nut: Configure upsmon

`upsmon` is the component of NUT that tracks the status of UPSs and
reacts to their changing by sending notifications and/or shutting down
the system.  It is a networked application that can run on any system;
it can run on a different system than `upsd`, and indeed can run on
multiple systems simultaneously.

Each system that runs `upsmon` will need a username and password for
each UPS it will monitor.  Using the CUE [function pattern][0], I've
made it pretty simple to declare the necessary values under
`nut.monitor`.

[0]: https://cuetorials.com/patterns/functions/

app/nut/schema/schema.cue

@@ -26,8 +26,25 @@ package schema
 	port:    int
 }
 
+#NutMonitorSystem: {
+	system:     string
+	powervalue: int
+	username:   string
+	password:   string
+	role:       "primary" | "secondary"
+}
+
+#NutMonitor: {
+	monitor: [...#NutMonitorSystem]
+	minsupplies:  int | *1
+	shutdowncmd?: string
+	notifycmd?:   string
+}
+
 #Nut: {
 	listen: #Listen
 	ups: [string]:   #Ups
 	users: [string]: #User
+
+	monitor?: #NutMonitor
 }

app/nut/templates.cue

@@ -51,3 +51,26 @@ templates: containerudev.templates + [
 		}
 	},
 ]
+
+monitor: templates: [
+	{
+		template: "nut/upsmon.conf"
+		dest:     "/etc/ups/upsmon.conf"
+		owner:    "root"
+		group:    "nut"
+		mode:     "u=rw,g=r,o="
+		hooks: {
+			changed: [{run: "systemctl try-reload-or-restart nut-server"}]
+		}
+	},
+	{
+		template: "nut/nut-monitor.container"
+		dest:     "/etc/containers/systemd/nut-monitor.container"
+		hooks: {
+			changed: [
+				{run: "systemctl daemon-reload", immediate: true},
+				{run: "systemctl restart nut-monitor"},
+			]
+		}
+	},
+]

env/prod/nut.cue

@@ -2,6 +2,8 @@ package prod
 
 import "du5t1n.me/cfg/app/nut/schema"
 
+ups_server: "nut.pyrocufflink.blue"
+
 nut: schema.#Nut & {
 	listen: {
 		address: "::"
@@ -56,6 +58,25 @@ nut: schema.#Nut & {
 	}
 }
 
+#nut_monitor: {
+	#server:   string | *ups_server
+	#username: string
+	#role:     "primary" | *"secondary"
+
+	monitor: [
+		for k, v in nut.ups {
+			{
+				system:     k + "@" + #server
+				powervalue: 1
+				username:   #username
+				password:   nut.users[#username].password
+				role:       #role
+			}
+		},
+	]
+	minsupplies: 1
+}
+
 let _nut = nut
 
 collectd: nut: schema.#CollectdNut & {

host/nut0.pyrocufflink.blue.cue

@@ -6,4 +6,10 @@ import (
 
 nut: prod.nut
 
+nut: monitor: prod.#nut_monitor & {
+	#server:   "localhost"
+	#username: "upsmon"
+	#role:     "primary"
+}
+
 collectd: prod.collectd

instructions/nut0.pyrocufflink.blue.cue

@@ -10,5 +10,6 @@ import (
 render: list.Concat([
 	collectd.templates,
 	nut.templates,
+	nut.monitor.templates,
 	nut.collectd.templates,
 ])

templates/nut/nut-monitor.container

@@ -0,0 +1,24 @@
+# vim: set ft=systemd :
+[Unit]
+Description=Network UPS Tools - power device monitor and shutdown controller
+Wants=network-online.target
+After=network-online.target
+After=nut-server.service
+
+[Container]
+Image=git.pyrocufflink.net/containerimages/nut:latest
+Pull=newer
+Exec=upsmon -F
+User=nut
+RunInit=true
+Mount=type=tmpfs,dest=/run/nut,chown=true
+Volume=/etc/ups:/etc/ups:ro
+ReadOnly=true
+VolatileTmp=true
+Network=host
+
+[Service]
+ExecReload=podman exec systemd-%N upsmon -c reload
+
+[Install]
+WantedBy=multi-user.target

templates/nut/upsmon.conf

@@ -0,0 +1,28 @@
+{% for monitor in nut.monitor.monitor -%}
+MONITOR {{ monitor.system }} {{ monitor.powervalue }} {{ monitor.username }} {{ monitor.password | decrypt }} {{ monitor.role }}
+{% endfor %}
+MINSUPPLIES {{ nut.monitor.minsupplies }}
+{% if nut.monitor.shutdowncmd is defined -%}
+SHUTDOWNCMD "{{ nut.monitor.shutdowncmd }}"
+{% endif -%}
+{% if nut.monitor.notifycmd is defined -%}
+NOTIFYCMD {{ nut.monitor.notifycmd }}
+{% endif %}
+POLLFREQ 5
+POLLFREQALERT 5
+HOSTSYNC 15
+DEADTIME 15
+POWERDOWNFLAG /run/killpower
+NOTIFYFLAG ONLINE	SYSLOG+EXEC
+NOTIFYFLAG ONBATT	SYSLOG+EXEC
+NOTIFYFLAG LOWBATT	SYSLOG+EXEC
+NOTIFYFLAG FSD	SYSLOG+EXEC
+NOTIFYFLAG COMMOK	SYSLOG+EXEC
+NOTIFYFLAG COMMBAD	SYSLOG+EXEC
+NOTIFYFLAG SHUTDOWN	SYSLOG+EXEC
+NOTIFYFLAG REPLBATT	SYSLOG+EXEC
+NOTIFYFLAG NOCOMM	SYSLOG+EXEC
+NOTIFYFLAG NOPARENT	SYSLOG+EXEC
+RBWARNTIME 43200
+NOCOMMWARNTIME 300
+FINALDELAY 5