"
+		OS="$(guess_name "$OS")"
+		PID_F="$RUNDIR/$OS.pid"
+		PORT_F="$RUNDIR/$OS.port"
 
 		if [ ! -e "$PID_F" ]; then
 			printf 'The VM for "%s" is not running, already.\n' "$OS" >&2
-		else
-			# shellcheck disable=2064
-			trap "rm -f $PID_F" EXIT
-			kill "$(cat "$PID_F")"
+			exit 1
 		fi
+
+		PID="$(cat "$PID_F")"
+		rm -f "$PID_F" "$PORT_F"
+		kill "$PID"
+
+		write_ssh_config
 		;;
 	*)
 		printf 'Unrecognized action: "%s".\n\n' "$ACTION" >&2