examples, oneshot services rework

Signed-off-by: fbt <fbt@fleshless.org>

README.md

@@ -8,6 +8,9 @@ Services
 A service is a script in the ssm's init.d directory.  
 By default it's /etc/ssm/services for system services and $XDG_CONFIG_HOME/ssm/services for user ones.
 
+Note that they are BASH scripts that get sourced by `ssm`. Same pitfalls apply.
+Hopefully, you won't have to do complex logic in the services.
+
 ## Global settings
 
 * `cgroups = 0` — Enable cgroup-related features.
@@ -41,4 +44,4 @@ Optional settings (incomplete list):
 * `service_oneshot = no` — The service is supposed to do something and die instead of daemonizing.
 * `service_signals_passthru` — Array, empty by default. Which signals should the svc pass directly to the service mainpid. This is dangerous, use with caution.
 
-Quote your expansions btw. This is still BASH.
+Mind your expansions.

examples/services/iptables

@@ -0,0 +1,11 @@
+#!/usr/bin/env ssm
+
+service_oneshot = true
+service_command = /usr/bin/false
+
+service::pre_start() {
+	cat <<- EOF
+		Please don't. Use ferm or any other wrapper.
+		You will just reinvent one in here anyway.
+	EOF
+}

examples/services/nginx

@@ -0,0 +1,8 @@
+#!/usr/bin/env ssm
+
+service_respawn = on-failure
+service_command = /usr/bin/nginx
+service_pidfile = /run/nginx.pid
+
+# Do not reload the service if the config test fails.
+pre_reload() { "$service_command" -t "$@"; }

examples/services/rc.local

@@ -0,0 +1,9 @@
+#!/usr/bin/env ssm
+
+service_type = oneshot
+service_command = /etc/rc.local
+
+pre_start() {
+	# Do nothing, successfully, if /etc/rc.local is not executable.
+	[[ -x "/etc/rc.local" ]] || die 0
+}

examples/services/sshd

@@ -0,0 +1,10 @@
+#!/usr/bin/env ssm
+
+service_respawn = always
+service_command = /usr/bin/sshd -D -f "/etc/ssh/sshd_config"
+
+pre_start() {
+	if ! [[ -e "/etc/ssh/ssh_host_key" ]]; then
+		ssh-keygen -A
+	fi
+}

examples/services/tinc

@@ -0,0 +1,7 @@
+#!/usr/bin/env ssm
+
+# This trick was neat back in 2011, I swear
+var tinc_network = "${service_name##*-}"
+
+service_respawn = on-failure
+service_command = /usr/bin/tincd -D -n "$tinc_network"

examples/ssm.conf

@@ -0,0 +1,11 @@
+# This is actually a bash script
+# Everything in ssm is a bash script.
+
+# Enable cgroup-related functions.
+# This requires quite specific setup that is undocumented as of yet, sorry.
+#cgroups = 0
+
+# You can also set service-level options here, as local defaults.
+# I really do not advise doing that, but you *can*.
+# For example:
+#service_workdir = /

ssm

@@ -189,7 +189,7 @@ svc() {
 
 		rm -f "$svc_pidfile" "$service_pidfile" "$service_ready_flag"
 
-		die 0
+		die "$job_exit"
 	}; trap 'svc::cleanup' TERM
 
 	svc::reload() {
@@ -229,11 +229,7 @@ svc() {
 
 		# Wait for the process to exit and record the exit code
 		# This depends on a few things
-		if service_managed; then
+		if service_own_pidfile; then
-			printf '%s' "$job_pid" > "$service_pidfile"
-
-			wait "$job_pid"; job_exit=$?
-		else
 			# We need to wait for the service to write down its pidfile
 			until service_pidfile is file; do
 				(( counter >= service_pidfile_timeout*10 )) && {
@@ -246,10 +242,16 @@ svc() {
 
 			read -r job_pid < "$service_pidfile"
 
-			# We consider any termination of an unmanaged service to be a failure
+			# We consider any termination of a service with its own pidfile
+			# to be a failure
 			anywait "$job_pid"; job_exit=127
+		else
+			printf '%s' "$job_pid" > "$service_pidfile"
+
+			wait "$job_pid"; job_exit=$?
 		fi
 
+		# One service failure, two service failures...
 		if service_success_exit u "$job_exit"; then
 			job_success = 1
 			(( fail_counter )) && fail_counter--
@@ -258,16 +260,17 @@ svc() {
 			fail_counter++
 		fi
 
+		# Record the exit code
 		printf '%s' "$job_exit" > "$service_exit_file"
 
 		# Back off if the service exits too much AND too quickly.
-		service_respawn_force || {
+		if ! service_respawn_force; then
 			if (( fail_counter >= 3 )); then
 				printf -v date '%(%s)T'
 
 				(( (date - last_respawn) <= 5 )) && break
 			fi
-		}
+		fi
 
 		# Respawn, if necessary
 		service_respawn_flag || break
@@ -419,26 +422,26 @@ start() {
 	depend "${service_depends[@]}" || return 7
 	depend_ready "${service_depends_ready[@]}" || return 7
 
-	mktmpfiles || return 13
-
 	rm -f "$service_stopped_flag"
 
+	mktmpfiles || return 13
+
+	svc "${service_command[@]}" & job=$!
+
 	if service_oneshot; then
-		spawn "${service_command[@]}"; res=$?
+		wait "$job"; res=$?
+
 		(( res )) && {
 			printf '%s' "$res" > "$service_exit_file"
-			return "$res"
+			return 17
 		}
-		printf '1' > "$service_enabled_flag"
+	fi
-	else
-		svc "${service_command[@]}" &
 
 	if timer "$service_ready_timeout" run_service_action 'ready'; then
 		set_ready
 	else
 		return 5
 	fi
-	fi
 
 	return 0
 }
@@ -457,10 +460,7 @@ reload() {
 stop() {
 	if service_oneshot; then
 		service_enabled || return 3
-
+		return 7
-		rm -f "$service_enabled_flag"
-
-		return 0
 	else
 		service_running || return 3
 
@@ -499,12 +499,12 @@ info() {
 		var _type = 'daemon'
 		var _info_items
 
-	service_oneshot && {
+	if service_oneshot; then
 		_status_label = 'Enabled'
-		_type = 'oneshot'
+		service_enabled && _status = 'yes'
-	}
+	else
-
+		service_running && _status = 'yes'
-	status && _status = 'yes'
+	fi
 
 	_info_items = \
 		"Name"            "$service_name" \
@@ -584,7 +584,6 @@ var service_pid \
 	service_logfile_out \
 	service_logfile_err \
 	service_ready_flag \
-	service_enabled_flag \
 	service_stopped_flag \
 	service_exit_file \
 	service_exit_last \
@@ -638,7 +637,7 @@ var cgroups = 0 # Enable cgroup-related functions
 var usrdir = '/usr/share/ssm'
 
 # These are not
-var service_managed = 1
+var service_own_pidfile = 0
 var service_oneshot = 0
 var service_running = 0
 var service_enabled = 0
@@ -769,7 +768,6 @@ readonly service_name
 
 # These depend on the service_name and make little sense to reconfigure.
 service_ready_flag := "$rundir/$service_name.ready"
-service_enabled_flag := "$rundir/$service_name.enabled"
 service_stopped_flag := "$rundir/$service_name.stopped"
 service_exit_file := "$rundir/$service_name.exit"
 service_cgroup_name := "$service_name"
@@ -801,8 +799,12 @@ if ! service_respawn == 'no'; then
 	esac
 fi
 
-# Unset the managed flag on services with their own pidfile
+if service_respawn_flag && service_oneshot; then
-service_pidfile && service_managed = 0
+	die 89 'Cowardly refusing to respawn a oneshot service'
+fi
+
+# Catch services with their own pidfile, set the appropriate flag.
+service_pidfile && service_own_pidfile = 1
 
 # Semi-hardcoded stuff
 svc_pidfile = "$rundir/$service_name.svc_pid"
@@ -851,12 +853,6 @@ if svc_pidfile is file; then
 	fi
 fi
 
-# Maybe the service is enabled?
-if service_enabled_flag is file; then
-	# Yay, it is!
-	service_enabled = 1
-fi
-
 # Let's see if the service was deliberately stopped
 if service_stopped_flag is file; then
 	# Ooh, it was.
@@ -867,7 +863,9 @@ fi
 if service_exit_file is file; then
 	read -r service_exit_last < "$service_exit_file"
 
-	if ! service_success_exit u "$service_exit_last"; then
+	if service_success_exit u "$service_exit_last"; then
+		service_oneshot && service_enabled = 1
+	else
 		# :(
 		service_failed = 1
 	fi
@@ -904,7 +902,8 @@ case "$2" in
 		result "$res" \
 			0 "Stopped $service_name" \
 			3 "$service_name is not running" \
-			5 "Operation timed out"
+			5 "Operation timed out" \
+			7 "Can't “stop” a oneshot service. Use reset-exit if you want to “start” the service again"
 	;;
 
 	start)
@@ -915,7 +914,8 @@ case "$2" in
 			7 "Failed to start dependencies for $service_name: ${failed_deps[@]}" \
 			9 "service_command does not exist: ${service_command[0]}" \
 			13 "Failed to create temporary files for $service_name" \
-			15 "Refusing to start $service_name: the service cgroup is not empty and \$service_cgroup_exclusive is set"
+			15 "Refusing to start $service_name: the service cgroup is not empty and \$service_cgroup_exclusive is set" \
+			17 "$service_name failed"
 	;;
 
 	reload)

ssm.conf

@@ -1,49 +0,0 @@
-# This is actually a bash script
-
-# Enable cgroup-related functions
-#cgroups = 0
-
-# Where to search for services, works as a PATH-like array.
-#service_path = "$XDG_CONFIG_HOME/ssm/services" /etc/ssm/services "$rundir/services" /usr/share/ssm/services
-
-# Service defaults
-
-## Respawn the service if it exits
-#service_respawn = 0
-
-## Working directory
-#service_workdir = '/'
-
-## How long do we wait for the service to stop
-#service_stop_timeout = 30
-
-## How long do we wait for the service to get ready
-#service_ready_timeout = 15
-
-## Signals to pass through to the service under the respawner
-#service_signals = 1 10 12
-
-## The signal to send to reload the service
-#service_reload_signal = 1
-
-## The signal to send to stop the service
-#service_stop_signal = 15
-
-## These only work with cgroups = 1:
-
-## Check if the recorded PID of the service is in the correct cgroup.
-#service_cgroup_strict = 1
-
-## Refuse to start the service if its cgroup is not empty
-#service_cgroup_exclusive = 0
-
-## Wait on all the members of the cgroup to exit when stopping the service.
-#service_cgroup_wait = 0
-
-## Send a kill signal to the members of cgroup when
-## stopping the service, and the signal to send:
-#service_cgroup_kill = 0
-#service_cgroup_kill_signal = 15
-
-# Clean up the cgroup when the service exits for any reason
-#service_cgroup_cleanup = 0