Add `systemd` config for `Promtail` monitoring `nomad`.

cookbooks/nomad/files/lib/systemd/system/promtail-nomad.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=Grafana Promtail
+Documentation=https://github.com/grafana/loki
+After=network-online.target
+
+[Service]
+User=root
+Restart=always
+ExecStart=/usr/local/bin/promtail --config.file=/etc/promtail/nomad.yaml
+
+[Install]
+WantedBy=multi-user.target

cookbooks/nomad/setup.rb

@@ -79,3 +79,15 @@ template '/etc/promtail/nomad.yaml' do
 
   notifies :restart, 'service[promtail-nomad]'
 end
+
+# Deploy the `systemd` configuration:
+remote_file '/lib/systemd/system/promtail-nomad.service' do
+  owner 'root'
+  group 'root'
+  mode '644'
+end
+
+# Service setting:
+service 'promtail-nomad' do
+  action [ :enable, :restart ]
+end