acme.sh: add abort service command and improve interactive messages

For runs started interactively, improve messaging and allow a run to be
aborted with `service acme abort`.

Signed-off-by: Aditya Bhargava <rightaditya@gmail.com>

net/acme-acmesh/files/hook.sh

@@ -39,6 +39,53 @@ link_certs() {
 	fi
 }
 
+handle_signal() {
+	local notify_op=$1
+	local label_op=$2
+	wait_notify() {
+		# wait for acme.sh child job to die, *then* notify about status
+		wait
+		log warn "$label_op aborted: $main_domain"
+		$NOTIFY "${notify_op}-failed"
+		exit 1
+	}
+
+	trap wait_notify TERM
+	# try to kill the cgroup
+	local cgroup=$(cut -d : -f 3 /proc/$$/cgroup)
+	if [[ "$cgroup" == '/services/acme/*' ]]; then
+		# send SIGTERM to all processes in this process's cgroup. this
+		# relies on procd's having set up the cgroup for the instance.
+		read -r -d '' pids < /sys/fs/cgroup${cgroup}/cgroup.procs 
+		kill -TERM $pids 2> /dev/null
+	fi
+
+	# if we're here, either the cgroup wasn't as exected to be set up by
+	# procd or killing the cgroup PIDs failed. try to kill the process
+	# group, assuming this process is the group leader. this is actually
+	# unlikely since procd doesn't set service PGIDs (so they aren't group
+	# leaders).
+	kill -TERM -$$ 2> /dev/null
+
+	# if we're here, cgroup-based killing was avoided or didn't work and
+	# PGID-based killing didn't work. fall back to the raciest option.
+	trap "" TERM
+	term_descendants() {
+		local pids=$@
+		local pid=
+		# `pgrep -P` returns nothing if given a non-existent PID
+		# (even if the PID has live children), so children must
+		# be killed first
+		for pid in $pids; do
+			term_descendants $(pgrep -P "$pid")
+			kill -TERM "$pid" 2> /dev/null
+		done
+	}
+	term_descendants $(jobs -p)
+
+	wait_notify
+}
+
 case $1 in
 get)
 	set --
@@ -67,10 +114,11 @@ get)
 		else
 			set -- "$@" --renew --home "$state_dir" -d "$main_domain"
 			log info "$ACME $*"
-			trap 'log err "Renew failed: SIGINT";$NOTIFY renew-failed;exit 1' INT
-			$ACME "$@"
+			trap "handle_signal renew Renewal" INT TERM
+			$ACME "$@" &
+			wait $!
 			status=$?
-			trap - INT
+			trap - INT TERM
 
 			case $status in
 			0)
@@ -141,12 +189,13 @@ get)
 	set -- "$@" --issue --home "$state_dir"
 
 	log info "$ACME $*"
-	trap 'log err "Issue failed: SIGINT";$NOTIFY issue-failed;exit 1' INT
+	trap "handle_signal issue Issuance" INT TERM
 	"$ACME" "$@" \
 		--pre-hook "$NOTIFY prepare" \
-		--renew-hook "$NOTIFY renewed"
+		--renew-hook "$NOTIFY renewed" &
+	wait $!
 	status=$?
-	trap - INT
+	trap - INT TERM
 
 	case $status in
 	0)

net/acme-common/files/acme.init

@@ -13,7 +13,8 @@ LOG_TAG=acme
 # shellcheck source=net/acme/files/functions.sh
 . "$IPKG_INSTROOT/usr/lib/acme/functions.sh"
 
-extra_command "renew" "Start a certificate renew"
+extra_command "abort" "Abort running certificate issuances/renewals"
+extra_command "renew" "Run certificate issuances/renewals"
 
 delete_nft_rule() {
 	if [ "$NFT_HANDLE" ]; then
@@ -136,6 +137,7 @@ get_cert() {
 	load_options "$section"
 
 	load_credentials() {
+		# use `eval` to correctly strip quotes around credential values
 		eval procd_append_param env "$1"
 	}
 	config_list_foreach "$section" credentials load_credentials
@@ -175,15 +177,20 @@ start_service() {
 }
 
 service_started() {
-	echo "Certificate renewal enabled via cron. To renew now, run '/etc/init.d/acme renew'."
+	echo 'Nightly certificate renewal enabled. To renew now, run `service acme renew`.'
 }
 
 stop_service() {
 	sed -i '\|/etc/init.d/acme|d' /etc/crontabs/root
+	running && stop_aborted="Running certificate renewal(s) aborted and a"
 }
 
 service_stopped() {
-	echo "Certificate renewal is disabled."
+	if enabled; then
+		untilboot=' until next boot. To disable permanently, run `service acme disable`'
+	fi
+	echo "${stop_aborted:-A}utomatic nightly renewal disabled$untilboot."
+	echo 'To re-enable nightly renewal, run `service acme start`. To issue/renew now, run `service acme renew`.'
 }
 
 service_triggers() {
@@ -201,5 +208,21 @@ load_and_run() {
 }
 
 renew() {
+	echo "Starting certificate issuance/renewal in the background; see system log for progress."
+	echo 'Issuances/renewals can be aborted with `service acme abort`.'
 	rc_procd load_and_run
 }
+
+abort() {
+	procd_lock
+	if running "$@"; then
+		procd_kill "$(basename ${basescript:-$initscript})" "$1"
+		echo "Aborting certificate issuance(s)/renewal(s); see system log for confirmation."
+	elif [ -z "$1" ]; then
+		echo "No certificate issuances/renewals running to abort!"
+		exit 1
+	else
+		echo "No certificate issuance/renewal \"$1\" running to abort!"
+		exit 1
+	fi
+}