From 234ee56bed4042c776e8ba3df0e902365bffe66b Mon Sep 17 00:00:00 2001
From: fbt <fbt@fleshless.org>
Date: Sun, 7 Jan 2018 08:36:39 +0300
Subject: [PATCH] Rudimentary support for systemd services

Signed-off-by: fbt <fbt@fleshless.org>
---
 ssm | 79 ++++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 60 insertions(+), 19 deletions(-)

diff --git a/ssm b/ssm
index 80d1b17..9653de7 100755
--- a/ssm
+++ b/ssm
@@ -200,6 +200,30 @@ result() {
 	printf '%s\n' "${msgs[$rc]}"
 }; readonly -f result
 
+read_systemd_service() {
+	declare section key value
+
+	while read -r line; do
+		[[ $line =~ ^\[(.+)\] ]] && section=${BASH_REMATCH[1],,}
+		[[ $line =~ ^([^=]+)=(.+) ]] && {
+			key=${BASH_REMATCH[1],,}
+			value=${BASH_REMATCH[2]}
+		}
+
+		case $section in
+			(service)
+				case $key in
+					(pidfile) service_pidfile=$value;;
+					(execstart) eval "service_command=( $value )";;
+					(execstop) eval "service_command_stop=( $value )";;
+					(execreload) eval "service_command_reload=( $value )";;
+					(restart) [[ $value == 'always' ]] && service_respawn=1;;
+				esac
+			;;
+		esac
+	done < "$1"
+}
+
 # Overloadable functions
 ## Start the service, write down the svc pid
 start() {
@@ -241,12 +265,7 @@ start() {
 ## Usually just sends HUP
 reload() {
 	(( service_running )) || return 3
-
-	if (( service_managed )); then
-		kill -n 1 "$service_pid"
-	else
-		kill -n "$service_reload_signal" "$service_pid"
-	fi
+	"${service_command_reload[@]}"
 }
 
 ## Stop the service
@@ -262,7 +281,8 @@ stop() {
 	else
 		(( service_running )) || return 3
 
-		nullexec kill -n "$service_stop_signal" "$service_pid" || return 1
+		"${service_command_stop[@]}" || return 1
+
 		pid_wait "$service_pid" || return 5
 		> "$service_stopped_flag"
 
@@ -404,26 +424,43 @@ main() {
 				break
 			}
 		done
+
+		# Search for a systemd service too
+		for i in {/etc/systemd,/run/systemd,/lib/systemd,/usr/lib/systemd}/system/$1.service; do
+			[[ -f "$i" ]] && {
+				service_name=$1
+				service_systemd=1
+				service_config=$i
+				read_systemd_service "$i"
+				break
+			}
+		done
 	fi
 
-	# Die if there is no such file
+	# Die if there is no service config file
 	[[ "$service_config" ]] || die 19 "Service not found: $1"
-
-	# Service name is the basename
-	service_name="${1##*/}"
 	
 	# Semi-hardcoded stuff
 	svc_pidfile="$rundir/$service_name.pid"
 
-	# Get the service defaults
-	for p in "${cfg_path[@]/%//$service_name}"; do
-		[[ -f "$p" ]] && {
-			source "$p" || die 5 "Failed to read service defaults: $p"
-		}
-	done
+	# We can handle other people's service configs, poorly
+	if (( service_systemd )); then
+		# I'm pretty sure we'll need this
+		:
+	else
+		# Service name is the basename
+		service_name="${1##*/}"
 
-	# Get the service config
-	source -- "$service_config" "${@:3}" || die 7 "Failed to read the service config: $service_config"
+		# Get the service defaults
+		for p in "${cfg_path[@]/%//$service_name}"; do
+			[[ -f "$p" ]] && {
+				source "$p" || die 5 "Failed to read service defaults: $p"
+			}
+		done
+
+		# Get the service config
+		source -- "$service_config" "${@:3}" || die 7 "Failed to read the service config: $service_config"
+	fi
 	
 	# Legacy
 	[[ "$service_args" ]] && service_command=( "${service_command[@]}" "${service_args[@]}" )
@@ -460,6 +497,10 @@ main() {
 		fi
 	fi
 
+	# The stop and reload commands need the service pid
+	default service_command_stop    kill -n "$service_stop_signal" "$service_pid"
+	default service_command_reload  kill -n "$service_reload_signal" "$service_pid"
+
 	# Maybe the service is enabled?
 	if [[ -f "$service_enabled_flag" ]]; then
 		# Yay, it is!