init.sh: sandboxed borg invocations and new param-change-safeguard

This commit is contained in:
Ludwig Behm 2023-04-06 00:28:43 +02:00
parent 42daa9e35e
commit b419d2de87
Signed by: l.behm
GPG key ID: D344835D63B89384

67
init.sh
View file

@ -8,7 +8,7 @@ NAME=""
LOGIN="$(whoami)"
die () {
echo $1 >&2
echo -e $1 | sed -e 's-^-! -' >&2
exit 1
}
generate_passphrase() {
@ -23,7 +23,30 @@ init_config_dir() {
generate_passphrase > "$CONFIGDIR/borg_passphrase"
ssh-keygen -t ed25519 -N "" -q -f "$CONFIGDIR/ssh_key" -C "borg access from $(hostname --long)"
exec ssh-copy-id -i "$CONFIGDIR/ssh_key.pub" -p $PORT "$LOGIN@$HOST"
ssh-copy-id -i "$CONFIGDIR/ssh_key.pub" -p $PORT "$LOGIN@$HOST"
}
set_env_config() {
local file="$1"
local param="$2"
local value="$3"
# test current config
# file does not exist
[ ! -e $file ] && echo "$param=$value" >> $file
# file isn't readable
[ ! -r $file ] && die "Config file isn't readable: $file"
# file exists and value is set => early exit
local curr_line="$(grep "^$param=" $file)"
if [ "x$curr_line" == "x" ]; then
# file ist nicht änderbar
[ ! -w $file ] && die "Config file isn't writable: $file"
# param isn't set => append
echo "$param=$value" >> $file
elif [ "x${curr_line#$param=}" != "x$value" ]; then
# param is set with different value
die "Environment parameter '$param' is already set to '${curr_line#$param=}' in config file: $file\nPlease confirm that you know what you're doing by manually setting the parameter to the desired value '$value'."
fi
return 0
}
test_ssh() {
ssh -q -o "BatchMode=yes" -i "$CONFIGDIR/ssh_key" -p "$PORT" "$LOGIN@$HOST" "mkdir -p $REMOTE_PATH" \
@ -35,12 +58,21 @@ test_repo_exists() {
return $?
}
invoke_borg() {
(
export BORG_RSH="ssh -i $CONFIGDIR/ssh_key"
export BORG_REPO="ssh://$LOGIN@$HOST:${PORT}${REMOTE_PATH}"
export BORG_PASSPHRASE_FD=0
exec /usr/bin/borg $@ < "$CONFIGDIR/borg_passphrase"
)
# do some sandboxinng
systemd-run --pipe --collect --unit=temp-borg-init-sandbox.service \
--working-directory=/tmp \
-p "ConfigurationDirectory=borg/$NAME" \
-p "CacheDirectory=borg/$NAME" \
-p "ConfigurationDirectoryMode=550" \
-p "CacheDirectoryMode=550" \
-p "PrivateTmp=yes" \
-p "ReadOnlyDirectories=/" \
-p "EnvironmentFile=/etc/borg/$NAME/config.env" \
--setenv=BORG_PASSPHRASE_FD=0 \
--setenv=BORG_BASE_DIR=/tmp/ \
--setenv=BORG_CONFIG_DIR=/etc/borg/$NAME \
--setenv=BORG_CACHE_DIR=/var/cache/borg/$NAME \
/usr/bin/borg $@ < /etc/borg/$NAME/borg_passphrase
}
init_repo() {
echo "> init repo"
@ -57,6 +89,12 @@ usage() {
for arg in "$@"; do
case "$arg" in
-h*)
HOST="${arg#-h}"
;;
--host=*)
HOST="${arg#--host=}"
;;
-p*)
PORT="${arg#-p}"
;;
@ -69,12 +107,6 @@ for arg in "$@"; do
--login=*)
LOGIN="${arg#--login=}"
;;
-h*)
HOST="${arg#-h}"
;;
--host=*)
HOST="${arg#--host=}"
;;
-d*)
REMOTE_PATH="${arg#-d}"
;;
@ -85,7 +117,9 @@ for arg in "$@"; do
usage
;;
*)
[ "x$NAME" == "x" ] || usage
NAME="$arg"
;;
esac
done
@ -100,9 +134,12 @@ echo "> checking config"
[ -r "$CONFIGDIR/ssh_key" ] || die "File isn't readable: $CONFIGDIR/ssh_key"
# write config every time, parameter may change with each invocation
echo "BORG_REPO=ssh://$LOGIN@$HOST:${PORT}${REMOTE_PATH}" > "$CONFIGDIR/config.env"
set_env_config "$CONFIGDIR/config.env" BORG_REPO "ssh://$LOGIN@$HOST:${PORT}${REMOTE_PATH}"
set_env_config "$CONFIGDIR/config.env" BORG_RSH "ssh -i $CONFIGDIR/ssh_key"
[ -r "$CONFIGDIR/config.env" ] || die "File isn't readable: $CONFIGDIR/config.env"
echo "> testing ssh and destination path"
test_ssh || die "Can't establish ssh connection! Try: ssh-copy-id -i $CONFIGDIR/ssh_key.pub -p $PORT $LOGIN@$HOST"