Deploy Promtail to all non-Kubernetes nodes

All the stand-alone FCOS hosts now have Promtail running, forwarding
_systemd_ journal messages to Grafana Loki.  The Kubernetes nodes will
have Promtail deployed as a Kubernetes pod.

I would really like to come up with a way to define variables for groups
of hosts, so that I do not have to add `promtail: prod.#promtail` to
every host's values file individually...

host/nut0.pyrocufflink.blue.cue

@@ -4,15 +4,16 @@ import (
 	"du5t1n.me/cfg/env/prod"
 )
 
+ssh:  prod.ssh
+sudo: prod.sudo
+
+promtail: prod.#promtail
+
+collectd: prod.collectd
+
 nut: prod.nut
 
 nut: monitor: prod.#nut_monitor & {
 	#server:   "localhost"
 	#username: "upsmon"
 }
-
-collectd: prod.collectd
-
-ssh: prod.ssh
-
-sudo: prod.sudo

host/nvr1.pyrocufflink.blue.cue

@@ -5,12 +5,13 @@ import (
 	"du5t1n.me/cfg/app/nut/schema"
 )
 
+ssh:  prod.ssh
+sudo: prod.sudo
+
+promtail: prod.#promtail
+
 nut: monitor: schema.#NutMonitor
 
 nut: monitor: prod.#nut_monitor & {
 	#username: "nvr1"
 }
-
-ssh: prod.ssh
-
-sudo: prod.sudo

host/serial1.pyrocufflink.blue.cue

@@ -6,3 +6,5 @@ import (
 
 ssh:  prod.ssh
 sudo: prod.sudo
+
+promtail: prod.#promtail

instructions/nut0.pyrocufflink.blue.cue

@@ -5,13 +5,15 @@ import (
 
 	"du5t1n.me/cfg/app/collectd"
 	"du5t1n.me/cfg/app/nut"
+	"du5t1n.me/cfg/app/promtail"
 	"du5t1n.me/cfg/env/prod"
 )
 
 render: list.Concat([
+	prod.templates,
 	collectd.templates,
+	promtail.templates,
 	nut.templates,
 	nut.monitor.templates,
 	nut.collectd.templates,
-	prod.templates,
 ])

instructions/nvr1.pyrocufflink.blue.cue

@@ -4,11 +4,13 @@ import (
 	"list"
 
 	"du5t1n.me/cfg/app/nut"
+	"du5t1n.me/cfg/app/promtail"
 	"du5t1n.me/cfg/env/prod"
 )
 
 render: list.Concat([
+	prod.templates,
+	promtail.templates,
 	nut.sysusers.templates,
 	nut.monitor.templates,
-	prod.templates,
 ])

instructions/serial1.pyrocufflink.blue.cue

@@ -4,10 +4,12 @@ import (
 	"list"
 
 	"du5t1n.me/cfg/app/collectd"
+	"du5t1n.me/cfg/app/promtail"
 	"du5t1n.me/cfg/env/prod"
 )
 
 render: list.Concat([
-	collectd.templates,
 	prod.templates,
+	collectd.templates,
+	promtail.templates,
 ])