diff options
Diffstat (limited to 'etc/private/install/vm-gen-service')
| -rwxr-xr-x | etc/private/install/vm-gen-service | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/etc/private/install/vm-gen-service b/etc/private/install/vm-gen-service new file mode 100755 index 0000000..c4938c2 --- /dev/null +++ b/etc/private/install/vm-gen-service @@ -0,0 +1,204 @@ +#! /usr/bin/env bash + +# Generate systemd .service file for QEMU/KVM virtual machines. +# +# Normally the machines are run from a dedicated user account with its home +# directory containing all the relevant files (management scripts, images, +# configurations, and sockets). However, this can be overriden with the +# following options +# +# --home <dir> +# The virtual machines "home" directory. If unspecified, the user's home +# directory is assumed. +# +# --bin <dir> +# The virtual machines management scripts directory. If unspecified, +# <home>/bin is assumed. If specified as relative, then assumed relative +# to <home>. +# +# --etc <dir> +# The virtual machines configuration files directory. If unspecified, +# <home>/etc is assumed. If specified as relative, then assumed relative +# to <home>. +# +# --var <dir> +# The virtual machines image files directory. If unspecified, <home>/var is +# assumed. If specified as relative, then assumed relative to <home>. +# +# --run <dir> +# The virtual machines sockets directory. If unspecified, <home>/run is +# assumed. If specified as relative, then assumed relative to <home>. +# +# If <user> is unspecified, the current user is assumed. If <group> is +# unspecified, the user's primary group is assumed. +# +usage="usage: $0 [<options>] [<user>] [<group>]" + +owd="$(pwd)" +trap "{ cd '$owd'; exit 1; }" ERR +set -o errtrace # Trap in functions. + +function info () { echo "$*" 1>&2; } +function error () { info "$*"; exit 1; } + +home= +bin= +etc= +var= +run= + +while [ "$#" -gt 0 ]; do + case "$1" in + --home) + shift + home="$1" + shift + ;; + --bin) + shift + bin="$1" + shift + ;; + --etc) + shift + etc="$1" + shift + ;; + --var) + shift + var="$1" + shift + ;; + --run) + shift + run="$1" + shift + ;; + *) + break + ;; + esac +done + +user="$1" + +if [ -z "$user" ]; then + user="$(id -un)" +fi + +group="$2" + +if [ -z "$group" ]; then + group="$(id -un "$user")" +fi + +if [ -z "$home" ]; then + home="$(eval echo ~$user)" +fi + +function complete_dir () # <default> <home> <dir> +{ + local r + if [ -z "$3" ]; then + r="$2/$1" + elif [ "${3:0:1}" != "/" ]; then + r="$2/$3" + else + r="$3" + fi + echo "$(realpath --no-symlinks --canonicalize-missing "$r")" +} + +bin="$(complete_dir bin "$home" "$bin")" +etc="$(complete_dir etc "$home" "$etc")" +var="$(complete_dir var "$home" "$var")" +run="$(complete_dir run "$home" "$run")" + +name="vm-$user" +file="$name@.service" + +# Thinks that must be \-escaped: +# +# - $ (including in comments) +# - \ (e.g., in line continuations) +# +cat <<EOF >"$file" +# $file -- QEMU/KVM machine service template for systemd +# +# user: $user +# group: $group +# bin: $bin +# etc: $etc +# var: $var +# run: $run +# +# To install: +# +# sudo cp $file /etc/systemd/system/ +# sudo chmod 644 /etc/systemd/system/$file +# +# cp ... $var/<machine>.img +# nano $etc/<machine>.conf # Specify RAM, CPU, TAP, MAC, etc. +# +# sudo systemctl start $name@<machine> +# sudo systemctl status $name@<machine> +# login-machine $run/<machine>-con.sock +# sudo systemctl stop $name@<machine> +# +# sudo systemctl enable $name@<machine> + +[Unit] +Description=QEMU/KVM virtual machine %I + +Wants=network-online.target +#After=network-online.target +After=multi-user.target + +[Service] +User=$user +Group=$user +UMask=0007 +WorkingDirectory=~ + +Environment=CPU=1 +Environment=RAM=2G + +# These MUST be specific in EnvironmentFile! +# +#Environment=TAP= +#Environment=MAC= + +# Note that using variable expansion in EnvironmentFile does not work (at +# least not with systemd 229). +# +EnvironmentFile=$etc/%i.conf + +# Note that the first word of ExecStart cannot contain variable expansions. +# +ExecStart=$bin/vm-start \\ + --cpu \${CPU} \\ + --ram \${RAM} \\ + --tap \${TAP} \\ + --mac \${MAC} \\ + --monitor $run/%i-mon.sock \\ + --console $run/%i-con.sock \\ + $var/%i.img + +ExecStop=$bin/vm-stop $run/%i-mon.sock + +# Make systemd wait for ExecStop completion. +# +KillMode=none +TimeoutStopSec=60 + +[Install] +WantedBy=multi-user.target +EOF + +info "generated $file for" +info " user: $user" +info " group: $group" +info " bin: $bin" +info " etc: $etc" +info " var: $var" +info " run: $run" |