diff options
Diffstat (limited to 'debvm-run')
| -rwxr-xr-x | debvm-run | 130 |
1 files changed, 108 insertions, 22 deletions
@@ -2,46 +2,132 @@ # Copyright 2022 Helmut Grohne <helmut@subdivi.de> # SPDX-License-Identifier: MIT +: <<'POD2MAN' +=head1 NAME + +debvm-run - Run a VM image created by debvm-create + +=head1 SYNOPSIS + +B<debvm-run> [B<-g>] [B<-i> I<image>] [B<-s> I<sshport>] [B<--> I<qemu options>] + +=head1 DESCRIPTION + +B<debvm-run> is essentially a thin wrapper around B<qemu> for running a virtual machine image created by B<debvm-create> or something compatible. +The virtual machine image is expected to be a raw ext4 image with file system label B<debvm>. +The architecture of the machine is detected from the contained B</bin/true>. +It must contain a symbolic link pointing to a kernel image at B</vmlinuz> or B</vmlinux> depending on the architecture and a symbolic link pointing to an initrd image at B</initrd.img>. +Both are extracted and passed to B<qemu>. +A net interface configured for user mode is added automatically. + +=head1 OPTIONS + +=over 8 + +=item B<-g>, B<--graphical> + +By default, the option B<-nographic> is passed to B<qemu> and one interacts with the serial console of the machine. +This configuration is skipped in the presence of this option. + +=item B<-i> I<image>, B<--image>=I<image> + +This option specifies the location of the virtual machine image file. +By default B<rootfs.ext4> in the working directory is used. + +=item B<-s> I<sshport>, B<--sshport>=I<sshport> + +If given, B<qemu> is configured to pass connections to I<127.0.0.1:sshport> to port 22 of the virtual machine. + +=item B<--> I<qemu options> + +All options beyond a double dash are passed to B<qemu>. +This can be used to configure additional hardware components. +One possible use of this method is passing B<-snapshot> to avoid modifying the virtual machine image. + +=back + +=head1 LIMITATIONS + +Due to the way kernel and bootloader are being extracted before running B<qemu>, one cannot upgrade a kernel and then just reboot. +Attempting to do so, will still use the old kernel. +Instead, B<qemu> must be terminated and B<debvm-run> should be launched again to pick up the new kernel. +In order to avoid accidental reboots, one may pass B<-no-reboot> to B<qemu>. + +=head1 SEE ALSO + + debvm-create(1) qemu(1) + +=cut +POD2MAN + set -u -IMAGE=rootfs.ext2 +IMAGE=rootfs.ext4 SSHPORT= GRAPHICAL= +nth_arg() { + shift "$1" + printf "%s" "$1" +} + die() { echo "$*" 1>&2 exit 1 } - usage() { die "usage: $0 [-g] [-i image] [-s sshport] [-- qemu options]" } +usage_error() { + echo "error: $*" 1>&2 + usage +} -while test "$#" -gt 0; do - case "$1" in - -g) - GRAPHICAL=1 - shift - ;; - -i) - test "$#" -eq 1 && usage - IMAGE=$2 - shift 2 +opt_graphical() { + GRAPHICAL=1 +} +opt_image() { + IMAGE=$1 +} +opt_sshport() { + SSHPORT=$1 +} + +while getopts :gi:s:-: OPTCHAR; do + case "$OPTCHAR" in + g) opt_graphical ;; + i) opt_image "$OPTARG" ;; + s) opt_sshport "$OPTARG" ;; + -) + case "$OPTARG" in + help) + usage + ;; + graphical|image|sshport) + test "$OPTIND" -gt "$#" && usage_error "missing argument for --$OPTARG" + "opt_$OPTARG" "$(nth_arg "$OPTIND" "$@")" + OPTIND=$((OPTIND+1)) + ;; + image=*|sshport=*) + "opt_${OPTARG%%=*}" "${OPTARG#*=}" + ;; + *) + usage_error "unrecognized option --$OPTARG" + ;; + esac ;; - -s) - test "$#" -eq 1 && usage - SSHPORT=$2 - shift 2 + :) + usage_error "missing argument for -$OPTARG" ;; - --) - shift - break + '?') + usage_erro "unrecognized option -$OPTARG" ;; *) - usage + die "internal error while parsing command options, please report a bug" ;; esac done +shift "$((OPTIND - 1))" test -f "$IMAGE" || die "image '$IMAGE' not found" test -s "$IMAGE" || die "image '$IMAGE' is empty" @@ -140,9 +226,9 @@ else ;; esac fi -if test "$MAX_SMP" -gt 1; then +if test -z "$MAX_SMP" || test "$MAX_SMP" -gt 1; then NPROC=$(nproc) - test "$NPROC" -gt "$MAX_SMP" && NPROC=$MAX_SMP + test -n "$MAX_SMP" && test "$NPROC" -gt "$MAX_SMP" && NPROC=$MAX_SMP set -- -smp "$NPROC" "$@" fi |